Development of rubberized geopolymer interlocking bricks

Directory of Open Access Journals (Sweden)

Bashar S Mohammed

2018-06-01

Full Text Available Waste tires contribute badly to the environment on a huge scale as they are bulky, non-biodegradable, and prone to fire and being a shelter for mosquitos and other insects. This paper reports on a novel approach towards the development of rubberized brick by utilizing crumb rubber as the sole fine aggregate in the production of geopolymer interlocking bricks. The response surface methodology (RSM from Design Experts software has been used to determine the numbers of trial mixes and their corresponding ingredients. A total of thirteen trial mixes were carried out and tested for compressive strength and the RSM model was developed to predict the design mix based on the targeted compressive strength. The mix design was obtained to be an 18 M for NaOH and 0.8 solution to fly ash ratio. The geopolymer interlocking rubberized bricks were then produced and tested for compressive strength, dimension, modulus of rupture, water absorption, initial rate of absorption, and efflorescence. The geopolymer interlocking rubberised bricks presented a low compressive and flexural strength and a high-water absorption capacity. The bricks were rated as non-effloresced and classified as 3rd class bricks which can be used as non-load bearing material. It is recommended to utilize nano silica in order to increase the strength of the brick. Keywords: Rubberized bricks, Crumb rubber, Interlocking bricks, Geopolymer, Response surface methodology

Accelerated pavement testing of thin RCC over soil cement pavements

Directory of Open Access Journals (Sweden)

Zhong Wu

2016-05-01

Full Text Available Three full-scale roller compacted concrete (RCC pavement sections built over a soil cement base were tested under accelerated pavement testing (APT. The RCC thicknesses varied from 102 mm (4 in. to 152 mm (6 in. and to 203 mm (8 in., respectively. A bi-directional loading device with a dual-tire load assembly was used for this experiment. Each test section was instrumented with multiple pressure cells and strain gages. The objective was to evaluate the structural performance and load carrying capacity of thin RCC-surfaced pavements under accelerated loading. The APT results generally indicated that all three RCC pavement sections tested in this study possessed very high load carrying capacity; an estimated pavement life in terms of equivalent single axle load (ESAL for the thinnest RCC section (i.e., RCC thickness of 102 mm evaluated was approximately 19.2 million. It was observed that a fatigue failure would be the primary pavement distress type for a thin RCC pavement under trafficking. Specifically, the development of fatigue cracking was found to originate from a longitudinal crack at the edge or in the center of a tire print, then extended and propagated, and eventually merged with cracks of other directions. Instrumentation results were used to characterize the fatigue damage under different load magnitudes. Finally, based on the APT performance of this experiment, two fatigue models for predicting the fatigue life of thin RCC pavements were developed. Keywords: Roller compacted concrete, APT, Pavement performance, Non-destructive testing, Fatigue analysis

Pavement Preservation for Elected Officials: The Inside Story of Pavement Deterioration

OpenAIRE

Olson, Jim

2012-01-01

This session is intended to provide elected officials and practitioners with an introduction to the concept of pavement preservation and its applicability within public agencies. Topics include definitions, budget planning, pavement life, road networks, alternative strategies, pavement distresses, guidelines and preservation treatments.

Outside corner and method of making in the making lead brick (plain brick) using rotary table

International Nuclear Information System (INIS)

Muhammad Awwaluddin; Samuel Praptoyo

2009-01-01

It has been developed a tool that can be used for defining angles on the fabrication of lead bricks. The angles are both outside of the lead bricks that correspond to male and female shape respectively. The lead bricks should be in accordance to ISO 7212-1986 standard which has angle tolerance 90° 0 +15 for male and 90° 0 -15 for female. The accuracy of these angles is very important to maintain the equilibrium position of the bricks so that their arrangement will not lining or collapse. A rotary table is used for the fabrication to make easier in setting up any related working apparatus and to have precision measurement result. However, a lot of operator do not know yet how to operate such a rotary table to produce angle with such an eligible tolerance. Therefore, a method of measurement in machining lead brick process using a rotary table is necessarily required. This method will be used as a reference to have angle accuracy of 0,03° in producing outside and inside angles or male and female lead bricks. (author)

Experimental study on compressive strength of sediment brick masonry

Science.gov (United States)

Woen, Ean Lee; Malek, Marlinda Abdul; Mohammed, Bashar S.; Chao-Wei, Tang; Tamunif, Muhammad Thaqif

2018-02-01

The effects of pre-wetted unit bricks, mortar type and slenderness ratio of prisms on the compressive strength and failure mode of newly developed sediment brick have been evaluated and compared to clay brick and cement-sand bricks. The results show that pre-wetted sediment brick masonry exhibits higher compressive strength of up to 20% compared to the dry sediment masonry. Using cement-lime mortar leads to lower compressive strength compared to cement mortar. However, the sediment brick masonry with the cement lime mortar exhibit higher compressive strength in comparison with cement mortar masonry. More of diagonal shear cracks have been observed in the failure mode of the sediment bricks masonry compared to clay and cement-sand bricks masonry that show mostly vertical cracks and crushing. The sediment unit bricks display compressive strength in between clay and cement-sand bricks.

A brick-architecture-based mobile under-vehicle inspection system

Science.gov (United States)

Qian, Cheng; Page, David; Koschan, Andreas; Abidi, Mongi

2005-05-01

In this paper, a mobile scanning system for real-time under-vehicle inspection is presented, which is founded on a "Brick" architecture. In this "Brick" architecture, the inspection system is basically decomposed into bricks of three kinds: sensing, mobility, and computing. These bricks are physically and logically independent and communicate with each other by wireless communication. Each brick is mainly composed by five modules: data acquisition, data processing, data transmission, power, and self-management. These five modules can be further decomposed into submodules where the function and the interface are well-defined. Based on this architecture, the system is built by four bricks: two sensing bricks consisting of a range scanner and a line CCD, one mobility brick, and one computing brick. The sensing bricks capture geometric data and texture data of the under-vehicle scene, while the mobility brick provides positioning data along the motion path. Data of these three modalities are transmitted to the computing brick where they are fused and reconstruct a 3D under-vehicle model for visualization and danger inspection. This system has been successfully used in several military applications and proved to be an effective safer method for national security.

Mechanical properties of geopolymer lightweight brick with styrofoam pellet

Science.gov (United States)

Abdullah, Mohd Mustafa Al Bakri; Tahir, Muhammad Faheem Mohd; Kadir, Aeslina Abdul; Hussin, Kamarudin; Samson, W. Saiful Iskandar W.

2017-09-01

The utilization of fly ash in brick as partial replacement of cement is gaining immense importance today, mainly on account of the improvement in the long-term durability of brick combined with ecological benefits. In this research, the lightweight brick was produced by using fly ash (class F) as a main material to replace Ordinary Portland Cement (OPC) in the composition of brick. Class F Fly Ash was mixed with an alkaline activator solution (a mixture of sodium silicate and NaOH), and styrofoam pellet was added to the geopolymer mixture to produce lightweight brick. The brick was prepared in two methods that is wet method and dry method due to different brick composition which is dry method for composition with sand and wet method for composition without sand. The bricks were cured in room temperature at 7 aging days. After 7 days, the compressive strength, water absorption, and density of the brick were investigated, where the optimum ratio for the best bricks has been determined from the lightweight density and has compressive strength more than minimum standard requirement. The best bricks are further produce for curing at 60°C in oven at 28 aging days. Those bricks also were characterized using optical microscope to measure the distribution of styrofoam in brick structure. From the result obtained, the brick that cured at 60°C in oven at 28 aging days has high strength compare to brick that cured in room temperature and at 7 day cured. The water absorption is decreasing as the curing temperature and aging days increased whereas density is increasing.

Bricks as indicators for an urban soil genesis

Science.gov (United States)

Nehls, Thomas; Rokia, Sarah; Schwartz, Christophe; Wessolek, Gerd

2013-04-01

Bricks can be considered as anthropogenic markers since they are regularly found in urban soils worldwide. They are among the most resistent residues of building materials, therefore are called technogenic substrates. They have been dumped to urban soils since more than 4000 years and can be dated back to their burning using thermoluminescence. In Berlin, bricks have been piled up to more than 37 rubble mountains in the city after WW II. The devils mountain, the most prominent of them is higher than 60m. However, bricks are known not to be isolated in the soil but to fulfill soil functions due to their porosity. Therefore, they are nice research objects for soil scientists. The purpose of this study is to investigate abundance and functions of bricks in urban soils, focusing on plant nutrition and contamination aspects. Three different Berlin urban soils have been studied for their brick contents in the coarse and fine earth fractions by endless hand sorting. Light and scanning electron microscopy was then employed to investigate the bricks for proofs of plant roots. Third, CEC, pH, EC, Corg, nutrient storage (XRF) and availability (2:1 extract, ion chromatography, AAS) of bricks and fine earth fractions of the corresponding soil horizons have been investigated. The fine earth fractions of the investigated soils contain 3 to 5% of bricks, while the coarse fractions contain up to 50%. We found roots entering brick pores or at least attached to brick surfaces. Therefore, plants can use the water and nutrients stored in bricks. The CEC of bricks is grain size dependent and reaches a maximum of 6 cmolc kg-1 for particles smaller than 0.063 mm. This dependency is not explained by a low pore connectivity. Rather, it is the result of the restricted diffusion into the brick pore system due to the short shaking time in the CEC analysis protocol. From the nutrient storage and availabilities we conclude that bricks can better supply plants with K, Mg, Ca and S than the bulk

Can an Electron Rotate a Brick?

Science.gov (United States)

Bohren, Craig F.

2009-01-01

In "The Theory of Almost Everything", Robert Oerter asserts the following: "Take a beam of electrons that are all spinning in the same direction and fire it at, say, a brick. If you could keep this up for long enough, and if there were no other forces acting on the brick, the electrons would transfer their rotation to the brick, and it would begin…

Comparative Study on the Cost of Building Public House Construction Using Red Brick and Interlock Brick Building Material in the City of Banda Aceh

Science.gov (United States)

Malahayati, Nurul; Hayati, Yulia; Nursaniah, Cut; Firsa, T.; Fachrurrazi; Munandar, Aris

2018-05-01

Red brick and interlocking brick are the building materials that are often used for wall installation work on houses construction. In the development of building materials technology and cost savings, interlocking brick can be alternative to replace red bricks. In Aceh Province, the use of interlocking bricks is less popular compared to other big cities in Indonesia. Interlocking brick is made from a mixture of clay, concrete sand and compacted cement and one of the environmentally friendly materials because it does not burn the process like red brick material. It is named interlocking brick because the installation method is locked together and it serves as a structural and partition wall of residential buildings. The aims of this study are to compare the cost of building a house in Banda Aceh City using red brick and interlock brick building materials. The data were obtained from interviews and questionnaires distributed to respondents who had built houses in Banda Aceh City. The results concluded that the house construction cost using interlock brick offer lower construction cost at comparable quality rather than using red brick.

Hygrothermal behavior for a clay brick wall

Science.gov (United States)

Allam, R.; Issaadi, N.; Belarbi, R.; El-Meligy, M.; Altahrany, A.

2018-06-01

In Egypt, the clay brick is the common building materials which are used. By studying clay brick walls behavior for the heat and moisture transfer, the efficient use of the clay brick can be reached. So, this research studies the hygrothermal transfer in this material by measuring the hygrothermal properties and performing experimental tests for a constructed clay brick wall. We present the model for the hygrothermal transfer in the clay brick which takes the temperature and the vapor pressure as driving potentials. In addition, this research compares the presented model with previous models. By constructing the clay brick wall between two climates chambers with different boundary conditions, we can validate the numerical model and analyze the hygrothermal transfer in the wall. The temperature and relative humidity profiles within the material are measured experimentally and determined numerically. The numerical and experimental results have a good convergence with 3.5% difference. The surface boundary conditions, the ground effect, the infiltration from the closed chambers and the material heterogeneity affects the results. Thermal transfer of the clay brick walls reaches the steady state very rapidly than the moisture transfer. That means the effect of using only the external brick wall in the building in hot climate without increase the thermal resistance for the wall, will add more energy losses in the clay brick walls buildings. Also, the behavior of the wall at the heat and mass transfer calls the three-dimensional analysis for the whole building to reach the real behavior.

Hygrothermal behavior for a clay brick wall

Science.gov (United States)

Allam, R.; Issaadi, N.; Belarbi, R.; El-Meligy, M.; Altahrany, A.

2018-01-01

In Egypt, the clay brick is the common building materials which are used. By studying clay brick walls behavior for the heat and moisture transfer, the efficient use of the clay brick can be reached. So, this research studies the hygrothermal transfer in this material by measuring the hygrothermal properties and performing experimental tests for a constructed clay brick wall. We present the model for the hygrothermal transfer in the clay brick which takes the temperature and the vapor pressure as driving potentials. In addition, this research compares the presented model with previous models. By constructing the clay brick wall between two climates chambers with different boundary conditions, we can validate the numerical model and analyze the hygrothermal transfer in the wall. The temperature and relative humidity profiles within the material are measured experimentally and determined numerically. The numerical and experimental results have a good convergence with 3.5% difference. The surface boundary conditions, the ground effect, the infiltration from the closed chambers and the material heterogeneity affects the results. Thermal transfer of the clay brick walls reaches the steady state very rapidly than the moisture transfer. That means the effect of using only the external brick wall in the building in hot climate without increase the thermal resistance for the wall, will add more energy losses in the clay brick walls buildings. Also, the behavior of the wall at the heat and mass transfer calls the three-dimensional analysis for the whole building to reach the real behavior.

Measurement of natural radionuclides in bricks and brick-making clays from Cuddalore district, Tamilnadu, India

International Nuclear Information System (INIS)

Viruthagirl, G.; Rajamanan, B.; Ravisankar, R.; Thilaivelavan, K.; Chandrasekaran, A.; Meenkshisundram, V.

2010-01-01

In India, bricks as building materials are mainly prepared by clay using the deposited sediments of rivers, and the radionuclide contents in bricks and brick-making clays should vary with origin and geological condition. In this paper, the radionuclide contents of these materials from river bank areas of Cuddalore district, Tamilnadu India are measured by gamma ray spectrometer using NaI (Tl) detector, and compared with those of other countries. The radiation hazard indices, which are evaluated by radium-equivalent (Raeq) activity, are lower than that of NEA-OECD. (authors)

Experimental characterisation of Polyethylene Terephthalate (PET) bottle Eco-bricks

International Nuclear Information System (INIS)

Taaffe, Jonathan; O’Sullivan, Seán; Rahman, Muhammad Ekhlasur; Pakrashi, Vikram

2014-01-01

Highlights: • Characterisation of a novel “Eco-brick” by recycling PET bottles and plastic waste. • Eco-bricks have properties for possible uses in construction. • Consistent manufacturing of Eco-bricks demonstrated to be possible. • Weight of Eco-bricks has a nearly linear relationship with mechanical strength. • Light passage and sound reduction potential of Eco-bricks shown to be good. - Abstract: This paper addresses the issue of recycling waste plastic by considering the feasibility of use of Eco-bricks for constructional purposes. The Eco-bricks are formed by packing plastic within Polyethylene Terephthalate (PET) bottles. Guidelines were provided for the construction of Eco-bricks. Experiments were carried out to characterise some of the properties of these bricks. Compression test, sound insulation assessment and light transmission were considered in this regard and compared with traditional construction materials and conditions. Possible applications of Eco-bricks were discussed. The paper presents the first attempt to characterise these bricks and the results encourage future use of them to a significantly wider extent and for various purposes

Radiation shielding bricks

International Nuclear Information System (INIS)

Crowe, G.J.W.

1983-01-01

A radiation shielding brick for use in building dry walls to form radiation proof enclosures and other structures is described. It is square in shape and comprises a sandwich of an inner layer of lead or similar shielding material between outer layers of plastics material, for structural stability. The ability to mechanically interlock adjacent bricks is provided by shaping the edges as cooperating external and internal V-sections. Relatively leak-free joints are ensured by enlarging the width of the inner layer in the edge region. (author)

Fatigue cracking in road pavement

Science.gov (United States)

Mackiewicz, P.

2018-05-01

The article presents the problem of modelling fatigue phenomena occurring in the road pavement. The example of two selected pavements shows the changes occurring under the influence of the load in different places of the pavement layers. Attention is paid to various values of longitudinal and transverse strains generated at the moment of passing the wheel on the pavement. It was found that the key element in the crack propagation analysis is the method of transferring the load to the pavement by the tire and the strain distribution in the pavement. During the passage of the wheel in the lower layers of the pavement, a complex stress state arises. Then vertical, horizontal and tangent stresses with various values appear. The numerical analyses carried out with the use of finite element methods allowed to assess the strain and stress changes occurring in the process of cracking road pavement. It has been shown that low-thickness pavements are susceptible to fatigue cracks arising "bottom to top", while pavements thicker are susceptible to "top to bottom" cracks. The analysis of the type of stress allowed to determine the cracking mechanism.

Evaluating the performance of sustainable perpetual pavements using recycled asphalt pavement in China

Directory of Open Access Journals (Sweden)

Saud A. Sultan

2016-10-01

Full Text Available The vast highways network in China is moving from the phase of construction to the phase of maintenance, and with the introduction of new technique of perpetual pavement in last decade, it is necessary to consider recycling as one of the promising solutions for rehabilitation of old asphalt concrete pavement and ultimately to convert them into perpetual pavements. The aim is to reuse the existing pavement materials for several reasons, mainly to preserve natural resources such as aggregates, and to satisfy economic requirements by reducing the cost of highway construction and rehabilitation. A detailed testing program has been carried out on recycled asphalt pavements materials (RAP to evaluate their mechanical and structural characteristics to be used for the construction and rehabilitation of road pavements. Different types of RAP mixes have been stabilized by Portland cement to find the most suitable one from the point of view of design, construction, economy and environment. The analysis of life cycle costs has been carried out using system analysis and management of pavement program (SAMP5. The analysis of life cycle costs showed that the use of Portland cements with small percentages improves the structural characteristics of recycled asphalt materials to be used as stabilized base pavement layers for new or rehabilitated old road pavements and also for the construction and rehabilitation of perpetual pavements. A large amount of savings in construction and rehabilitation cost has been achieved by the use of stabilized RAP materials in addition to important contributions to the environment and preserving of natural resources.

Indiana Pavement Preservation Program

OpenAIRE

Ong, Ghim Ping (Raymond); Nantung, Tommy E.; Sinha, Kumares C.

2010-01-01

State highway agencies are facing immense pressure to maintain roads at acceptable levels amidst the challenging financial and economic situations. In recent years, pavement preservation has been sought as a potential alternative for managing the pavement assets, believing that it would provide a cost-effective solution in maintaining infrastructural conditions and meeting user expectations. This study explores the potential of pavement preservation concepts in managing the agency‘s pavement ...

Moisture transport over the brick/mortar interface

NARCIS (Netherlands)

Brocken, H.J.P.; Pel, L.

1995-01-01

The moisture transport in brick, mortar that was cured separately, and combined brick/mortar samples was studied using NMR. The experimental results show that the mortar is less permeable if it is cured bonded to the brick instead of cured separately. Models of the moisture transport are usually

Evaluating life cycle costs of perpetual pavements in China using operational pavement management system

Directory of Open Access Journals (Sweden)

Saud A. Sultan

2016-10-01

Full Text Available Highway transportation is considered as vital factor in China’s economic growth; many high grade highways have been constructed in China during the last decades. The research and application of perpetual asphalt pavement (PP technology have been deployed in China since 2000. The semi-rigid pavement has been normally considered as typical pavement of high class highways in the design according to the Chinese experience. The objective of this research is to evaluate the performance of different Chinese perpetual pavements using operational pavement management system and to examine its suitability for use in the design and construction of more economical and durable pavements. It has been found that the use of thin asphalt layers over semi-rigid pavement foundation in PP structure will create more sustainable, economical, and durable PP structures in comparison with typical thick asphalt layers PP structures.

Thermal stability analysis under embankment with asphalt pavement and cement pavement in permafrost regions.

Science.gov (United States)

Junwei, Zhang; Jinping, Li; Xiaojuan, Quan

2013-01-01

The permafrost degradation is the fundamental cause generating embankment diseases and pavement diseases in permafrost region while the permafrost degradation is related with temperature. Based on the field monitoring results of ground temperature along G214 Highway in high temperature permafrost regions, both the ground temperatures in superficial layer and the annual average temperatures under the embankment were discussed, respectively, for concrete pavements and asphalt pavements. The maximum depth of temperature field under the embankment for concrete pavements and asphalt pavements was also studied by using the finite element method. The results of numerical analysis indicate that there were remarkable seasonal differences of the ground temperatures in superficial layer between asphalt pavement and concrete pavement. The maximum influencing depth of temperature field under the permafrost embankment for every pavement was under the depth of 8 m. The thawed cores under both embankments have close relation with the maximum thawed depth, the embankment height, and the service time. The effective measurements will be proposed to keep the thermal stabilities of highway embankment by the results.

Strength properties of interlocking compressed earth brick units

Science.gov (United States)

Saari, S.; Bakar, B. H. Abu; Surip, N. A.

2017-10-01

This study presents a laboratory investigation on the properties of interlocking compressed earth brick (ICEB) units. Compressive strength, which is one of the most important properties in masonry structures, is used to determine masonry performance. The compressive strength of the ICEB units was determined by applying a compressive strength test for 340 units from four types of ICEB. To analyze the strength of the ICEB units, each unit was capped by a steel plate at the top and bottom to create a flat surface, and then ICEB was loaded until failure. The average compressive strength of the corresponding ICEB units are as follows: wall brick, 19.15 N/mm2; beam brick, 16.99 N/mm2; column brick, 13.18 N/mm2; and half brick, 11.79 N/mm2. All the ICEB units had compressive strength of over 5 N/mm2, which is the minimum strength for a load-bearing brick. This study proves that ICEB units may be used as load-bearing bricks. The strength of ICEBs is equal to that of other common bricks and blocks that are currently available in the market.

Utilization of Blended Waste Materials in Bricks

Directory of Open Access Journals (Sweden)

Muhammad Ekhlasur Rahman

2018-01-01

Full Text Available Cement is considered a key raw material for brick production. However, excessive use of cement leads to a negative environment impact. Cement replaced with locally available waste materials has a significant potential to address this environmental impact, especially in the construction industry by contributing to cleaner production. The objective of this research is to investigate the performance of brick where cement is replaced by fly ash and palm oil fuel ash, waste materials typically available in Malaysia, where the construction industry is on the rise. To determine the performance of these bricks, a compressive strength test, a water absorption test, and a thermogravimetric analysis were carried out at different percentage combinations of fly ash and palm oil fuel ash. The results from the tests reveal that both fly ash and palm oil fuel ash incorporated bricks satisfy Class 1 and Class 2 load-bearing brick requirements according to the Malaysian Standard MS76:1972 along with water absorption requirements as per ASTM C55-11. The thermogravimetric analysis study confirms that the Ca(OH2 gradually decreases due to the increase of pozzolanic material contents (fly ash and palm oil fuel ash. Moreover, these newly developed bricks cost less than the conventional bricks.

Water absorption in brick masonry

NARCIS (Netherlands)

Brocken, H.J.P.; Smolders, H.R.

1996-01-01

The water absorption in brick, mortar that was cured separately, and masonry samples was studied using NMR. Models of the moisture transport are usually formulated on the basis of a diffusion equation. In the case of water absorption in separate brick and mortar samples, the moisture diffusivity in

Performance evaluation of clay fly ash brick masonry

Energy Technology Data Exchange (ETDEWEB)

Kute, S.; Deodhar, S.V. [K.K. Wagh College of Engineering, Panchavati (India). Dept. of Civil Engineering

2003-07-01

Despite inexorable trends of automation in manufacturing industry throughout the world, the conventional brick manufacturing practices have remained largely unchanged since the dawn of civilization in India. This has imposed restrictions on quality of bricks in general. The paper highlights the results derived from an extensive experimental work on performance evaluation of brick masonry. Four types of bricks, three values of joint thickness and fineness modulus of sand, and two grades of mortar with four different proportions were used as samples. Fly ash was from Nashik Thermal Power Station in Maharashtra, India. The results show that the brick masonry of 40% fly ash bricks and mortar with 20% fly ash as replacement to cement with 1:4 and 1:6 proportion gives optimum strength and advocates use of fly ash for this combination. 8 tabs.

EXPERIMENTAL STUDY OF SOIL CEMENT BRICKS AND CHARACTERISTICS COMPRESSIVESTRENGTH OF BRICK MASONRY WALL

OpenAIRE

S. Divya; K. Nithya; S. Manoj Kumar; K. Saravanakumar

2017-01-01

This research is intended to provide detailed technical and economic information on the production of compressed cement stabilised soil bricks. These include information on suitable soil types, local stabilisers, stabilization techniques, production of compressed stabilized soil bricks and their economical value and potential. Critical review of related literatures show that soil types, proportions between soil and stabilizer and compaction pressure applied to the moist soil mix affects the q...

Drying brick masonry by electro-osmosis

DEFF Research Database (Denmark)

Ottosen, Lisbeth M.; Rörig-Dalgaard, Inge

2006-01-01

When a fine grained, porous medium is applied an electric DC field, transport of matter occurs, and the transport mechanism in focus of the present study is electro-osmosis, which is transport of water. In laboratory it was shown possible to transport water inside a brick and brick/mortar system...... movement of water towards the cathode was seen. Thus the basis for utilizing the electro-osmotic effect for drying brick masonry is present, but proper electrodes still needs to be developed....

Enhancement in thermal and mechanical properties of bricks

Directory of Open Access Journals (Sweden)

Shibib Khalid S.

2013-01-01

Full Text Available A new type of porous brick is proposed. Sawdust is initially well mixed with wet clay in order to create voids inside the brick during the firing process. The voids will enhance the total performance of the brick due to the reduction of its density and thermal conductivity and a minor reduction of its compressive stress. All these properties have been measured experimentally and good performance has been obtained. Although a minor reduction in compressive stress has been observed with increased porosity, this property has still been larger than that of the common used hollow brick. Data obtained by this work lead to a new type of effective brick having a good performance with no possibility that mortar enters inside the holes which is the case with the common used hollow bricks. The mortar has a determent effect on thermal properties of the wall since it has some higher thermal conductivity and density than that of brick which increases the wall overall density and thermal conductivity of the wall.

The "Brick Wall" Graphic Organizer

Science.gov (United States)

Matteson, Shirley M.

2016-01-01

A brick wall provides a fitting description of what happens when teachers try to teach a concept for which students are unprepared. When students are unsuccessful academically, their foundational knowledge may be missing, incomplete, or incorrect. As a result, students "hit a brick wall," and their academic progress stops because they do…

Using Tire/Pavement Interface Noise Results to Define Statistically Similar Bituminous Pavements in Massachusetts

OpenAIRE

Hencken, John; Haas, Edwin; Bennert, Thomas

2012-01-01

In October 2010, the Center for Advanced Infrastructure and Transportation (CAIT) utilized the On-Board Sound Intensity Method in Massachusetts to evaluate seven Open-Graded Friction Courses (OGFC) and eight Asphalt Rubber Gap Graded (ARGG) pavements for MassDOT. Since major concerns regarding pavement selection in the northeast revolve around winter conditions and winter maintenance, if noise level similarities could be found between ARGG and OGFC pavements, pavement engineers would be able ...

Existing pavement input information for the mechanistic-empirical pavement design guide.

Science.gov (United States)

2009-02-01

The objective of this study is to systematically evaluate the Iowa Department of Transportations (DOTs) existing Pavement Management Information System (PMIS) with respect to the input information required for Mechanistic-Empirical Pavement Des...

Mechanical properties on geopolymer brick: A review

Science.gov (United States)

Deraman, L. M.; Abdullah, M. M. A.; Ming, L. Y.; Ibrahim, W. M. W.; Tahir, M. F. M.

2017-09-01

Bricks has stand for many years as durable construction substantial, especially in the area of civil engineering to construct buildings. Brick commonly used in the structure of buildings as a construction wall, cladding, facing perimeter, paving, garden wall and flooring. The contribution of ordinary Portland cement (OPC) in cement bricks production worldwide to greenhouse gas emissions. Due to this issue, some researchers have done their study with other materials to produce bricks, especially as a by-product material. Researchers take effort in this regard to synthesizing from by-product materials such as fly ash, bottom ash and kaolin that are rich in silicon and aluminium in the development of inorganic alumina-silicate polymer, called geopolymer Geopolymer is a polymerization reaction between various aluminosilicate oxides with silicates solution or alkali hydroxide solution forming polymerized Si-O-Al-O bonds. This paper summarized some research finding of mechanical properties of geopolymer brick using by-product materials.

Shielding walls against ionizing radiation. Lead bricks

International Nuclear Information System (INIS)

1993-04-01

The standard contains specifications for the shape and requirements set for lead bricks such that they can be used to construct radiation-shielding walls according to the building kit system. The dimensions of the bricks are selected in such a way as to permit any modification of the length, height and thickness of said shielding walls in units of 50 mm. The narrow side of the lead bricks juxtaposed to one another in a wall construction to shield against radiation have to form prismatic grooves and tongues: in this way, direct penetration by radiation is prevented. Only cuboid bricks (serial nos. 55-60 according to Table 10) do not have prismatic tongues and grooves. (orig.) [de

Bricks

Energy Technology Data Exchange (ETDEWEB)

Curties, H

1921-11-18

The invention relates to the production of bricks from Norfolk and other oil shales, and consists in the introduction into the powdered shale of potassium nitrate, or sodium nitrate, or a mixture of these two substances, with the object of purifying the shale from sulfur and other deleterious substances, and of preventing the formation of cores.

An analysis of pavement heat flux to optimize the water efficiency of a pavement-watering method

International Nuclear Information System (INIS)

Hendel, Martin; Colombert, Morgane; Diab, Youssef; Royon, Laurent

2015-01-01

Pavement-watering as a technique of cooling dense urban areas and reducing the urban heat island effect has been studied since the 1990's. The method is currently considered as a potential tool for and climate change adaptation against increasing heat wave intensity and frequency. However, although water consumption necessary to implement this technique is an important aspect for decision makers, optimization of possible watering methods has only rarely been conducted. An analysis of pavement heat flux at a depth of 5 cm and solar irradiance measurements is proposed to attempt to optimize the watering period, cycle frequency and water consumption rate of a pavement-watering method applied in Paris over the summer of 2013. While fine-tuning of the frequency can be conducted on the basis of pavement heat flux observations, the watering rate requires a heat transfer analysis based on a relation established between pavement heat flux and solar irradiance during pavement insolation. From this, it was found that watering conducted during pavement insolation could be optimized to 30-min cycles and water consumption could be reduced by more than 80% while reducing the cooling effect by less than 13%. - Highlights: • The thermal effects of pavement-watering were investigated in Paris, France. • Pavement-watering was found to significantly affect pavement heat flux 5 cm deep. • When insolated, a linear relation was found between heat flux and solar radiation. • Pavement-watering did not alter its slope, but introduced a negative intercept. • Subsequent improvements of the watering period, frequency and rate are proposed

Extending the Service Life of Pavements

Science.gov (United States)

Gschwendt, Ivan

2018-03-01

The cost of road construction and expenditures on the maintenance of pavements, i.e., their whole life cost, represents a lot of money. The paper describes a procedure for a pavement management system with degradation models and estimates the length of time for the rehabilitation of an asphalt pavement. Using a theory of pavement mechanics, we calculated the stresses and strains on the layers of two pavement models. High modulus asphalt concrete, an asphalt mix with a high binder content, and an asphalt mix with binder modifications are new road building materials. Prolonging the time for the rehabilitation of pavements is possible.

Geo synthetic-reinforced Pavement systems

International Nuclear Information System (INIS)

Zornberg, J. G.

2014-01-01

Geo synthetics have been used as reinforcement inclusions to improve pavement performance. while there are clear field evidence of the benefit of using geo synthetic reinforcements, the specific conditions or mechanisms that govern the reinforcement of pavements are, at best, unclear and have remained largely unmeasured. Significant research has been recently conducted with the objectives of: (i) determining the relevant properties of geo synthetics that contribute to the enhanced performance of pavement systems, (ii) developing appropriate analytical, laboratory and field methods capable of quantifying the pavement performance, and (iii) enabling the prediction of pavement performance as a function of the properties of the various types of geo synthetics. (Author)

Pavement maintenance scheduling using genetic algorithms

OpenAIRE

Yang, Chao; Remenyte-Prescott, Rasa; Andrews, John D.

2015-01-01

This paper presents a new pavement management system (PMS) to achieve the optimal pavement maintenance and rehabilitation (M&R) strategy for a highway network using genetic algorithms (GAs). Optimal M&R strategy is a set of pavement activities that both minimise the maintenance cost of a highway network and maximise the pavement condition of the road sections on the network during a certain planning period. NSGA-II, a multi-objective GA, is employed to perform pavement maintenance optimisatio...

Water absorption characteristic of interlocking compressed earth brick units

Science.gov (United States)

Bakar, B. H. Abu; Saari, S.; Surip, N. A.

2017-10-01

This study aims to investigate the water absorption characteristic of interlocking compressed earth brick (ICEB) units. Apart from compressive strength, water absorption is an important property in masonry. This property can affect the quality of the brick itself and the bond strength between the brick and mortar in masonry structures and can result in reducing its strength properties. The units were tested for 24 h water absorption and 5 h boiling water absorption. A total of 170 ICEB units from four ICEB types underwent both tests. For the 24 h water absorption, the ICEB units were dried in the oven for 24 h and then cooled before being weighed. Thereafter, each brick was immersed in water for 24 h and weighed. The same specimens used for the 24 h water absorption test were re-used for the 5 h boiling water absorption test. After completing the 24 h water absorption test, the brick was boiled for 5-hours and weighed. The highest water absorption for the ICEBs in the 24-hour water absorption and 5 h boiling water absorption tests are 15.09% and 17.18%, respectively. The half brick has the highest water absorption (15.87%), whereas the beam brick has the lowest (13.20%). The water absorption of an ICEB unit is higher than that of normal bricks, although the water absorption of the former remains below the maximum rate of the brick water absorption (21%).

Properties of bricks produced from Greenlandic marine sediments

DEFF Research Database (Denmark)

Bertelsen, Ida Maria Gieysztor; Belmonte, Louise Josefine; Chen, Wan

2015-01-01

miniature bricks (54×54×60 mm3) of MS from Sisimiut. Brick pellets were prepared in order to determine an optimal composition and production method, based on investigations of the firing temperature and time,forming pressure, initial forming water content, and content of granite waste (CR). Miniature bricks......This study investigated the possibility of a local brick production from fine grained marine sediments (MS) near Sisimiut, Greenland. The assessment is based on the physical and mechanical properties of clay bricks concerning the resistance to the harsh, Arctic weather conditions, together...... were then prepared according to the optimal conditions and formed at a pressure of 20 MPa, fired at 1020 ºC for 3.5 days at the brickwork Wienerberger Tegl in Helsinge, Denmark. The durability properties such as porosity, water absorption, bulk density, linear shrinkage, and compressive strength (only...

Compressive strength of brick masonry made with weak mortars

DEFF Research Database (Denmark)

Pedersen, Erik Steen; Hansen, Klavs Feilberg

2013-01-01

in the joint will ensure a certain level of load-carrying capacity. This is due to the interaction between compression in the weak mortar and tension in the adjacent bricks. This paper proposes an expression for the compressive strength of masonry made with weak lime mortars (fm... of masonry depends only on the strength of the bricks. A compression failure in masonry made with weak mortars occurs as a tension failure in the bricks, as they seek to prevent the mortar from being pressed out of the joints. The expression is derived by assuming hydrostatic pressure in the mortar joints......, which is the most unfavourable stress distribution with respect to tensile stresses in bricks. The expression is compared with the results of compression tests of masonry made with weak mortars. It can take into account bricks with arbitrary dimensions as well as perforated bricks. For a stronger mortar...

Stormwater infiltration and surface runoff pollution reduction performance of permeable pavement layers.

Science.gov (United States)

Niu, Zhi-Guang; Lv, Zhi-Wei; Zhang, Ying; Cui, Zhen-Zhen

2016-02-01

In this paper, the laboratory-scale permeable pavement layers, including a surface permeable brick layer, coarse sand bedding layers (thicknesses = 2, 3.5, and 5 cm), and single-graded gravel sub-base layers (thicknesses = 15, 20, 25, and 30 cm), were built to evaluate stormwater infiltration and surface runoff pollution reduction performance. And, the infiltration rate (I) and concentrations of suspended solids (SS), total phosphorus (TP), chemical oxygen demand (COD), ammonia nitrogen, and total nitrogen (TN) were measured under the simulated rainfall intensity of 72.4 mm/h over duration of 60 min. The results indicate that the thickness factor primarily influences the infiltration rate and pollutant removal rate. The highest steady infiltration rate was for surface brick layer 51.0 mm/h, for 5-cm sand bedding layer 32.3 mm/h, and for 30-cm gravel sub-base layer 42.3 mm/h, respectively. The SS average removal rate was relative higher (79.8 ∼ 98.6 %) for all layers due to the interception and filtration. The average removal rates of TP and COD were for surface layer 71.2 and 24.1 %, for 5-cm bedding layer 54.8 and 9.0 %, and for 20-cm sub-base layer 72.2 and 26.1 %. Ammonia nitrogen and TN cannot steadily be removed by layers according to the experiment results. The optimal thickness of bedding sands was 5 cm, and that of sub-base gravels was 20 ∼ 30 cm.

VALIDITY OF GARBER MODEL IN PREDICTING PAVEMENT CONDITION INDEX OF FLEXIBLE PAVEMENT IN KERBALA CITY

Directory of Open Access Journals (Sweden)

Hussein A. Ewadh

2018-05-01

Full Text Available Pavement Condition Index (PCI is one of the important basics in pavement maintenance management system (PMMS, and it is used to evaluate the current and future pavement condition. This importantance in decision making to limit the maintenance needs, types of treatment, and maintenance priority. The aim of this research is to estimate the PCI value for flexible pavement urban roads in the study area (kerbala city by using Garber et al. developed model. Based on previous researches, data are collected for variables that have a significant impact on pavement condition. Data for pavement age (AGE, average daily traffic (ADT, and structural number (SN were collected for 44 sections in the network roads. A field survey (destructive test (core test and laboratory test (Marshall Test were used to determine the capacity of structure layer of pavement (SN. The condition index (CI output from a developed model was compared with the PCI output of PAVER 6.5.7 by using statistical analysis test. The developed model overestimates value of CI rather than PCI estimated from PAVER 6.5.7 due to statistical test to a 95% degree of confidence, (R = 0.771 for 44 sections (arterial and collector.

Permeable pavement study (Edison)

Data.gov (United States)

U.S. Environmental Protection Agency — While permeable pavement is increasingly being used to control stormwater runoff, field-based, side-by-side investigations on the effects different pavement types...

Residential mercury contamination in adobe brick homes in Huancavelica, Peru.

Science.gov (United States)

Hagan, Nicole; Robins, Nicholas; Hsu-Kim, Heileen; Halabi, Susan; Espinoza Gonzales, Ruben Dario; Richter, Daniel deB; Vandenberg, John

2013-01-01

This is the first study of adobe brick contamination anywhere in the world. Huancavelica, Peru is the site of historic cinnabar refining and one of the most mercury (Hg) contaminated urban areas in the world. Over 80% of homes in Huancavelica are constructed with adobe bricks made from Hg contaminated soil. In this study we measured total Hg concentrations in adobe brick, dirt floor, surface dust, and air samples from the interior of 60 adobe brick houses located in four neighborhoods. Concentrations of total Hg in adobe bricks, dirt floors, and surface dust ranged from 8.00 to 1070 µg/g, 3.06 to 926 µg/g, and 0.02 to 9.69 µg/wipe, respectively, with statistically significant differences between the four neighborhoods. Concentrations of Hg in adobe brick and dirt floor samples in Huancavelica were orders of magnitude higher than in Ayacucho, a non-mining town in Peru. A strong correlation exists between total Hg concentrations in adobe bricks and dirt floors which confirms that adobe bricks were being made on-site and not purchased from an off-site source. A strong correlation between surface dust and adobe bricks and dirt floors indicates that walls and floors serve as indoor sources of Hg contamination. Elemental Hg vapor concentrations were below detection (adobe bricks, may be a substantial source of residential Hg exposure in silver or gold refining communities where Hg is produced or used for amalgamation in artisanal gold production.

Feasibility of reclaimed asphalt pavement as aggregate in portland cement concrete pavements.

Science.gov (United States)

2013-11-01

This research effort was focused on evaluating the feasibility of using minimally processed reclaimed : asphalt pavement (RAP) as aggregate replacement in concrete pavements. This research demonstrated : that concretes with up to 50 percent of the fi...

MoDOT pavement preservation research program volume III, development of pavement family and treatment performance models.

Science.gov (United States)

2015-10-01

Pavement performance models describe the deterioration behavior of pavements. They are essential in a pavement management : system if the goal is to make more objective, reliable, and cost-effective decisions regarding the timing and nature of paveme...

Lego Bricks and the Octet Rule: Molecular Models for Biochemical Pathways with Plastic, Interlocking Toy Bricks

Science.gov (United States)

Lin, Henry J.; Lehoang, Jennifer; Kwan, Isabel; Baghaee, Anita; Prasad, Priya; Ha-Chen, Stephanie J.; Moss, Tanesha; Woods, Jeremy D.

2018-01-01

The 8 studs on a 2 × 4 Lego brick conveniently represent the outer shell of electrons for carbon, nitrogen, and oxygen atoms. We used Lego bricks to model these atoms, which are then joined together to form molecules by following the Lewis octet rule. A variety of small biological molecules can be modeled in this way, such as most amino acids,…

Natural radioactivity content and radionuclides leachability of bricks containing industrial waste

International Nuclear Information System (INIS)

Zalina Laili; Mohd Zaidi Ibrahim; Nur Azna Mahmud; Muhamat Omar

2012-01-01

A study have been carried out using gamma-ray spectrometric system to determine the natural radioactivity level in bricks made from industrial waste and their associated radiation hazard. Brick-1 and brick-2 contained waste from coal power plant and granite industry, respectively. The leachability of radionuclides from these bricks was also investigated. The activity concentration values of 226 Ra, 228 Ra, 232 Th, and 40 K are 64.25, 63.15, 67.9 and 254.19 Bq kg -1 , respectively in brick-1, and 193, 164.48, 164.63 and 1348.75 Bq kg -1 , respectively in brick-2. The radiation hazard indexes such as radium equivalent activities (Ra eq ), representative level index (I γr ), external hazard index (H ex ) and internal hazard index (H in ) were calculated and compared with the internationally approved values. Results indicate that brick-1 showed less radiological hazard than brick-2. This suggested that brick-1 could be used in building construction without exceeding the proposed criterion level. The leachability of 226 Ra for bricks showed the activity concentration slightly exceeded the limit generally used for industrial wastewater for example 1 BqL -1 . (author)

The Brick Moon

Science.gov (United States)

2004-01-01

Science fiction writers, like Jules Verne in France and Edward Everett Hale in America, had discovered one of the most vital elements in the formula for space travel-a fertile imagination. The first known proposal for a marned-satellite appears in a story by Hale entitled 'The Brick Moon' published in 1899. The story involved a group of young Bostonians who planned to put an artificial satellite into polar orbit for sailors to use to determine longitude accurately and easily. They planned to send a brick satellite into orbit because the satellite would have to withstand fire very well. The Satellite's 37 inhabitants signaled the Earth in morse code by jumping up and down on the outside of the satellite.

Urban-environmental study from the Juarez municipality brick factories

Directory of Open Access Journals (Sweden)

María de Lourdes Romo Aguilar

2004-01-01

Full Text Available This paper seeks to evaluate the current situation of the traditional and ecological brick kilns in Juarez. The evaluation is addressed in both the environmental and socio-economic context. The brick production belongs to the informal economic sector without any regulatory scheme and without taxation. Its very low technology has serious impacts on the binational environment of the Paso del Norte region, through the highly polluted emissions to the atmosphere. However, the social and economic context of people working in this industry does not allow important changes, thus, making difficult any initiative for the brick kilns improvements and relocation. The main information source was a very concise survey applied to whole universe of brick makers. Data survey was registered in a Geographic Information System (GIS environment allowing us the analysis of the brick kilns in a spatial context. Finally, this document presents a descriptive profile of the brick kilns production and for the brickmakers.

Sasol Coal`s `better brick` for colliery ventilation walls

Energy Technology Data Exchange (ETDEWEB)

NONE

1993-12-01

Sasol coal has developed a better brick for construction of ventilation walls underground. It has proven to be a speedy and cost-saving alternative to the standard concrete block used for the purpose. The brick has an interlocking design ensuring that it is laid correctly. Unlike the conventional concrete block, the ventilation walls built for the new brick do not have to be plastered to achieve airtightness. The skills required to build such walls are minimal as the design of the brick makes it virtually impossible to lay it badly or unevenly - further facilitated by the absence of mortar. While introducing the new method Sasol Coal took the opportunity to introduce a purpose-made trailer for transporting the bricks, with the trailer doubling as a building platform on site. This has further contributed to the efficiency and speed of the operation. It has also reduced to a minimum the number of times the bricks are handled, thus cutting down on breakages. 1 fig.

Impact of pavement conditions on crash severity.

Science.gov (United States)

Li, Yingfeng; Liu, Chunxiao; Ding, Liang

2013-10-01

Pavement condition has been known as a key factor related to ride quality, but it is less clear how exactly pavement conditions are related to traffic crashes. The researchers used Geographic Information System (GIS) to link Texas Department of Transportation (TxDOT) Crash Record Information System (CRIS) data and Pavement Management Information System (PMIS) data, which provided an opportunity to examine the impact of pavement conditions on traffic crashes in depth. The study analyzed the correlation between several key pavement condition ratings or scores and crash severity based on a large number of crashes in Texas between 2008 and 2009. The results in general suggested that poor pavement condition scores and ratings were associated with proportionally more severe crashes, but very poor pavement conditions were actually associated with less severe crashes. Very good pavement conditions might induce speeding behaviors and therefore could have caused more severe crashes, especially on non-freeway arterials and during favorable driving conditions. In addition, the results showed that the effects of pavement conditions on crash severity were more evident for passenger vehicles than for commercial vehicles. These results provide insights on how pavement conditions may have contributed to crashes, which may be valuable for safety improvement during pavement design and maintenance. Readers should notice that, although the study found statistically significant effects of pavement variables on crash severity, the effects were rather minor in reality as suggested by frequency analyses. Copyright © 2013 Elsevier Ltd. All rights reserved.

Evaluation of airfield pavement evenness

Science.gov (United States)

Pietruszewski, Paweł; Poświata, Adam; Wesołowski, Mariusz

2018-05-01

The evenness of airfield pavements is one of the basic operating parameters, which characterize them. The evenness determines not only comfort of traffic along an airfield pavement, but also influences the size of dynamic effect on the pavement, hence, the safety of air operations. In addition, the evenness condition changing as a result of dynamic loads, adverse weather conditions or inappropriate airfield pavement construction technology, lead to deviations from the desired condition in the form of longitudinal and transverse unevenness. As a result, systematic and correct performance of tests is a very significant and required factor impacting the improvement of traffic safety on airfield pavements. If the data obtained through the measurements are not sufficiently reliable, they may consequently lead to making incorrect decisions, which can ultimately impact the safety of air operations.

Development of improved bricks (LM) and use of new technologies for ecological bricks (LE) elaboration

OpenAIRE

Zuñiga-Suárez, Alonso; Hernández-Olivares, Francisco; Fernández-Martínez, Francisco; Zuñiga, Berenice; Sánchez, Luis; Paladines, Juan; Mercader-Moyano, Pilar (Coordinador)

2017-01-01

Brick is a material that has been widely used in construction sector, however, it has not received the necessary attention in order to improve its performance, which has resulted a general lack of knowledge about its manufacturing processes such as: clay mines over-exploitation, ignorance of mixtures dosages and greenhouse gas emissions from wood burning. This research therefore aims to find a suitable mixture to produce improved bricks (LM) by analysing its mechanical prope...

Analysis of Brick Masonry Wall using Applied Element Method

Science.gov (United States)

Lincy Christy, D.; Madhavan Pillai, T. M.; Nagarajan, Praveen

2018-03-01

The Applied Element Method (AEM) is a versatile tool for structural analysis. Analysis is done by discretising the structure as in the case of Finite Element Method (FEM). In AEM, elements are connected by a set of normal and shear springs instead of nodes. AEM is extensively used for the analysis of brittle materials. Brick masonry wall can be effectively analyzed in the frame of AEM. The composite nature of masonry wall can be easily modelled using springs. The brick springs and mortar springs are assumed to be connected in series. The brick masonry wall is analyzed and failure load is determined for different loading cases. The results were used to find the best aspect ratio of brick to strengthen brick masonry wall.

Properties of fired clay brick incorporating with sewage sludge waste

Science.gov (United States)

Kadir, Aeslina Abdul; Salim, Nurul Salhana Abdul; Sarani, Noor Amira; Rahmat, Nur Aqma Izurin; Abdullah, Mohd Mustafa Al Bakri

2017-09-01

The production of sludge in wastewater treatment plant is about to increase every year and most of the sludge was directly disposed to landfill. In addition, the constraint to treat sludge is very high in cost and time- consuming could be disadvantages to the responsible parties. Therefore, this research was conducted to utilize sludge produced from the wastewater treatment plant into fired clay brick as one of the alternatives of disposal method. In this study, the research attempt to incorporate sewage sludge waste (SSW) into fired clay brick. The sewage sludge brick (SSB) mixtures were incorporated with 0%, 1%, 5%, 10%, and 20% of SSW. The manufactured bricks were fired at 1050°C with heating rate of 1°C/min. Physical and mechanical properties test were conducted such as shrinkage, density, water absorption and compressive strength. As the conclusion, brick with utilization 5% of SSW is acceptable to produce good quality of brick. This study shows by using SSW in fired clay brick could be an alternative method to dispose of the SSW and also could act as a replacement material for brick manufacturing with appropriate mix and design.

Evaluation of various hot mix asphalt pavement thicknesses over rubblized concrete pavement.

Science.gov (United States)

2011-07-01

In 1999, the Wisconsin DOT constructed two test sections as part of a rubblized PCC pavement project on I-39 to evaluate whether : increased HMA thickness could extend the pavement system's service life. Design thicknesses of the control and test sec...

Pavement Performance : Approaches Using Predictive Analytics

Science.gov (United States)

2018-03-23

Acceptable pavement condition is paramount to road safety. Using predictive analytics techniques, this project attempted to develop models that provide an assessment of pavement condition based on an array of indictors that include pavement distress,...

Surface dating of bricks, an application of luminescence techniques

Science.gov (United States)

Galli, Anna; Martini, Marco; Maspero, Francesco; Panzeri, Laura; Sibilia, Emanuela

2014-05-01

Luminescence techniques are a powerful tool to date archaeological ceramic materials and geological sediments. Thermoluminescence (TL) is widely used for bricks dating to reconstruct the chronology of urban complexes and the development of human cultures. However, it can sometimes be inconclusive, since TL assesses the firing period of bricks, which can be reused, even several centuries later. This problem can be circumvented using a dating technique based on a resetting event different from the last heating. OSL (Optically Stimulated Luminescence) exploits the last light exposition of the brick surface, which resets the light-sensitive electron traps until the surface is definitely shielded by mortar and superimposed bricks. This advanced application (surface dating) has been successfully attempted on rocks, marble and stone artifacts, but not yet on bricks. A recent conservation campaign at the Certosa di Pavia gave the opportunity to sample some bricks belonging to a XVII century collapsed wall, still tied to their mortars. This was an advantageous condition to test this technique, comparing the dating results with precise historical data. This attempt gave satisfactory results, allowing to identify bricks surely reused and to fully confirm that the edification of the perimetral wall occurred at the end of XVII century.

The influence of water saturation on mechanical properties of ceramic bricks – tests on 19th- century and contemporary bricks

Directory of Open Access Journals (Sweden)

Matysek, P.

2016-09-01

Full Text Available The paper presents test results concerning ceramic bricks produced in 1880’s. Bricks were obtained from a building erected as part of Archduke Rudolf barracks in Krakow. The tests helped to specify changes in brick compressive strength and hardness, caused by water saturation in the ceramic material. For comparison purposes, tests were also carried out on contemporary bricks. Tests showed that mechanical properties of the ceramic bricks in the water saturation state were worse than in the dry state. The impact of strong brick moisture on changes of mechanical parameters is essential in terms of safety assessment for brick structures.En el artículo se presentan los resultados del estudio de los ladrillos cerámicos producidos en los años 80 del siglo XIX. Los ladrillos se obtuvieron del edificio que forma parte de un conjunto de cuarteles del archiduque Rudolfo en Cracovia en Polonia. En los estudios se han determinado los cambios de la resistencia a la compresión y la dureza de los ladrillos, por efecto de la saturación de agua del material cerámico. A efectos comparativos, se han realizado también estudios de ladrillos producidos en la actualidad. Se ha comprobado que la saturación de agua de los ladrillos cerámicos lleva consigo una considerable disminución de las propiedades mecánicas. Por lo tanto, el impacto de la alta humedad de los ladrillos sobre el cambio de las propiedades mecánicas constituye un factor significativo en la evaluación de la seguridad en las construcciones de ladrillo.

Prevalence of Brick Tea-Type Fluorosis in the Tibet Autonomous Region.

Science.gov (United States)

Fan, Zhipeng; Gao, Yanhui; Wang, Wei; Gong, Hongqiang; Guo, Min; Zhao, Shengcheng; Liu, Xuehui; Yu, Bing; Sun, Dianjun

2016-01-01

The prevalence of brick tea-type fluorosis is high in Tibet because of the habit of drinking brick tea in this region. Brick tea-type fluorosis has become an urgent public health problem in China. A cross-sectional survey was conducted to investigate prevalence of brick tea-type fluorosis in all districts of Tibet using a stratified cluster sampling method. Dental fluorosis in children aged 8-12 years and clinical skeletal fluorosis in adults were diagnosed according to the national criteria. A total of 423 children and 1320 adults participated in the study. Samples of drinking water, brick tea, brick tea infusion (or buttered tea), and urine were collected and measured for fluoride concentrations by the fluoride ion selective electrode method. The fluoride level in all but one of the brick tea samples was above the national standard. The average daily fluoride intake from drinking brick tea in all seven districts in Tibet was much higher than the national standard. The prevalence of dental fluorosis was 33.57%, and the prevalence of clinical skeletal fluorosis was 46.06%. The average daily fluoride intake from drinking brick tea (r = 0.292, P < 0.05), urine fluoride concentrations in children (r = 0.134, P < 0.05), urine fluoride concentrations in adults (r = 0.162, P < 0.05), and altitude (r = 0.276, P < 0.05) were positively correlated with the prevalence of brick tea-type fluorosis. Herdsmen had the highest fluoride exposure and the most severe skeletal fluorosis. Brick tea-type fluorosis in Tibet is more serious than in other parts of China. The altitude and occupational factors are important risk factors for brick tea-type fluorosis.

An Experimental Investigation of Mechanical Properties in Clay Brick Masonry by Partial Replacement of Fine Aggregate with Clay Brick Waste

Science.gov (United States)

Kumavat, Hemraj Ramdas

2016-09-01

The compressive stress-strain behavior and mechanical properties of clay brick masonry and its constituents clay bricks and mortar, have been studied by several laboratory tests. Using linear regression analysis, a analytical model has been proposed for obtaining the stress-strain curves for masonry that can be used in the analysis and design procedures. The model requires only the compressive strengths of bricks and mortar as input data, which can be easily obtained experimentally. Development of analytical model from the obtained experimental results of Young's modulus and compressive strength. Simple relationships have been identified for obtaining the modulus of elasticity of bricks, mortar, and masonry from their corresponding compressive strengths. It was observed that the proposed analytical model clearly demonstrates a reasonably good prediction of the stress-strain curves when compared with the experimental curves.

Concrete pavement joint deterioration.

Science.gov (United States)

2015-12-01

Concrete pavements are an important part of our national infrastructure. In recent years the relatively small number of reported joints deteriorating prematurely in concrete pavements around Indiana has increased. Changes over the past 45 years in IN...

Verification of mechanistic-empirical design models for flexible pavements through accelerated pavement testing.

Science.gov (United States)

2014-08-01

The Midwest States Accelerated Pavement Testing Pooled Fund Program, financed by the highway : departments of Kansas, Iowa, and Missouri, has supported an accelerated pavement testing (APT) project to : validate several models incorporated in the NCH...

Inverted base pavements: construction and performance

KAUST Repository

Papadopoulos, Efthymios

2017-05-11

Inverted base pavements involve a well-compacted granular aggregate base built between a thin asphalt concrete layer and a cement-treated base. Inverted base pavements can be constructed using conventional equipment and procedures but require proper quality control. This study reviews the extensive South African experience and case histories in the USA. Accumulating evidence suggests that inverted base pavements are a viable alternative and can outperform conventional pavements at a lower cost. Inverted base pavements rely on the complementary interaction between layers. The cement-treated base provides a stiff foundation for efficient compaction and constrains the deformation of the stress-sensitive granular aggregate base. The thin asphalt surface layer deforms as a membrane and develops low tensile stress. Additional large-scale field tests should be conducted to assess the performance of inverted base pavement designs in a wide range of conditions relevant to the USA.

Prevalence of Brick Tea-Type Fluorosis in the Tibet Autonomous Region

Directory of Open Access Journals (Sweden)

Zhipeng Fan

2016-02-01

Full Text Available Background: The prevalence of brick tea-type fluorosis is high in Tibet because of the habit of drinking brick tea in this region. Brick tea-type fluorosis has become an urgent public health problem in China. Methods: A cross-sectional survey was conducted to investigate prevalence of brick tea-type fluorosis in all districts of Tibet using a stratified cluster sampling method. Dental fluorosis in children aged 8–12 years and clinical skeletal fluorosis in adults were diagnosed according to the national criteria. A total of 423 children and 1320 adults participated in the study. Samples of drinking water, brick tea, brick tea infusion (or buttered tea, and urine were collected and measured for fluoride concentrations by the fluoride ion selective electrode method. Results: The fluoride level in all but one of the brick tea samples was above the national standard. The average daily fluoride intake from drinking brick tea in all seven districts in Tibet was much higher than the national standard. The prevalence of dental fluorosis was 33.57%, and the prevalence of clinical skeletal fluorosis was 46.06%. The average daily fluoride intake from drinking brick tea (r = 0.292, P < 0.05, urine fluoride concentrations in children (r = 0.134, P < 0.05, urine fluoride concentrations in adults (r = 0.162, P < 0.05, and altitude (r = 0.276, P < 0.05 were positively correlated with the prevalence of brick tea-type fluorosis. Herdsmen had the highest fluoride exposure and the most severe skeletal fluorosis. Conclusions: Brick tea-type fluorosis in Tibet is more serious than in other parts of China. The altitude and occupational factors are important risk factors for brick tea-type fluorosis.

A new clamp method for firing bricks | Obeng | Journal of Applied ...

African Journals Online (AJOL)

A new clamp method for firing bricks. ... Journal of Applied Science and Technology ... To overcome this operational deficiencies, a new method of firing bricks that uses brick clamp technique that incorporates a clamp wall of 60 cm thickness, a six tier approach of sealing the top of the clamp (by combination of green bricks) ...

Pavement Subgrade Performance Study

DEFF Research Database (Denmark)

Zhang, Wei; Ullidtz, Per; Macdonald, Robin

1998-01-01

The report describes the second test in the Danish Road Testing Machine (RTM) under the International Pavement Subgrade Performance Study. Pavement response was measured in different layers, and compared to different theroretical values. Performance in terms of plastic strains, rutting...

Residential mercury contamination in adobe brick homes in Huancavelica, Peru.

Directory of Open Access Journals (Sweden)

Nicole Hagan

Full Text Available This is the first study of adobe brick contamination anywhere in the world. Huancavelica, Peru is the site of historic cinnabar refining and one of the most mercury (Hg contaminated urban areas in the world. Over 80% of homes in Huancavelica are constructed with adobe bricks made from Hg contaminated soil. In this study we measured total Hg concentrations in adobe brick, dirt floor, surface dust, and air samples from the interior of 60 adobe brick houses located in four neighborhoods. Concentrations of total Hg in adobe bricks, dirt floors, and surface dust ranged from 8.00 to 1070 µg/g, 3.06 to 926 µg/g, and 0.02 to 9.69 µg/wipe, respectively, with statistically significant differences between the four neighborhoods. Concentrations of Hg in adobe brick and dirt floor samples in Huancavelica were orders of magnitude higher than in Ayacucho, a non-mining town in Peru. A strong correlation exists between total Hg concentrations in adobe bricks and dirt floors which confirms that adobe bricks were being made on-site and not purchased from an off-site source. A strong correlation between surface dust and adobe bricks and dirt floors indicates that walls and floors serve as indoor sources of Hg contamination. Elemental Hg vapor concentrations were below detection (<0.5 µg/m(3 in most homes; however in homes with detectable levels, concentrations up to 5.1 µg/m(3 were observed. No statistically significant differences in Hg vapor measurements were observed between neighborhoods. This study demonstrates that building materials used widely in developing communities, such as adobe bricks, may be a substantial source of residential Hg exposure in silver or gold refining communities where Hg is produced or used for amalgamation in artisanal gold production.

Pavement Snow Melting

Energy Technology Data Exchange (ETDEWEB)

Lund, John W.

2005-01-01

The design of pavement snow melting systems is presented based on criteria established by ASHRAE. The heating requirements depends on rate of snow fall, air temperature, relative humidity and wind velocity. Piping materials are either metal or plastic, however, due to corrosion problems, cross-linked polyethylene pipe is now generally used instead of iron. Geothermal energy is supplied to systems through the use of heat pipes, directly from circulating pipes, through a heat exchanger or by allowing water to flow directly over the pavement, by using solar thermal storage. Examples of systems in New Jersey, Wyoming, Virginia, Japan, Argentina, Switzerland and Oregon are presented. Key words: pavement snow melting, geothermal heating, heat pipes, solar storage, Wyoming, Virginia, Japan, Argentina, Klamath Falls.

Flexible pavement rehabilitation design based on pavement service life time span left

OpenAIRE

Gamelyak, I.; Shevchuk, V.

2005-01-01

The design of flexible pavement rehabilitation is analysed in terms of durability-cost. A notion of the remaining service life span is described. the model of rehabilitation strategy selection is presented for both design project and operation stages. the results can be used in the pavement management system.

Comparison of accelerated pavement test results with long term pavement behaviour and performance

CSIR Research Space (South Africa)

Jooste, FJ

1997-08-01

Full Text Available The aim of this study was to investigate the following:how accelerated pavement testing predictions compare with actual road behaviour and performance the relative influences of load and environmental factors on pavement deterioration and how well...

Advanced Pavement Design: Finite Element Modeling for Rigid Pavement Joints, Report II: Model Development

National Research Council Canada - National Science Library

Hammons, Michael

1998-01-01

.... The objective of this research was to obtain data on the response of the ng'id pavement slab-joint-foundation system by conducting laboratory-scale experiments on jointed rigid pavement models...

"Method, system and storage medium for generating virtual brick models"

DEFF Research Database (Denmark)

2009-01-01

An exemplary embodiment is a method for generating a virtual brick model. The virtual brick models are generated by users and uploaded to a centralized host system. Users can build virtual models themselves or download and edit another user's virtual brick models while retaining the identity...

Possible weathering of the brick matrix when exposed to water

DEFF Research Database (Denmark)

Rörig-Dalgaard, Inge

2014-01-01

The main reasons for deterioration of bricks are frost, crystallization pressure and chemical exposure. Despite of this the effect of chemical exposure is limited clarified. Depending on the brick type the original pH of bricks are 9-10. Though bricks can to subjected to water in shape of acid rain...... with different well-defined pH values are examined to investigate the long term effect of acid rain or other reasons causing pH changes to bricks (as e.g. electrokinetic treatment). Through capillary suction, macro pictures from the exposed surfaces, measurement of the pH and electrical conductivity it seemed...... that there is a consistence with the literature of the glassy phase describing ion exchange at low pH and break down of the lattice in the glassy structure at high pH. At present remains examination of polished sections with SEM/EDX, measurements of each of the ionic contents in the brick matrix and new series with a longer...

Development of Pavement Condition Index Model Using PAVER 6.5.7 for Flexible Pavement Urban Roads in Kerbala City

Directory of Open Access Journals (Sweden)

Hussein Ali Ewadh

2017-08-01

Full Text Available The pavement condition index (PCI is an important factor indicating pavement condition of roads. The pavement is one of the basic parts of the road infrastructure. Accordingly the aim of this paper is to develop a pavement condition index model using PAVER 6.5.7 for a flexible pavement urban roads in the Kerbala city center. The development model is depending on the PCI value of 109 sample sections having 57.8 km length, Data collected for pavement distress (type, dimension, and severity were used to find PCI. The filtering and outlier analysis was done by using a polynomial (fourth-degree constrained least squared for statistical process. These processes were done by (PAVER 6.5.7 software. The result of the prediction model of PCI shows that it is valid to be used in the prediction of the condition of pavement for the same family type

[Study on Hollow Brick Wall's Surface Temperature with Infrared Thermal Imaging Method].

Science.gov (United States)

Tang, Ming-fang; Yin, Yi-hua

2015-05-01

To address the characteristic of uneven surface temperature of hollow brick wall, the present research adopts soft wares of both ThermaCAM P20 and ThermaCAM Reporter to test the application of infrared thermal image technique in measuring surface temperature of hollow brick wall, and further analyzes the thermal characteristics of hollow brick wall, and building material's impact on surface temperature distribution including hollow brick, masonry mortar, and so on. The research selects the construction site of a three-story-high residential, carries out the heat transfer experiment, and further examines the exterior wall constructed by 3 different hollow bricks including sintering shale hollow brick, masonry mortar and brick masonry. Infrared thermal image maps are collected, including 3 kinds of sintering shale hollow brick walls under indoor heating in winter; and temperature data of wall surface, and uniformity and frequency distribution are also collected for comparative analysis between 2 hollow bricks and 2 kinds of mortar masonry. The results show that improving heat preservation of hollow brick aid masonry mortar can effectively improve inner wall surface temperature and indoor thermal environment; non-uniformity of surface temperature decreases from 0. 6 to 0. 4 °C , and surface temperature frequency distribution changes from the asymmetric distribution into a normal distribution under the condition that energy-saving sintering shale hollow brick wall is constructed by thermal mortar replacing cement mortar masonry; frequency of average temperature increases as uniformity of surface temperature increases. This research provides a certain basis for promotion and optimization of hollow brick wall's thermal function.

Electrokinetic removal of salt from brick masonry

DEFF Research Database (Denmark)

Ottosen, Lisbeth M.; Pedersen, Anne Juul; Rörig-Dalgaard, Inge

2006-01-01

A method to effectively remove salts from masonry is lacking. The present study aims at determining the removal efficiency of salts from bricks in an applied low current electric DC field. At first an investigation on removal of NaCl and Na(NO3)2 from spiked bricks in laboratory scale was conducted...

Assessment of highway pavements using GPR

Science.gov (United States)

Plati, Christina; Loizos, Andreas

2015-04-01

Highway infrastructure is a prerequisite for a functioning economy and social life. Highways, often prone to congestion and disruption, are one of the aspects of a modern transport network that require maximum efficiency if an integrated transport network, and sustainable mobility, is to be achieved. Assessing the condition of highway structures, to plan subsequent maintenance, is essential to allow the long-term functioning of a road network. Optimizing the methods used for such assessment will lead to better information being obtained about the road and underlying ground conditions. The condition of highway structures will be affected by a number of factors, including the properties of the highway pavement, the supporting sub-base and the subgrade (natural ground), and the ability to obtain good information about the entire road structure, from pavement to subgrade, allows appropriate maintenance programs to be planned. The maintenance of highway pavements causes considerable cost and in many cases obstruction to traffic flow. In this situation, methods that provide information on the present condition of pavement structure non-destructively and economically are of great interest. It has been shown that Ground-Penetrating-Radar (GPR), which is a Non Destructive Technique (NDT), can deliver information that is useful for the planning of pavement maintenance activities. More specifically GPR is used by pavement engineers in order to determine physical properties and characteristics of the pavement structure, information that is valuable for the assessment of pavement condition. This work gives an overview on the practical application of GPR using examples from highway asphalt pavements monitoring. The presented individual applications of GPR pavement diagnostics concern structure homogeneity, thickness of pavement layers, dielectric properties of asphalt materials etc. It is worthwhile mentioning that a number of applications are standard procedures, either

The utilization of brick walls for resisting earthquake in building technology

Science.gov (United States)

Tarigan, J.; Benedicta, C.

2018-03-01

Many structures in Indonesia use reinforced concrete frames with brick walls as their infill. Commonly, the engineers consider brick walls as the partitions and count them as the non-structural elements in the structure design. However, brick walls are capable of resisting earthquake by yielding high stiffness to the structure in case the brick walls are integrated well with the frames. It will reduce the non-structural destructions that happen to structures which is one of the most frequently impacts in the earthquake. This paper will take the effects of applying brick walls as the structural elements up by comparing it with the structure using brick walls as the partitions. The modeling of the brick walls uses the equivalent spectrum method meanwhile the seismic analysis uses the respon spectrum method. The utilization of brick walls can cause the decrement of the natural period to 42%. It also reduce the structure displacements to 53% in X-direction and 67% in Y-direction and the story drifts to 57% in X-direction and 71% in Y-direction. Otherwise, it causes the increment of the base shear only up to 3% in X-direction and 7% in Y-direction.

Thermal Performance of the Storage Brick Containing Microencapsulated PCM

International Nuclear Information System (INIS)

Lee, Dong Gyu

1998-02-01

The utilization of microencapsulated phase change materials(PCMs) provides several advantages over conventional PCM application. The heat storage system, as well as heat recovery system, can be built to a smaller size than the normal systems for a given thermal cycling capacity. This microencapsulated PCM technique has not yet been commercialized, however. In this work sodium acetate trihydrate(CH 3 COONa · 3H 2 O) was selected for the PCM and was encapsulated. This microencapsulated PCM was mixed with cement mortar for utilization as a floor heating system. In this experiment performed here the main purpose was to investigate the thermal performance of a storage brick with microencapsulated PCM concentration. The thermal performance of this storage brick is dependent on PCM concentration, flow rate and cooling temperature of the heat transfer fluid, etc. The results showed that cycle time was shortened as the PCM content was increased and as the mass flow rate was increased. The same effect was obtained when the cooling temperature was decreased. For each thermal storage brick the overall heat transfer coefficient(U-value) was constant for a 0% brick, but was increased with time for the bricks containing microencapsulated PCM. For the same mass flow rate, as the cooling temperature decreased, the amount of heat withdrawn increased, and in particular a critical cooling temperature was found for each thermal storage brick. The average effectiveness of each thermal storage brick was found to be approximately 48%, 51% and 58% respectively

Optimization and standardization of pavement management processes.

Science.gov (United States)

2004-08-01

This report addresses issues related to optimization and standardization of current pavement management processes in Kentucky. Historical pavement management records were analyzed, which indicates that standardization is necessary in future pavement ...

MoDOT pavement preservation research program volume IV, pavement evaluation tools-data collection methods.

Science.gov (United States)

2015-10-01

The overarching goal of the MoDOT Pavement Preservation Research Program, Task 3: Pavement Evaluation Tools Data : Collection Methods was to identify and evaluate methods to rapidly obtain network-level and project-level information relevant to :...

Analysis of the major chemical compositions in Fuzhuan brick-tea ...

African Journals Online (AJOL)

Fuzhuan brick-tea, a fungal-fermented tea, is commonly consumed in northwest China; in places such as Sinkiang and Tibet and is thought to be helpful in digestion. To better understand Fuzhuan brick-tea and its function on digestion, the Fuzhuan brick-tea's chemical compounds were surveyed at pivotal process phases, ...

Reconsideration of tyre-pavement input parameters for the structural design of flexible pavements

CSIR Research Space (South Africa)

De Beer, Morris

2006-08-01

Full Text Available of modern truck tyres. Tyre-pavement contact stress measurements were carried out on a busy national road (N3) in South Africa from the port of Durban to the inland province of Gauteng. The three-dimensional tyre-pavement contact stress regimes of 45 227...

Enhancing pavement performance prediction models for the Illinois Tollway System

Directory of Open Access Journals (Sweden)

Laxmikanth Premkumar

2016-01-01

Full Text Available Accurate pavement performance prediction represents an important role in prioritizing future maintenance and rehabilitation needs, and predicting future pavement condition in a pavement management system. The Illinois State Toll Highway Authority (Tollway with over 2000 lane miles of pavement utilizes the condition rating survey (CRS methodology to rate pavement performance. Pavement performance models developed in the past for the Illinois Department of Transportation (IDOT are used by the Tollway to predict the future condition of its network. The model projects future CRS ratings based on pavement type, thickness, traffic, pavement age and current CRS rating. However, with time and inclusion of newer pavement types there was a need to calibrate the existing pavement performance models, as well as, develop models for newer pavement types.This study presents the results of calibrating the existing models, and developing new models for the various pavement types in the Illinois Tollway network. The predicted future condition of the pavements is used in estimating its remaining service life to failure, which is of immediate use in recommending future maintenance and rehabilitation requirements for the network. Keywords: Pavement performance models, Remaining life, Pavement management

Pavement noise measurements in Poland

Science.gov (United States)

Zofka, Ewa; Zofka, Adam; Mechowski, Tomasz

2017-09-01

The objective of this study is to investigate the feasibility of the On-Board Sound Intensity (OBSI) system to measure tire-pavement noise in Poland. In general, sources of noise emitted by the modern vehicles are the propulsion noise, aerodynamic resistance and noise generated at the tire-pavement interface. In order to capture tire-pavement noise, the OBSI system uses a noise intensity probe installed in the close proximity of that interface. In this study, OBSI measurements were performed at different types of pavement surfaces such as stone mastic asphalt (SMA), regular asphalt concrete (HMA) as well as Portland cement concrete (PCC). The influence of several necessary OBSI measurement conditions were recognized as: testing speed, air temperature, tire pressure and tire type. The results of this study demonstrate that the OBSI system is a viable and robust tool that can be used for the quality evaluation of newly built asphalt pavements in Poland. It can be also applied to generate reliable input parameters for the noise propagation models that are used to assess the environmental impact of new and existing highway corridors.

Biosusceptibility of historical bricks from the Bač fortress: part I

Directory of Open Access Journals (Sweden)

Vidaković Ana M.

2013-01-01

Full Text Available The significance of the conservation of cultural heritage objects has led to a greater interest in the appearance of biocorrosion. The aim of this paper is to point out the correlation between the growth of fungi isolated from the fortress of Bač and the contact angle value of the bricks from the fortress in order to determine the brick susceptibility to biodegradation. Three types of bricks (red, yellow and roan and three isolates of Penicillium spp., as well as one isolate of Cladosporium sp., were used during the experiments. A suspension of fungi in soil extract solution was inflicted on the surface of the bricks and then the samples were incubated. The study showed that the red bricks with cut surface and the roan bricks with broken surface are the most susceptible to the biocorrosion process. Based on the obtained results, Cladosporium sp. can be considered as the most important biodeteriogenic factor on the bricks built in the walls of the Bač fortress. [Projekat Ministarstva nauke Republike Srbije, br. III45008

A guide for local agency pavement managers

Science.gov (United States)

1994-12-01

The purpose of this guide is to provide Washington's local agencies with a practical document that will assist pavement managers in understanding the pavement management process and the steps necessary to implement their own pavement management syste...

Leachability of fired clay brick incorporating with sewage sludge waste

Science.gov (United States)

Kadir, Aeslina Abdul; Salim, Nurul Salhana Abdul; Sarani, Noor Amira; Rahmat, Nur Aqma Izurin; Abdullah, Mohd Mustafa Al Bakri

2017-09-01

Sewage sludge is sewerage from wastewater treatment plants that generates millions tons of sludge ever year. Regarding this activity, it causes lack management of waste which is harmful to the surrounding conditions. Therefore, this study is focuses on the incorporation of sewage sludge waste into fired clay brick to provide an option of disposal method, producing adequate quality of brick as well as limiting the heavy metal leachability to the environment. Sewage sludge brick (SSB) mixtures were incorporated with 0%, 1%, 5%, 10%, 20% and 30% of sewage sludge waste (SSW). Heavy metals of crushed SSB were determined by using Toxicity Characteristic Leaching Procedure (TCLP) according to Method 1311 of United State Environment Protection Agency (USEPA) standard. From the results obtained, up to 20% of SSW could be incorporated into fired clay brick and comply with the USEPA standard. Therefore, this study revealed that by incorporating SSW into fired clay brick it could be an alternative method to dispose the SSW and also could act as a replacement material for brick manufacturing with appropriate mix and design.

Calibration of full-scale accelerated pavement testing data using long-term pavement performance data

CSIR Research Space (South Africa)

VdM Steyn, WJ

2012-09-01

Full Text Available Accelerated Pavement Testing (APT) has always been conducted with the objective of improving the understanding of real pavements under real traffic and environmental conditions. While APT provides an accelerated view of some of the major structural...

Integration and Evaluation of Automated Pavement Distress Data in INDOT’s Pavement Management System

Science.gov (United States)

2017-05-01

This study was in two parts. The first part established and demonstrated a framework for pavement data integration. This is critical for fulfilling QC/QA needs of INDOTs pavement management system, because the precision of the physical location re...

Long Life Pavements; Firmes de larga duracion

Energy Technology Data Exchange (ETDEWEB)

Mateos Moreno, A.; Marron Fernandez, J. O.; Perez Ayuso, J.

2009-07-01

The existence of long-life pavements is not new; they have been built in Europe and the United States for decades. In fact, the concept arises from the observation of in-service roads; it was verified how particular pavements, initially designed for a 20-year service life, did not seem to have reduced the bearing capacity along the time, and its maintenance necessities had been exclusively focused on the wearing course. The base idea of long-life pavements is the existence of a fatigue threshold below which the damage produced by each load application is, in practice, zero or below the healing potential of the asphalt mix. The use practice of long-life pavements design considers a pavements constituted by three asphalt layers, each one with a very specific role: a wearing course that provides with the surface characteristics, an intermediate course that provides with most of the structural capacity and a base course that provides with the fatigue resistance. Furthermore, one of the particularities is the design against specific distress mechanisms. Maintenance strategy also presents specific particularities for long-life pavements. It is essentially focused on the detection of surface deterioration, and the appropriate and timely repair, before the damage extends beyond the wearing course, putting into risk the structural integrity of the pavement. Nowadays, this new way to conceive the design, the construction and the maintenance of road pavements, constitutes one of the main challenges for pavement engineering worldwide. (Author) 5 refs.

Analysis and design optimization of flexible pavement

Energy Technology Data Exchange (ETDEWEB)

Mamlouk, M.S.; Zaniewski, J.P.; He, W.

2000-04-01

A project-level optimization approach was developed to minimize total pavement cost within an analysis period. Using this approach, the designer is able to select the optimum initial pavement thickness, overlay thickness, and overlay timing. The model in this approach is capable of predicting both pavement performance and condition in terms of roughness, fatigue cracking, and rutting. The developed model combines the American Association of State Highway and Transportation Officials (AASHTO) design procedure and the mechanistic multilayer elastic solution. The Optimization for Pavement Analysis (OPA) computer program was developed using the prescribed approach. The OPA program incorporates the AASHTO equations, the multilayer elastic system ELSYM5 model, and the nonlinear dynamic programming optimization technique. The program is PC-based and can run in either a Windows 3.1 or a Windows 95 environment. Using the OPA program, a typical pavement section was analyzed under different traffic volumes and material properties. The optimum design strategy that produces the minimum total pavement cost in each case was determined. The initial construction cost, overlay cost, highway user cost, and total pavement cost were also calculated. The methodology developed during this research should lead to more cost-effective pavements for agencies adopting the recommended analysis methods.

Training development for pavement preservation.

Science.gov (United States)

2013-05-01

This research project strives to help the Iowa Department of Transportation (DOT) fully achieve the full benefits of pavement : preservation through training on proper selection, design, and application of pavement preservation treatments. In some ca...

Alternative pavements for snowmobile crossings.

Science.gov (United States)

2009-09-01

Excessive highway pavement wear from snowmobile traffic is a maintenance problem for the New Hampshire Department of : Transportation. The snowmobiles and trail grooming equipment scar and erode the pavement surfaces, eventually creating wide ruts ac...

Identification of Pavement Distress Types and Pavement Condition Evaluation Based on Network Level Inspection for Jazan City Road Network

Directory of Open Access Journals (Sweden)

M Mubaraki

2014-06-01

Full Text Available The first step in establishing a pavement management system (PMS is road network identification. An important feature of a PMS is the ability to determine the current condition of a road network and predict its future condition. Pavement condition evaluation may involve structure, roughness, surface distress, and safety evaluation. In this study, a pavement distress condition rating procedure was used to achieve the objectives of this study. The main objectives of this study were to identify the common types of distress that exist on the Jazan road network (JRN, either on main roads or secondary roads, and to evaluate the pavement condition based on network level inspection. The study was conducted by collecting pavement distress types from 227 sample units on main roads and 500 sample units from secondary roads. Data were examined through analysis of common types of distress identified in both main and secondary roads. Through these data, pavement condition index (PCI for each sample unit was then calculated. Through these calculations, average PCIs for the main and secondary roads were determined. Results indicated that the most common pavement distress types on main roads were patching and utility cut patching, longitudinal and transverse cracking, polished aggregate, weathering and raveling, and alligator cracking. The most common pavement distress types on secondary roads were weathering and raveling, patching and utility cut patching, longitudinal and transverse cracking, potholes, and alligator cracking. The results also indicated that 65% of Jazan's main road network has an average pavement condition rating of very good while only 30% of Jazan's secondary roads network has an average pavement condition.

Mud Brick Resilience

DEFF Research Database (Denmark)

Johannessen, Runa

2012-01-01

In the seemingly endless circle of demolition and illegal rebuilding hand-made mud bricks produced from the soil of contested territory become an act of resistance. In June 2011, the Palestinian village Fasayel encountered the Israeli military’s demolition of 21 of the village’s built structures....

Investigating the Utility of Iron Ore Waste in Preparing Non-fired Bricks

Science.gov (United States)

Lamani, Shreekant R.; Mangalpady, Aruna; Vardhan, Harsha

2017-10-01

Iron ore waste is a major problem for mine owners due to the difficulty involved in its storage, handling and other environmental related issues. An alternative solution to this is utilisation of iron ore waste (IOW) as some value added product in construction industry. An attempt has been made in this paper in examining the possibility of making non-fired bricks from iron ore waste with some additives like cement and fly-ash. Each of the additives were mixed with IOW in different ratios and different sets of bricks were prepared. The prepared IOW bricks were cured for 7, 14, 21 and 28 days and their respective compressive strength and percentage of water absorption were determined. The results show that IOW bricks prepared with 9% and above cement and with 28 days of curing are suitable for brick making and meet the IS specifications. It was also observed that the weight of the prepared bricks with 9% cement with 28 days of curing varies between 2.35 and 2.45 kg whereas the weight of compressed fire clay bricks varies from 2.80 to 2.89 kg. Results also show that the cost of bricks prepared with cement ranging from 9 to 20% is comparable to that of commercially available compressed bricks.

Development of reliable pavement models.

Science.gov (United States)

2011-05-01

The current report proposes a framework for estimating the reliability of a given pavement structure as analyzed by : the Mechanistic-Empirical Pavement Design Guide (MEPDG). The methodology proposes using a previously fit : response surface, in plac...

Verification of mechanistic-empirical design models for flexible pavements through accelerated pavement testing : technical summary.

Science.gov (United States)

2014-08-01

Midwest States Accelerated Pavement Testing Pooled-Fund Program, financed by the : highway departments of Kansas, Iowa, and Missouri, has supported an accelerated : pavement testing (APT) project to validate several models incorporated in the NCHRP :...

Asphalt in Pavement Maintenance.

Science.gov (United States)

Asphalt Inst., College Park, MD.

Maintenance methods that can be used equally well in all regions of the country have been developed for the use of asphalt in pavement maintenance. Specific information covering methods, equipment and terminology that applies to the use of asphalt in the maintenance of all types of pavement structures, including shoulders, is provided. In many…

New Jersey Micro-Surface Pavement Noise Evaluation

OpenAIRE

Hencken, John; Haas, Edwin; Tulanowski, Michael; Bennert, Thomas

2015-01-01

New Jersey DOT is evaluating pavement preservation types for interstate resurfacing as a method to increase network pavement life cycles within depressed budgetary limits. Despite the economic benefits for micro-surface there is concern for the noise quality and pavement noise levels, which will become a significant issue to a greater population as the application increases over an increased area of lane miles throughout the state. Pavement noise research has been conducted on in-service pave...

Reissner-Nordstrom Black Hole Entropy Inside and Outside the Brick Wall

Institute of Scientific and Technical Information of China (English)

刘文彪

2003-01-01

Applying the generalized uncertainty relation to the calculation of the free energy and entropy of a Reissner Nordstrom black hole inside the brick wall, the entropy proportional to the horizon area is derived from the contribution of the vicinity of the horizon. This is compared with the entropy calculated via the original brick wall model. The entropy given by the original brick wall model comes from the outside of the brick wall seemingly.The inside result using generalized uncertainty relation is similar to the outside result using original uncertainty relation, and the divergence inside the brick wall disappears. It is apparent that the cutoff is something related to the quantum theory of gravity.

Identification of indigenous science in the brick-making process through ethnoscience study

Science.gov (United States)

Nuroso, H.; Supriyadi; Sudarmin, S.; Sarwi

2018-03-01

This study aims to find indigenous science in making bricks. In the brick-making process there are concepts of science used for generations obtained through local wisdom. This research method is descriptive qualitative by collecting data through interviews on brick-making home industries in Penggaron village of Semarang city and in Welahan village of Jepara. The result of the research indicates that the indigenous science is in the process of making bricks which includes materials composing, printing, drying, burning and brick quality testing. These findings can be integrated in the course of environmental physics.

Experimental investigation of clay fly ash bricks for gamma-ray shielding

Energy Technology Data Exchange (ETDEWEB)

Mann Harjinder Singh; Mudahar, Gumel Singh [Dept. of Physics, Punjabi University, Patiala (India); Brar, Gurdarshan Singh [Dept. of Higher Education, Additional Project Director, Chandigarh (India); Mann, Kulwinder Singh [Dept. of Applied Sciences, I.K. Gujral Punjab Technical University, Jalandhar (India)

2016-10-15

This study aims to determine the effect of fly ash with a high replacing ratio of clay on the radiation shielding properties of bricks. Some interaction parameters (mass attenuation coefficients, half value layer, effective atomic number, effective electron density, and absorption efficiency) of clay fly ash bricks were measured with a NaI(Tl) detector at 661.6 keV, 1,173.2 keV, and 1,332.5 keV. For the investigation of their shielding behavior, fly ash bricks were molded using an admixture to clay. A narrow beam transmission geometry condition was used for the measurements. The measured values of these parameters were found in good agreement with the theoretical calculations. The elemental compositions of the clay fly ash bricks were analyzed by using an energy dispersive X-ray fluorescence spectrometer. At selected energies the values of the effective atomic numbers and effective electron densities showed a very modest variation with the composition of the fly ash. This seems to be due to the similarity of their elemental compositions. The obtained results were also compared with concrete, in order to study the effect of fly ash content on the radiation shielding properties of clay fly ash bricks. The clay fly ash bricks showed good shielding properties for moderate energy gamma rays. Therefore, these bricks are feasible and eco-friendly compared with traditional clay bricks used for construction.

Utilization of portable effluent wastewater in brick manufacturing

International Nuclear Information System (INIS)

EI-Mahllawy, M.S.; El-Sokkary, T.M.

2005-01-01

Portable wastewater is produced from sedimentation and filtration tanks in portable water treatment plants. Usually, this useless wastewater is drained into River Nile Canal and not to the sewer system causing a potential pollution. Wastewater has been taken from Portable Treatment Plant located at Qalubia Province, Delta, Egypt. Evaluation of raw materials was carried out by using X-ray diffraction (XRD), X-ray fluorescence (XRF), thermal analyses (DTA and TGA) as well as plasticity and drying sensitivity coefficient (DSC) measurements. Technological properties of fired bricks were investigated according to Egyptian and American Specifications. The obtained experimental results encourage substitution of the drained portable wastewater for the tap water in bricks manufacturing. Thus, utilization of the studied portable effluent wastewater in such industry is possible and fulfills the double target of saving drinking water used in clay bricks manufacturing, rather than its environmental pollution prevention. Keywords: Portable wastewater, tap water, clay building bricks, physicomechanical properties

Incorporation feasibility of leather residues in bricks

Energy Technology Data Exchange (ETDEWEB)

Aguiar, J.B. [Minho Univ. (Portugal). Civil Engineering Dept.; Valente, A.; Pires, M.J. [Inst. of Development and Innovation Technology of Minho, Braga (Portugal); Tavares, T. [Biological Engineering Dept., Univ. of Minho, Braga (Portugal)

2002-07-01

The footwear industry has strips of leather as one of its by-products. These leather residues, due to their high chromium content, can be regarded as a threat to the environment, particularly if no care is taken with their disposal. With the incorporation of the residues in ceramic products, after trituration, is possible to neutralise the eventual toxicity of chromium. In a laboratory study we produced prismatic bricks using clay from the region and incorporating 1, 3 and 5% (by mass) of leather residues. This corresponds at about 20, 60 and 100% (by apparent volume). The moulds were filled up with paste and, in order to have some compactness, the ceramic paste was compressed with a spatula. After that, it began the process of drying and burning the bricks. They were tested to flexure, compression and leaching. The results showed that the toxicity of chromium disappeared in the bricks. The mechanical tests showed a decrease in strength for the specimens with leather residue. The compressive strength decreases about 22% for 1% of incorporation of leather residue. However, as bricks were lighter and more porous, we can expect that they are better for thermal isolation. (orig.)

Nondestructive testing of pavements and pavement bases (a bibliography with abstracts). Report for 1964--Dec 1975

International Nuclear Information System (INIS)

Habercom, G.E. Jr.

1976-02-01

Eighty references on nondestructive methods for quality assurance of pavements and pavement bases are presented. Vibration, nuclear activation, radiometry, and acoustic detection are among the various techniques employed

Status report on pavement management.

Science.gov (United States)

1984-01-01

This report traces the developments in pavement management in the Virginia Department of Highways and Transportation from the initial efforts in the mid-1970s through early 1984. Included are status reports on pavement management for the interstate, ...

Proactive pavement asset management with climate change aspects

Science.gov (United States)

Zofka, Adam

2018-05-01

Pavement Asset Management System is a systematic and objective tool to manage pavement network based on the rational, engineering and economic principles. Once implemented and mature Pavement Asset Management System serves the entire range of users starting with the maintenance engineers and ending with the decision-makers. Such a system is necessary to coordinate agency management strategy including proactive maintenance. Basic inputs in the majority of existing Pavement Asset Management System approaches comprise the actual pavement inventory with associated construction history and condition, traffic information as well as various economical parameters. Some Pavement Management System approaches include also weather aspects which is of particular importance considering ongoing climate changes. This paper presents challenges in implementing the Pavement Asset Management System for those National Road Administrations that manage their pavement assets using more traditional strategies, e.g. worse-first approach. Special considerations are given to weather-related inputs and associated analysis to demonstrate the effects of climate change in a short- and long-term range. Based on the presented examples this paper concludes that National Road Administrations should account for the weather-related factors in their Pavement Management Systems as this has a significant impact on the system outcomes from the safety and economical perspective.

Brane brick models in the mirror

Energy Technology Data Exchange (ETDEWEB)

Franco, Sebastián [Physics Department, The City College of the CUNY,160 Convent Avenue, New York, NY 10031 (United States); The Graduate School and University Center, The City University of New York,365 Fifth Avenue, New York NY 10016 (United States); Lee, Sangmin [Center for Theoretical Physics, Seoul National University,Seoul 08826 (Korea, Republic of); Department of Physics and Astronomy, Seoul National University,Seoul 08826 (Korea, Republic of); College of Liberal Studies, Seoul National University,Seoul 08826 (Korea, Republic of); Seong, Rak-Kyeong [School of Physics, Korea Institute for Advanced Study,Seoul 02455 (Korea, Republic of); Vafa, Cumrun [Jefferson Physical Laboratory, Harvard University,Cambridge, MA 02138 (United States)

2017-02-21

Brane brick models are Type IIA brane configurations that encode the 2dN=(0,2) gauge theories on the worldvolume of D1-branes probing toric Calabi-Yau 4-folds. We use mirror symmetry to improve our understanding of this correspondence and to provide a systematic approach for constructing brane brick models starting from geometry. The mirror configuration consists of D5-branes wrapping 4-spheres and the gauge theory is determined by how they intersect. We also explain how 2d(0,2) triality is realized in terms of geometric transitions in the mirror geometry. Mirror symmetry leads to a geometric unification of dualities in different dimensions, where the order of duality is n−1 for a Calabi-Yau n-fold. This makes us conjecture the existence of a quadrality symmetry in 0d. Finally, we comment on how the M-theory lift of brane brick models connects to the classification of 2d(0,2) theories in terms of 4-manifolds.

Effects of waste glass additions on quality of textile sludge-based bricks.

Science.gov (United States)

Rahman, Ari; Urabe, Takeo; Kishimoto, Naoyuki; Mizuhara, Shinji

2015-01-01

This research investigated the utilization of textile sludge as a substitute for clay in brick production. The addition of textile sludge to a brick specimen enhanced its pores, thus reducing the quality of the product. However, the addition of waste glass to brick production materials improved the quality of the brick in terms of both compressive strength and water absorption. Maximum compressive strength was observed with the following composition of waste materials: 30% textile sludge, 60% clay and 10% waste glass. The melting of waste glass clogged up pores on the brick, which improved water absorption performance and compressive strength. Moreover, a leaching test on a sludge-based brick to which 10% waste glass did not detect significant heavy metal compounds in leachates, with the product being in conformance with standard regulations. The recycling of textile sludge for brick production, when combined with waste glass additions, may thus be promising in terms of both product quality and environmental aspects.

Feasibility study on utilization of palm fibre waste into fired clay brick

Science.gov (United States)

Kadir, A. A.; Sarani, N. A.; Zaman, N. N.; Abdullah, Mohd Mustafa Al Bakri

2017-04-01

Malaysia is the second largest of palm oil producer after Indonesia, which contribute to 50 % of palm oil production. With this demand, the increasing of palm oil plantation over the years has led to the large production of agricultural waste, for example palm fibre waste. This study investigates different percentages of palm fibre (0 %, 1 %, 5 % and 10 %) to be incorporated into fired clay brick. Manufactured bricks were fired at 1 °C/min heating rate up to 1050 °C. The effects of manufacture bricks on the physical and mechanical properties of manufactured brick were also determined. All brick samples were tested due to the physical and mechanical properties which include dry density, firing shrinkage, initial rate of suction (IRS), water absorption, porosity and compressive strength. Findings show that increasing palm fibre waste affected the properties of brick, which decreased their density, besides increased firing shrinkage, IRS, water absorption, porosity and compressive strength. However, all the manufactured brick still followed the requirement.

Thermal Transmittance of Porous Hollow Clay Brick by Guarded Hot Box Method

Science.gov (United States)

Kim, Joonsoo

2018-03-01

The thermal property of a porous hollow clay brick was determined by measuring the thermal transmittance of the wall made of porous hollow clay bricks. Prior to the production of porous hollow clay bricks, nonporous and porous tiny clay bricks were prepared to determine the physico-mechanical properties by modifying the amount of wood flour and firing temperature. The bricks were produced by uniaxial pressing and then fired in an electric furnace. Their physico-mechanical properties were measured by water absorption, apparent porosity, bulk density, and compressive strength. The porous tiny clay bricks were produced with three types of wood flour: coarse wood flour (1-0.36 mm), medium-sized wood flour (0.36-0.15 mm), and fine wood flour (cement bricks. The two walls had a thermal transmittance of 1.42 and 2.72 W\\cdot m^{-2}\\cdot K^{-1}, respectively. The difference in thermal transmittance was due to the pores created with fine wood flour (< 0.08 mm) as a pore-forming agent.

Use of Greenlandic resources for the production of bricks

DEFF Research Database (Denmark)

Belmonte, Louise Josefine

of e.g. compression strength, open porosity and water absorption can be produced from the sediments. However, the properties largely depend on the processing of the sediment, e.g. firing procedure and initial treatments. • Addition of waste materials, such as the investigated bottom ash and mine...... of produced bricks. • to investigate the link between raw material characteristics, processing details and resulting technical characteristics of bricks produced from a representative sediment occurrence. Furthermore, in relation to the potential for incorporating waste in the produced bricks, the following...... characteristics. • Bricks are heterogeneous materials, which can accommodate materials of wide ranging compositions without losing their technical properties. For this reason, the ceramic industry has been identified as one of the major recipients for waste in the future. Wastes of different types are becoming...

A link of full-scale accelerated pavement testing to long-term pavement performance study in the Western Cape Province of South Africa

CSIR Research Space (South Africa)

Anochie-Boateng, Joseph K

2016-09-01

Full Text Available of Accelerated Pavement Testing in Pavement Sustainability A Link of Full-Scale Accelerated Pavement Testing to Long-Term Pavement Performance Study in the Western Cape Province of South Africa J. K. Anochie-Boateng W. JvdM Steyn C. Fisher L. Truter...

Durability of compressed soil-cement bricks

Directory of Open Access Journals (Sweden)

Acosta Valle, A.

2001-06-01

Full Text Available This papers shows the evaluation process of the durability of compressed soil-cement bricks. A great number of tests were made to determine the behavior of bricks when they are compression loaded and under the influence of moisture. Two different types of soils were used to produce the bricks, a lime-clay soil and a sand one. The sand soil is very resistant. The other one has a limited use. An experimental design was used to test the bricks. It is a rotational and quadratic method with a hexagonal figure which contains replicas at the central point. This method ensures the reliability of test results. Otherwise, it would reduce the amount of specimens necessary for the tests. The optimun moisture content is obtained by using a press machine. It is more rational than the standard Proctor compactation test, because it applies the same type and amount of energy used to produce the bricks. The obtained results show the behavior differences between the two compressed soil-cement bricks subjected to the compression test, water absorption and wetting and drying tests. The durability tests results are very important in the possible use of the bricks produced.

En el trabajo se evalúa la durabilidad de elementos aglomerados de suelo estabilizado. Se realiza un amplio número de ensayos encaminados a determinar el comportamiento frente a la acción de las cargas y la humedad de dos suelos con características diferentes: uno limo-arcilloso y el otro arenoso. Este último presenta resultados muy favorables en ambas direcciones. El otro, con un posible uso más limitado. Se emplea un método de diseño experimental del tipo rotacional cuadrático en hexágono, con réplicas en el punto central, el que garantiza la confiabilidad de los resultados de los ensayos, a la vez que disminuye la cantidad de especímenes a ensayar. Se determina la humedad óptima a utilizar en las diferentes dosificaciones empleando la máquina compactadora, que resulta m

Water extraction out of mortar during brick laying: A NMR study

NARCIS (Netherlands)

Brocken, H.J.P.; Spiekman, M.E.; Pel, L.; Kopinga, K.; Larbi, J.A.

1998-01-01

The water extraction out of mortar during brick laying was studied using nuclear magnetic resonance. The experiments show that using a fired-clay brick, the water is extracted out of the mortar within 3 minutes, whereas in the case of a sand-lime brick this takes about 10 minutes. Prewetting a

Water extraction out of mortar during brick laying : a NMR study

NARCIS (Netherlands)

Brocken, H.J.P.; Spiekman, M.E.; Kopinga, K.; Larbi, J.A.

1998-01-01

The water extraction out of mortar during brick laying was studied using nuclear magnetic resonance. The experiments show that using a fired-clay brick, the water is extracted out of the mortar within 3 minutes, whereas in the case of a sand-lime brick this takes about 10 minutes. Prewetting a

Moisture transport properties of brick – comparison of exposed, impregnated and rendered brick

DEFF Research Database (Denmark)

Hansen, Tessa Kvist; Bjarløv, Søren Peter; Peuhkuri, Ruut

2016-01-01

In regards to internal insulation of preservation worthy brick façades, external moisture sources, such as wind-driven rain exposure, inevitably has an impact on moisture conditions within the masonry construction. Surface treatments, such as hydrophobation or render, may remedy the impacts...... of external moisture. In the present paper the surface absorption of liquid water on masonry façades of untreated, hydrophobated and rendered brick, are determined experimentally and compared. The experimental work focuses on methods that can be applied on-site, Karsten tube measurements. These measurements...... are supplemented with results from laboratory measurements of water absorption coefficient by partial immersion. Based on obtained measurement results, simulations are made with external liquid water loads for determination of moisture conditions within the masonry of different surface treatments. Experimental...

Pervious Pavement System Evaluation-Paper

Science.gov (United States)

The use of a pervious pavement can be effective as a low impact development stormwater control. The Urban Watershed Management Branch is evaluating interlocking concrete paver systems as a type of porous pavement. Although the pavers are impermeable, the spaces between the pave...

An integrated pavement data management and feedback system (PAMS) : evaluation of pavement condition rating procedure.

Science.gov (United States)

1984-08-01

This report describes an evaluation of a method for use in the Highway Needs Study pavement condition rating. The methods by which the Department generates and manages pavement condition data in the overall process of providing a network of highways ...

Minnesota Local Agency Pavement Marking : Mining Existing Data

Science.gov (United States)

2017-11-01

Pavement marking is important for safety. Maximizing pavement marking performance in terms of increased retroreflectivity, within limited budget constraints, allows agencies to make better decisions toward providing more effective pavement marking pe...

Factors Affecting Pavement Surface and Evaluation Rating Accuracy and Variability

OpenAIRE

Montgomery, Sharlan R; Haddock, John E

2018-01-01

The collection of sufficient, accurate, and consistent pavement condition data is essential to an effective pavement management system. Condition data drive a variety of pavement management tasks such as: • Predicting future pavement performance• Identifying current and future maintenance and rehabilitation needs • Estimating budget needs and requirements • Reporting to decision makers • Selecting appropriate pavement management tools Pavement condition data are represented at either th...

An Exploration of the Nanoworld with LEGO Bricks

Science.gov (United States)

Campbell, Dean J.; Miller, Josiah D.; Bannon, Stephen J.; Obermaier, Lauren M.

2011-01-01

LEGO bricks can be used for a number of demonstrations of chemical structures and properties, especially at the nanoscale level. These bricks can also be used to model instrumentation that probes these structures and properties. Detailed resources about many of these demonstrations are located on the extensive Web site "Exploring the Nanoworld…

0-6673 : improvement in pavement ride, distress, and condition based on different pavement types : [project summary].

Science.gov (United States)

2013-08-01

Each district is required to develop a 4-year : pavement management plan assigning project : treatment categories for the Pavement : Management Information System (PMIS). : However, there are different interpretations in : the districts about what tr...

Corrosion mechanism of carbon brick in the blast furnace hearth by potassium

Science.gov (United States)

Jiao, Ke-xin; Zhang, Jian-liang; Liu, Zheng-jian; Liu, Zhuang-zhuang; Deng, Yong; Fan, Xiaoyue

2017-11-01

Alkali plays a significant role in the formation of brittle layer of carbon brick in the blast furnace hearth. The brittle layer in a commercial blast furnace hearth was investigated. Large amounts of potassium compounds were found in the brittle layer. Subsequently, the carbon bricks which reacted with potassium in the simulation of blast furnace hearth under different contents of potassium in the brick (0.25, 0.5, 1.0 and 2.0 wt.%) during various reaction times (0.5, 1, 2 and 4 h) were experimentally studied. Finally, the formation mechanism of the brittle layer in carbon brick was clarified. The investigation results show that a large number of cracks are present in the brittle layer. The average potassium content in the brittle layer is 1 wt.%. According to the experimental results, cracks in the carbon brick can be formed by the attack of potassium. The reason for the formation of the brittle layer in the carbon brick is that the liquid potassium permeates into the carbon brick through the pores and cracks, and then reacts with SiO2 and Al2O3 in CO atmosphere. The generated potassium compounds nepheline and leucite lead to the volume expansion and the damage of the carbon brick.

Enhancing pavement performance prediction models for the Illinois Tollway System

OpenAIRE

Laxmikanth Premkumar; William R. Vavrik

2016-01-01

Accurate pavement performance prediction represents an important role in prioritizing future maintenance and rehabilitation needs, and predicting future pavement condition in a pavement management system. The Illinois State Toll Highway Authority (Tollway) with over 2000 lane miles of pavement utilizes the condition rating survey (CRS) methodology to rate pavement performance. Pavement performance models developed in the past for the Illinois Department of Transportation (IDOT) are used by th...

75 FR 56556 - Certain Magnesia Carbon Bricks From China and Mexico

Science.gov (United States)

2010-09-16

...)] Certain Magnesia Carbon Bricks From China and Mexico Determinations On the basis of the record \\1... from China and Mexico of certain magnesia carbon bricks, provided for in subheadings 6902.10.10, 6902... the Act (19 U.S.C. 1671b(b)) and that imports of certain magnesia carbon bricks from China and Mexico...

Lightweight Brick by Carbon Ash from The Mixed Plastic Waste Treatment Plant

OpenAIRE

Chen Kuo-Wei

2016-01-01

This study was designed to investigate the mixed plastic waste from the production of light carbon ash bricks performance. The mixed waste plastic pyrolysis process generated waste - Carbon ash. After extrusion, a Lightweight brick was made by carbon ash, additive and Cement mortar. In general, the set compressive strength and insulation effect of lightweight bricks with carbon ash proportion for significant impact. The set water absorption and thermal conductivity of lightweight bricks with ...

Biocalcification using B. pasteurii for strengthening brick masonry civil engineering structures.

Science.gov (United States)

Raut, Supriya H; Sarode, D D; Lele, S S

2014-01-01

Microbiologically induced calcite precipitation in bricks by bacterium Bacillus pasteurii (NCIM 2477) using a media especially optimized for urease production (OptU) was demonstrated in this study. Effect of biocalcification activity on compressive strength and water absorption capacity of bricks was investigated. Various other parameters such as pH, growth profile, urease activity, urea breakdown and calcite precipitated were monitored during the 28 days curing period. Efficiency of B. pasteurii to form microbial aided calcite precipitate in OptU media resulted into 83.9% increase in strength of the bricks as compared to only 24.9% with standard media, nutrient broth (NB). In addition to significant increase in the compressive strength, bricks treated with B. pasteurii grown in OptU media resulted in 48.9 % reduction in water absorption capacity as compared to control bricks immersed in tap water. Thus it was successfully demonstrated that microbial calcification in optimized media by Bacillus pasteurii has good potential for commercial application to improve the life span of structures constructed with bricks, particularly structures of heritage importance.

Geotextiles in Flexible Pavement Construction

Science.gov (United States)

Alungbe, Gabriel D.

2004-01-01

People everywhere in the developed world regularly drive on paved roads. Learning about the construction techniques and materials used in paving benefits technology and construction students. This article discusses the use of geosynthetic textiles in pavement construction. It presents background on pavements and describes geotextiles and drainage…

Feasibility of reclaimed asphalt pavement as aggregate in portland cement concrete pavement, phase II : field demonstration.

Science.gov (United States)

2015-10-01

This research was focused on evaluating the feasibility of using minimally processed reclaimed asphalt pavement (RAP) as : aggregate replacement in concrete pavements. An initial phase of research demonstrated that concretes with up to 50 percent : o...

Brick walls on the brane

International Nuclear Information System (INIS)

Medved, A J M

2002-01-01

The so-called 'brick-wall model' is a semiclassical approach that has been used to explain black hole entropy in terms of thermal matter fields. Here, we apply the brick-wall formalism to thermal bulk fields in a Randall-Sundrum brane world scenario. In this case, the black hole entity is really a string-like object in the anti-de Sitter bulk, while appearing as a Schwarzchild black hole to observers living on the brane. In spite of these exotic circumstances, we establish that the Bekenstein-Hawking entropy law is preserved. Although a similar calculation was recently considered in the literature, this prior study invoked a simplifying assumption (which we avoid) that cannot be adequately justified

Effectiveness of various public private partnership pavement rehabilitation treatments: A big data informatics survival analysis of pavement service life : final report.

Science.gov (United States)

2017-09-29

Past research efforts have used a wide variety of methodological approaches to analyze pavement performance indicators, pavement rehabilitation treatments, and pavement service life. Using big data informatics methods, the intent of this study is to ...

Pavement structure mechanics response of flexible on semi-flexible overlay that based on the old cement concrete pavement damage

Directory of Open Access Journals (Sweden)

Jiang Ruinan

2015-01-01

Full Text Available The old cement pavement damage status directly affect the design of the paving renovation. Based on the state of the old road investigation, combined with the research data at home and abroad, use the control index that average deflection, deflection value and CBR value to determine the reasonable time to overlay. Draw up the typical pavement structure according to the principle of combination of old cement pavement overlay structure design, and calculated that the tensile stress and shear stress in asphalt layer ,semi-flexible layer and the tensile in the old cement pavement adopting BISA3.0 statics finite element analysis model when modulus in the old road was diminishing. Use the computed result to analyses the influence of old road damage condition the influence of pavement structure.

Application of Carbon Composite Bricks for Blast Furnace Hearth

Science.gov (United States)

Zuo, Haibin; Wang, Cong; Zhang, Jianliang; Zhao, Yongan; Jiao, Kexin

Traditional refractory materials for blast furnace hearth lining are mainly composed of carbon bricks and the ceramic cup. However, these materials can't meet the demands for long service life design of blast furnaces. In this paper, a new refractory called carbon composite brick (CCB) was introduced, which combined the advantages of carbon bricks and the ceramic cup. In this case, the resistance of the CCB against corrosion was equal to the ceramic cup and the thermal conductivity of the CCB was equal to carbon bricks. From the results of more than 20 blast furnaces, the CCB could be well used in small blast furnaces and large blast furnaces. In the bad condition of low grade burden and high smelting intensity, the CCB gave full play to the role of cooling system, and effectively resisted the erosion of hot metal to improve the service life of blast furnaces.

Desalination of a brick by application of an electric DC field

DEFF Research Database (Denmark)

Ottosen, Lisbeth M.; Rörig-Dalgaard, Inge

2009-01-01

developing an electrochemical desalination method for brick masonry. Experiments were conducted in laboratory scale with one type of bricks that were contaminated with either NaCl or KCl through submersion in salt solutions prior to application of current. It was seen that NaCl was slower supplied...... to the brick during submersion and slower removed in the applied electric field than KCl. This indicates that the removal rate of chloride depends on the associated cation and this must be taken into account when desiding the duration of full scale actions. The electrochemical desalination was very efficient...... and 99% removal of chloride was obtained. The final concentration in the brick after treatment was less than 10 mg Cl/kg and this concentration is unproblematic. When low salt concentrations were reached during the electrochemical treatment, electroosmotic dewatering of the brick started, showing...

Pavement sound absorption measurements in the U.S.

Science.gov (United States)

2012-08-19

In the U.S., the topic of pavement sound absorption in regard to tire-pavement noise has shown increased interest and research over the last several years. Four types of pavement sound absorption measurements with various applications are discussed: ...

Permanent deformation and deflection relationship from pavement condition assessment

Directory of Open Access Journals (Sweden)

Fabricio Leiva-Villacorta

2017-07-01

Full Text Available The development of permanent deformation in flexible pavements has been a research topic for several decades. Currently there are models included in the structural design of pavements that can predict this type of failure. However, the variables required for the prediction of this distress are complex or difficult to obtain in the field, making its application in pavement evaluation also difficult. Measurement of the deflection of pavement structures by means of non-destructive testing is a technique used to assess the condition of the pavement. This research study seeks to correlate data from deflections of the pavement surface with probable permanent deformation in time. In addition, prediction of the remaining life of the pavement structure using a specified criterion is also analyzed. In order to accomplish these objectives, data acquired from 4 different full scale accelerated pavement test tracks was used to develop a permanent deformation model as a function of deflection, load repetitions and pavement layer thickness. The developed model considered a time series model that incorporates an Auto-regressive parameter of order 1. The proposed model presents an advantage over currently available models because it reduces the required parameters to predict the permanent deformation and/or remaining life in the structure and because these variables can be easily found and updated in a pavement management system. Keywords: HVS, Permanent deformation, Deflections, APT, Time series, Instrumentation

Moisture transfer across the interface between brick and mortar joint

OpenAIRE

Derluyn, Hannelore; Moonen, Peter; Carmeliet, Jan

2008-01-01

This paper reports on experimental and modelling work on moisture transport in masonry, with special attention to the liquid transport across the interface between brick and mortar joint. Experiments and simulations reveal that two aspects need to be taken into account: (1) the dependence of moisture transport properties on the curing of the mortar; (2) the presence of a hydraulic interface resistance between brick and mortar. The resistance is due to imperfect contact between brick and morta...

Development of new baked bricks based on clay and sawdust

Directory of Open Access Journals (Sweden)

Benjeddou Omrane

2018-01-01

Full Text Available Current research in the field of building materials is oriented towards the recovery of waste to ensure the lightening of certain building elements and energy saving. The objective of this study is to produce a new bricks by adding sawdust to clay mixtures. The first part of this experimental work consists on detremining the proper manufacturing process and cooking diagram for these new bricks. In the second part, the effect of the maximum cooking temperature, the firing phase time's of the bricks and the sawdust prportion on the physical and mechanical properties of the new bricks have been studied. The studied properties are the absorption ratio, the unit weight and the compressive strength. The results showed that the addition of an increasing amount of sawdust tends to modify the physical and mechanical properties of the cooked samples. The presence of sawdust reduces the number of connections between the clay grains and produces a lighter, more absorbent and less resistant material. Finally, the results showed that the manufacture of bricks based on sawdust is possible.

Improving rutting resistance of pavement structures using geosynthetics: an overview.

Science.gov (United States)

Mirzapour Mounes, Sina; Karim, Mohamed Rehan; Khodaii, Ali; Almasi, Mohammad Hadi

2014-01-01

A pavement structure consists of several layers for the primary purpose of transmitting and distributing traffic loads to the subgrade. Rutting is one form of pavement distresses that may influence the performance of road pavements. Geosynthetics is one type of synthetic materials utilized for improving the performance of pavements against rutting. Various studies have been conducted on using different geosynthetic materials in pavement structures by different researchers. One of the practices is a reinforcing material in asphalt pavements. This paper intends to present and discuss the discoveries from some of the studies on utilizing geosynthetics in flexible pavements as reinforcement against permanent deformation (rutting).

Improving Rutting Resistance of Pavement Structures Using Geosynthetics: An Overview

Directory of Open Access Journals (Sweden)

Sina Mirzapour Mounes

2014-01-01

Full Text Available A pavement structure consists of several layers for the primary purpose of transmitting and distributing traffic loads to the subgrade. Rutting is one form of pavement distresses that may influence the performance of road pavements. Geosynthetics is one type of synthetic materials utilized for improving the performance of pavements against rutting. Various studies have been conducted on using different geosynthetic materials in pavement structures by different researchers. One of the practices is a reinforcing material in asphalt pavements. This paper intends to present and discuss the discoveries from some of the studies on utilizing geosynthetics in flexible pavements as reinforcement against permanent deformation (rutting.

Influence of pH during chemical weathering of bricks: Long term exposure

DEFF Research Database (Denmark)

Rörig-Dalgaard, Inge; Charola, A. Elena

2016-01-01

Within the framework of environmental weathering of bricks in historical structures, this study focuses on new bricks currently employed for restoration projects. The bricks were subjected to an accelerated chemical weathering test by immersion in solutions with pH ranging from 3 to 13 for differ...

Life cycle assessment of regional brick manufacture

Directory of Open Access Journals (Sweden)

López-Aguilar, H. A.

2016-06-01

Full Text Available This document presents a Life Cycle Assessment (LCA study to quantify the environmental cradle-to-gate impact of the manufacture of brick for the construction industry, produced with material of igneous source. Its mineral composition and thermal isolation properties were characterized for use in real estate construction. The LCA results for brick manufacture using this material identified the greatest environmental impact to be associated with material extraction and its proportional cement content. Additionally, this document presents an evaluation of the environmental impact of the manufacturing process by comparing traditional fired clay brick and brick of the material under study. In conclusion, the studied material shows thermal insulation qualities and suitability for the manufacture of bricks with low incorporated energy.Este trabajo presenta un estudio de Análisis de Ciclo de Vida (ACV para cuantificar los impactos ambientales de la cuna a la puerta de la manufactura de ladrillos para la industria de la construcción, fabricados de un material de origen ígneo. Se caracterizó su composición mineralógica y propiedades de aislamiento térmico para ser usado en la construcción de inmuebles. Los resultados ACV de la fabricación de ladrillos de este material, identificaron la mayor contribución a los impactos ambientales asociados a la extracción del material y la cantidad proporcional de cemento. Adicionalmente, se presenta una evaluación comparativa del impacto ambiental entre la manufactura de un ladrillo tradicional de arcilla cocido y de un ladrillo del material en estudio. En conclusión el material estudiado muestra cualidades de aislamiento térmico y es adecuado para la fabricación de ladrillos con baja energía incorporada.

Appraisal of the Causes of Pavement

African Journals Online (AJOL)

pavement failure) or structural (deep-seated pavement failure). ... is primarily due to shallow groundwater level. Adewole et al. ... processing and interpretation of Landsat-7 ETM+ images covering the study area and it's environ for lineaments.

Monitoring Thermal Performance of Hollow Bricks with Different Cavity Fillers in Difference Climate Conditions

Science.gov (United States)

Pavlík, Zbyšek; Jerman, Miloš; Fořt, Jan; Černý, Robert

2015-03-01

Hollow brick blocks have found widespread use in the building industry during the last decades. The increasing requirements to the thermal insulation properties of building envelopes given by the national standards in Europe led the brick producers to reduce the production of common solid bricks. Brick blocks with more or less complex systems of internal cavities replaced the traditional bricks and became dominant on the building ceramics market. However, contrary to the solid bricks where the thermal conductivity can easily be measured by standard methods, the complex geometry of hollow brick blocks makes the application of common techniques impossible. In this paper, a steady-state technique utilizing a system of two climatic chambers separated by a connecting tunnel for sample positioning is used for the determination of the thermal conductivity, thermal resistance, and thermal transmittance ( U value) of hollow bricks with the cavities filled by air, two different types of mineral wool, polystyrene balls, and foam polyurethane. The particular brick block is provided with the necessary temperature- and heat-flux sensors and thermally insulated in the tunnel. In the climatic chambers, different temperatures are set. After steady-state conditions are established in the measuring system, the effective thermal properties of the brick block are calculated using the measured data. Experimental results show that the best results are achieved with hydrophilic mineral wool as a cavity filler; the worst performance exhibits the brick block with air-filled cavities.

Drainage investigation of surface runoff for highway pavement

Directory of Open Access Journals (Sweden)

Al-adili Aqeel

2018-01-01

Full Text Available The aim of this study is to establish the effect of heavy rainfall and the chosen pavement layers on the drainage design, material selection and rutting resistance of the flexible pavement. The test in present study was started with wheel track passing without load and without rain falling on the pavement for a period of time, and it was noticed that no distress appeared on the surface of the pavement. Then, the load is gradually added by using wheel track load of 106 psi for five tests without rain falling and five other tests with gradually increasing rain fall duration and intensity. Deterioration and distresses appeared on the pavement when increasing the wheel track load to (150 psi under high intensity rain and long term duration of rain fall. By increasing the number of days, which is 103 days of study, when the pavement is saturated, the extra amount of the water will runoff. The clogging material which caused a decrease in the water seepage, increases the time of runoff ending. The clogging materials of fine particles that get deposited on the surface of the pavement resulted by passing the wheel track loading and wear & tear of the pavement surface, and other clogging materials such as salt in the water will penetrate to the pavement and seal the voids and decrease its water seepage. The water seepage decreases by increasing number of days, so the amount of the absorbed water decreases by 89% after 71 days of testing for high rain intensity (116 ml/min..

Optimizing the Physical, Mechanical and Hygrothermal Performance of Compressed Earth Bricks

Directory of Open Access Journals (Sweden)

Esther Obonyo

2011-03-01

Full Text Available The paper is based on findings from research that assesses the potential for enhancing the performance of compressed earth bricks. A set of experiments was carried out to assess the potential for enhancing the bricks’ physical, mechanical and hygrothermal performance through the design of an optimal stabilization strategy. Three different types of bricks were fabricated: soil-cement, soil-cement-lime, and soil-cement-fiber. The different types of bricks did not exhibit significant differences in performances when assessed on the basis of porosity, density, water absorption, and compressive strength. However, upon exposure to elevated moisture and temperature conditions, the soil-cement-fiber bricks had the highest residual strength (87%. The soil-cement and soil-cement-lime bricks had residual strength values of 48.19 and 46.20% respectively. These results suggest that, like any other cement-based material, compressed earth brick properties are affected by hydration-triggered chemical and structural changes occurring in the matrix that would be difficult to isolate using tests that focus on “bulk” changes. The discussion in this paper presents findings from a research effort directed at quantifying the specific changes through an analysis of the microstructure.

Utilization of crushed clay brick in cellular concrete production

Directory of Open Access Journals (Sweden)

Ali A. Aliabdo

2014-03-01

Full Text Available The main objective of this research program is to study the effect of using crushed clay brick as an alternative aggregate in aerated concrete. Two series of mixtures were designed to investigate the physico-mechanical properties and micro-structural analysis of autoclave aerated concrete and foamed concrete, respectively. In each series, natural sand was replaced with crushed clay brick aggregate. In both series results showed a significant reduction in unit weight, thermal conductivity and sound attenuation coefficient while porosity has increased. Improvement on compressive strength of autoclave aerated concrete was observed at a percentage of 25% and 50% replacement, while in foamed concrete compressive strength gradually decreased by increasing crushed clay brick aggregate content. A comparatively uniform distribution of pore in case of foamed concrete with natural sand was observed by scanning electron microscope, while the pores were connected mostly and irregularly for mixes containing a percentage higher than 25% clay brick aggregate.

GPU-based simulations of fracture in idealized brick and mortar composites

Science.gov (United States)

William Pro, J.; Kwei Lim, Rone; Petzold, Linda R.; Utz, Marcel; Begley, Matthew R.

2015-07-01

Stiff ceramic platelets (or bricks) that are aligned and bonded to a second ductile phase with low volume fraction (mortar) are a promising pathway to produce stiff, high-toughness composites. For certain ranges of constituent properties, including those of some synthetic analogs to nacre, one can demonstrate that the deformation is dominated by relative brick motions. This paper describes simulations of fracture that explicitly track the motions of individual rigid bricks in an idealized microstructure; cohesive tractions acting between the bricks introduce elastic, plastic and rupture behaviors. Results are presented for the stresses and damage near macroscopic cracks with different brick orientations relative to the loading orientation. The anisotropic macroscopic initiation toughness is computed for small-scale yielding conditions and is shown to be independent of specimen geometry and loading configuration. The results are shown to be in agreement with previously published experiments on synthetic nacre.

Preparation and Mechanical Properties of Pressed Straw Concrete Brick

Science.gov (United States)

Sumarni, S.; Wijanarko, W.

2018-03-01

Rice straws have been widely used as wall filler material in China, Australia, and United States, by spinning them into hays with an approximate dimension of 40 cm of height, 40cm of thickness and 60 cm of width, using a machine. Then, the hays are placed into a wall frame until they fill it completely. After that, the wall frame is covered with wire mesh and plastered. In this research, rice straws are to be used as concrete brick fillers, by pressing the straws into hays and then putting them into the concrete brick mold along with mortar. The objective of this research is to investigate the mechanical properties of concrete brick, namely: compressive strength, specific gravity, and water absorption power. This research used experimental research method. It was conducted by using concrete bricks which had 400 cm of width, 200 cm of height, and 100 cm of thickness, made from rice straws, cement, sand, and water as the test sample. The straws were each made different by their volume. The mortars used in this research were made from cement, sand, and water, with the ratio of 1:7:0.5. The concrete bricks were made by pressing straws mixed with glue into hays, and then cut by determined variations of volume. The variations of hays volume were 0 m3, 0.000625 m3, 0.00075 m3, 0.000875 m3, 0.00125 m3, 0.0015 m3, 0.00175 m3, 0.001875 m3, 0.00225 m3, and 0.002625 m3. There were 3 samples for each volumes of hays. The result shows that the straw concrete bricks reached the maximum compressive strength of 1.92 MPa, specific gravity of 1,702 kg/m3, and water absorption level of 3.9 %. Based on the provided measurements of products in the Standar Nasional Indonesia (Indonesian product standardization), the concrete bricks produced attained the prescribed standard quality.

Inverted base pavements: construction and performance

KAUST Repository

Papadopoulos, Efthymios; Santamarina, Carlos

2017-01-01

quality control. This study reviews the extensive South African experience and case histories in the USA. Accumulating evidence suggests that inverted base pavements are a viable alternative and can outperform conventional pavements at a lower cost

Fatigue and rutting lives in flexible pavement

Directory of Open Access Journals (Sweden)

Ahmed Ebrahim Abu El-Maaty Behiry

2012-12-01

Full Text Available Flexible pavement is designed based on axle load limits and climatic conditions. The Egyptian code has specified certain load limits that should not be exceeded. The overweight trucks cause severe deterioration to the pavement and thus reduce its life. The study aims at studying the effect of axle load increase, and the variation in pavement modulus, on the overall pavement life. The research uses the BISAR software and the Egyptian environmental and pavement materials conditions to estimate the tensile strains occurring under the asphalt concrete (AC layer and the compressive strains above the subgrade surface. The results revealed that tensile and compressive strain increased with increasing axle loads and decreased with increasing asphalt layer modulus thus the violating trucks should be unloaded when their weights exceed certain limits. Base thickness and subgrade resilient modulus were the key elements which control the equilibrium between fatigue and rutting lives.

Using rice straw to manufacture ceramic bricks

Directory of Open Access Journals (Sweden)

Gorbunov German Ivanovich

2014-12-01

Full Text Available In the article, the co-authors offer their advanced and efficient methodologies for the recycling of the rice straw, as well as the novel approaches to the ceramic brick quality improvement through the application of the rice straw as the combustible additive and through the formation of amorphous silica in the course of the rice straw combustion. The co-authors provide characteristics of the raw materials, production techniques used to manufacture ceramic bricks, and their basic properties in the article. The co-authors describe the simulated process of formation of amorphous silica. The process in question has two independent steps (or options: 1 rice straw combustion and ash formation outside the oven (in the oxidizing medium, and further application of ash as the additive in the process of burning clay mixtures; 2 adding pre-treated rice straw as the combustible additive into the clay mixture, and its further burning in compliance with the pre-set temperature mode. The findings have proven that the most rational pre-requisite of the rice straw application in the manufacturing of ceramic bricks consists in feeding milled straw into the clay mixture to be followed by molding, drying and burning. Brick samples are highly porous, and they also demonstrate sufficient compressive strength. The co-authors have also identified optimal values of rice straw and ash content in the mixtures under research.

Lightweight Brick by Carbon Ash from The Mixed Plastic Waste Treatment Plant

Directory of Open Access Journals (Sweden)

Chen Kuo-Wei

2016-01-01

Full Text Available This study was designed to investigate the mixed plastic waste from the production of light carbon ash bricks performance. The mixed waste plastic pyrolysis process generated waste - Carbon ash. After extrusion, a Lightweight brick was made by carbon ash, additive and Cement mortar. In general, the set compressive strength and insulation effect of lightweight bricks with carbon ash proportion for significant impact. The set water absorption and thermal conductivity of lightweight bricks with carbon ash proportion for significant impact. The set density of lightweight brick ameliorates with M3824 additive and CM3 cement mortar for significant impact. Under conditions of technology and economic, the results of this study as reference for market-oriented marketing and commercialization of production.

Characterization of grog of bricks

International Nuclear Information System (INIS)

Candido, V.S.; Pinheiro, R.M.; Monteiro, S.N.; Vieira, C.M.F.

2010-01-01

This work aims to characterize a waste of red ceramic, grog, generated from the milling of defective pieces of bricks fired in a Hoffmann type furnace by a industry from Campos dos Goytacazes-RJ. The grog was tested for X-ray diffraction, X-ray fluorescence, thermogravimetric and differential thermal analysis, dilatometry, sieving and sedimentation by gravity and optical microscopy. The results indicated that the grog is predominantly constituted of quartz, muscovite mica and hematite. The presence of kaolinite indicates that the bricks were fired at low temperatures, below 600 deg C. Finally, the characterization results indicated that the grog presents itself as an alternative non plastic material to be used in mixtures with clays for the production of red ceramics. (author)

Pavement Pre- and Post-Treatment Performance Models Using LTPP Data

OpenAIRE

Lu, Pan; Tolliver, Denver

2012-01-01

This paper determines that pavement performance in International Roughness Index (IRI) is affected by exogenous interventions such as pavement age, precipitation level, freeze-thaw level, and lower level preservation maintenance strategies. An exponential function of pavement age was used to represent pavement IRI performance curves. Moreover, this paper demonstrates a method which calculates short-term post-pavement performance models from maintenance effect models and pre-treatment performa...

Knowledge Discovery and Pavement Performance : Intelligent Data Mining

NARCIS (Netherlands)

Miradi, M.

2009-01-01

The main goal of the study was to discover knowledge from data about asphalt road pavement problems to achieve a better understanding of the behavior of them and via this understanding improve pavement quality and enhance its lifespan. Four pavement problems were chosen to be investigated; raveling

Durability of Compressed Earth Bricks: Assessing Erosion Resistance Using the Modified Spray Testing

Directory of Open Access Journals (Sweden)

Malarvizhi Baskaran

2010-11-01

Full Text Available The discussion in this paper is part of research directed at establishing optimal stabilization strategy for compressed bricks. The deployment context for the use of the compressed bricks was Dar es Salaam (Tanzania where manually fabricated bricks are increasingly being used in low cost housing units. This discussion specifically focuses on strategies that can be used to counter deterioration due to wind-driven rain erosion. The impact of using cement, lime, fiber and a commercial stabilizing fluid was assessed. Factory-produced bricks were used for benchmarking. The durability of the bricks was assessed using the “modified” Bulletin 5 Spray Test. The different brick specimens were sprayed with water at 2.07 MPa and 4.14 MPa over one-hour time period while measuring the depth of erosion every 15 minutes. Factory-produced bricks hardly eroded at both 2.07 MPa and 4.14 MPa pressure levels. The maximum depth of erosion for Soil-Cement bricks ranged from a maximum of 0.5 mm at 2.07 MPa water pressure to 0.8 mm at 4.14 MPa. The maximum and minimum depths of erosion for Soil-Cement-Lime bricks were 25mm and 17 mm respectively. The inclusion of natural fiber in the bricks resulted in a sharp increase of the erosion depth to a maximum of 40 mm at 2.07 MPa and 55 mm at 4.14 Mpa. As the use of natural fibers and lime enhances some physio-mechanical properties, further research is necessary to determine ways of achieving this goal while maintaining acceptable levels of erosion resistance.

Evaluation of current Louisiana flexible pavement structures using PMS data and new M-E pavement design guide.

Science.gov (United States)

2010-10-01

The proposed study uses the new MEPDG together with data available from LADOTDs Pavement Management System (PMS) and other data sources from LADOTDs main frame to evaluate typical flexible pavement structures currently used and to make changes ...

Equivalent damage of loads on pavements

CSIR Research Space (South Africa)

Prozzi, JA

2009-05-26

Full Text Available This report describes a new methodology for the determination of Equivalent Damage Factors (EDFs) of vehicles with multiple axle and wheel configurations on pavements. The basic premise of this new procedure is that "equivalent pavement response...

Finite element stress analysis of brick-mortar masonry under ...

African Journals Online (AJOL)

Stress analysis of a brick-mortar couplet as a substitute for brick wall structure has been performed by finite element method, and algorithm for determining the element stiffness matrix for a plane stress problem using the displacement approach was developed. The nodal displacements were derived for the stress in each ...

Surface Distresses Detection of Pavement Based on Digital Image Processing

OpenAIRE

Ouyang , Aiguo; Luo , Chagen; Zhou , Chao

2010-01-01

International audience; Pavement crack is the main form of early diseases of pavement. The use of digital photography to record pavement images and subsequent crack detection and classification has undergone continuous improvements over the past decade. Digital image processing has been applied to detect the pavement crack for its advantages of large amount of information and automatic detection. The applications of digital image processing in pavement crack detection, distresses classificati...

Smart bricks for strain sensing and crack detection in masonry structures

Science.gov (United States)

Downey, Austin; D'Alessandro, Antonella; Laflamme, Simon; Ubertini, Filippo

2018-01-01

The paper proposes the novel concept of smart bricks as a durable sensing solution for structural health monitoring of masonry structures. The term smart bricks denotes piezoresistive clay bricks with suitable electronics capable of outputting measurable changes in their electrical properties under changes in their state of strain. This feature can be exploited to evaluate stress at critical locations inside a masonry wall and to detect changes in loading paths associated with structural damage, for instance following an earthquake. Results from an experimental campaign show that normal clay bricks, fabricated in the laboratory with embedded electrodes made of a special steel for resisting the high baking temperature, exhibit a quite linear and repeatable piezoresistive behavior. That is a change in electrical resistance proportional to a change in axial strain. In order to be able to exploit this feature for strain sensing, high-resolution electronics are used with a biphasic DC measurement approach to eliminate any resistance drift due to material polarization. Then, an enhanced nanocomposite smart brick is proposed, where titania is mixed with clay before baking, in order to enhance the brick’s mechanical properties, improve its noise rejection, and increase its electrical conductivity. Titania was selected among other possible conductive nanofillers due to its resistance to high temperatures and its ability to improve the durability of construction materials while maintaining the aesthetic appearance of clay bricks. An application of smart bricks for crack detection in masonry walls is demonstrated by laboratory testing of a small-scale wall specimen under different loading conditions and controlled damage. Overall, it is demonstrated that a few strategically placed smart bricks enable monitoring of the state of strain within the wall and provide information that is capable of crack detection.

Hybrid green permeable pave with hexagonal modular pavement systems

International Nuclear Information System (INIS)

Rashid, M A; Abustan, I; Hamzah, M O

2013-01-01

Modular permeable pavements are alternatives to the traditional impervious asphalt and concrete pavements. Pervious pore spaces in the surface allow for water to infiltrate into the pavement during rainfall events. As of their ability to allow water to quickly infiltrate through the surface, modular permeable pavements allow for reductions in runoff quantity and peak runoff rates. Even in areas where the underlying soil is not ideal for modular permeable pavements, the installation of under drains has still been shown to reflect these reductions. Modular permeable pavements have been regarded as an effective tool in helping with stormwater control. It also affects the water quality of stormwater runoff. Places using modular permeable pavement has been shown to cause a significant decrease in several heavy metal concentrations as well as suspended solids. Removal rates are dependent upon the material used for the pavers and sub-base material, as well as the surface void space. Most heavy metals are captured in the top layers of the void space fill media. Permeable pavements are now considered an effective BMP for reducing stormwater runoff volume and peak flow. This study examines the extent to which such combined pavement systems are capable of handling load from the vehicles. Experimental investigation were undertaken to quantify the compressive characteristics of the modular. Results shows impressive results of achieving high safety factor for daily life vehicles.

Nondestructive testing of pavements and pavement bases. (a bibliography with abstracts). Report for 1964-Jan 78

International Nuclear Information System (INIS)

Habercom, G.E. Jr.

1978-01-01

Nondestructive methods for quality assurance of pavements and pavement bases are investigated in these Government-sponsored research reports. Vibration, nuclear activation, radiometry, and acoustic detection are among the various techniques employed. The updated bibliography contains 114 abstracts, 17 of which are new entries to the previous edition

Implementing energy efficient pavements: A socio-economic analysis of the development and implementation of energy efficient pavements with low rolling resistance

DEFF Research Database (Denmark)

Axelsen, Christian; Pettinari, Matteo; Schmidt, Bjarne

2017-01-01

for the transportation sector is to make road networks more energy efficient by implementing pavements with low rolling resistance, leading to lower fuel consumption. Through a series of projects focusing on reducing rolling resistance conducted since 2010, the Danish Road Directorate (DRD) has developed a durable......, energy-efficient asphalt pavement. Socio-economic analyses conducted to quantify the benefit to society associated with implementing these asphalt pavements have demonstrated very high benefits. The demonstrated results in terms of durability, energy efficiency and socio-economics have resulted...... in substantial government funding being provided for demonstration trials on 50 kilometers of energy-efficient pavement in 2018. The implementation of energy-efficient pavements will enable Denmark to contribute to the out-of-quota 2030-emission cuts in line with EU regulations....

Molecular mechanisms controlling pavement cell shape in Arabidopsis leaves.

Science.gov (United States)

Qian, Pingping; Hou, Suiwen; Guo, Guangqin

2009-08-01

Pavement cells have an interlocking jigsaw puzzle-shaped leaf surface pattern. Twenty-three genes involved in the pavement cell morphogenesis were discovered until now. The mutations of these genes through various means lead to pavement cell shape defects, such as loss or lack of interdigitation, the reduction of lobing, gaps between lobe and neck regions in pavement cells, and distorted trichomes. These phenotypes are affected by the organization of microtubules and microfilaments. Microtubule bands are considered corresponding with the neck regions of the cell, while lobe formation depends on patches of microfilaments. The pathway of Rho of plant (ROP) GTPase signaling cascades regulates overall activity of the cytoskeleton in pavement cells. Some other proteins, in addition to the ROPs, SCAR/WAVE, and ARP2/3 complexes, are also involved in the pavement cell morphogenesis.

Air pollution hazards in brick kilns

Energy Technology Data Exchange (ETDEWEB)

Aslam, M; Srivastava, R S; Minocha, A K; Gupta, R G [Central Building Research Institute, Roorkee (India)

1994-02-01

Three types of brick kiln - Bull's trench kiln of movable chimney type, Bull's trench kiln of fixed chimney type, and high draught kiln of normal capacity (25,000-30,000 bricks/day) fed manually with slack coal and other local fuels - were investigated for stack emissions. Dust and hydrocarbons were identified as chief pollutants. Particle size analysis of dust emitted from movable chimney kiln and its impact on ambient air quality were also studied. Based on these studies, recommendations have been drawn on their comparative pollution hazard and need for optimization of operational parameters to improve their thermal performance and reduce pollution emission. 15 refs., 4 tabs.

Calibrating mechanistic-empirical pavement performance models with an expert matrix

Energy Technology Data Exchange (ETDEWEB)

Tighe, S.; AlAssar, R.; Haas, R. [Waterloo Univ., ON (Canada). Dept. of Civil Engineering; Zhiwei, H. [Stantec Consulting Ltd., Cambridge, ON (Canada)

2001-07-01

Proper management of pavement infrastructure requires pavement performance modelling. For the past 20 years, the Ontario Ministry of Transportation has used the Ontario Pavement Analysis of Costs (OPAC) system for pavement design. Pavement needs, however, have changed substantially during that time. To address this need, a new research contract is underway to enhance the model and verify the predictions, particularly at extreme points such as low and high traffic volume pavement design. This initiative included a complete evaluation of the existing OPAC pavement design method, the construction of a new set of pavement performance prediction models, and the development of the flexible pavement design procedure that incorporates reliability analysis. The design was also expanded to include rigid pavement designs and modification of the existing life cycle cost analysis procedure which includes both the agency cost and road user cost. Performance prediction and life-cycle costs were developed based on several factors, including material properties, traffic loads and climate. Construction and maintenance schedules were also considered. The methodology for the calibration and validation of a mechanistic-empirical flexible pavement performance model was described. Mechanistic-empirical design methods combine theory based design such as calculated stresses, strains or deflections with empirical methods, where a measured response is associated with thickness and pavement performance. Elastic layer analysis was used to determine pavement response to determine the most effective design using cumulative Equivalent Single Axle Loads (ESALs), below grade type and layer thickness.The new mechanistic-empirical model separates the environment and traffic effects on performance. This makes it possible to quantify regional differences between Southern and Northern Ontario. In addition, roughness can be calculated in terms of the International Roughness Index or Riding comfort Index

ZettaBricks: A Language Compiler and Runtime System for Anyscale Computing

Energy Technology Data Exchange (ETDEWEB)

Amarasinghe, Saman [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

2015-03-27

This grant supported the ZettaBricks and OpenTuner projects. ZettaBricks is a new implicitly parallel language and compiler where defining multiple implementations of multiple algorithms to solve a problem is the natural way of programming. ZettaBricks makes algorithmic choice a first class construct of the language. Choices are provided in a way that also allows our compiler to tune at a finer granularity. The ZettaBricks compiler autotunes programs by making both fine-grained as well as algorithmic choices. Choices also include different automatic parallelization techniques, data distributions, algorithmic parameters, transformations, and blocking. Additionally, ZettaBricks introduces novel techniques to autotune algorithms for different convergence criteria. When choosing between various direct and iterative methods, the ZettaBricks compiler is able to tune a program in such a way that delivers near-optimal efficiency for any desired level of accuracy. The compiler has the flexibility of utilizing different convergence criteria for the various components within a single algorithm, providing the user with accuracy choice alongside algorithmic choice. OpenTuner is a generalization of the experience gained in building an autotuner for ZettaBricks. OpenTuner is a new open source framework for building domain-specific multi-objective program autotuners. OpenTuner supports fully-customizable configuration representations, an extensible technique representation to allow for domain-specific techniques, and an easy to use interface for communicating with the program to be autotuned. A key capability inside OpenTuner is the use of ensembles of disparate search techniques simultaneously; techniques that perform well will dynamically be allocated a larger proportion of tests.

Molecular mechanics of DNA bricks: in situ structure, mechanical properties and ionic conductivity

International Nuclear Information System (INIS)

Slone, Scott Michael; Li, Chen-Yu; Aksimentiev, Aleksei; Yoo, Jejoong

2016-01-01

The DNA bricks method exploits self-assembly of short DNA fragments to produce custom three-dimensional objects with subnanometer precision. In contrast to DNA origami, the DNA brick method permits a variety of different structures to be realized using the same library of DNA strands. As a consequence of their design, however, assembled DNA brick structures have fewer interhelical connections in comparison to equivalent DNA origami structures. Although the overall shape of the DNA brick objects has been characterized and found to conform to the features of the target designs, the microscopic properties of DNA brick objects remain yet to be determined. Here, we use the all-atom molecular dynamics method to directly compare the structure, mechanical properties and ionic conductivity of DNA brick and DNA origami structures different only by internal connectivity of their consistituent DNA strands. In comparison to equivalent DNA origami structures, the DNA brick structures are found to be less rigid and less dense and have a larger cross-section area normal to the DNA helix direction. At the microscopic level, the junction in the DNA brick structures are found to be right-handed, similar to the structure of individual Holliday junctions (HJ) in solution, which contrasts with the left-handed structure of HJ in DNA origami. Subject to external electric field, a DNA brick plate is more leaky to ions than an equivalent DNA origami plate because of its lower density and larger cross-section area. Overall, our results indicate that the structures produced by the DNA brick method are fairly similar in their overall appearance to those created by the DNA origami method but are more compliant when subject to external forces, which likely is a consequence of their single crossover design. (paper)

Crack identification for rigid pavements using unmanned aerial vehicles

Science.gov (United States)

Bahaddin Ersoz, Ahmet; Pekcan, Onur; Teke, Turker

2017-09-01

Pavement condition assessment is an essential piece of modern pavement management systems as rehabilitation strategies are planned based upon its outcomes. For proper evaluation of existing pavements, they must be continuously and effectively monitored using practical means. Conventionally, truck-based pavement monitoring systems have been in-use in assessing the remaining life of in-service pavements. Although such systems produce accurate results, their use can be expensive and data processing can be time consuming, which make them infeasible considering the demand for quick pavement evaluation. To overcome such problems, Unmanned Aerial Vehicles (UAVs) can be used as an alternative as they are relatively cheaper and easier-to-use. In this study, we propose a UAV based pavement crack identification system for monitoring rigid pavements’ existing conditions. The system consists of recently introduced image processing algorithms used together with conventional machine learning techniques, both of which are used to perform detection of cracks on rigid pavements’ surface and their classification. Through image processing, the distinct features of labelled crack bodies are first obtained from the UAV based images and then used for training of a Support Vector Machine (SVM) model. The performance of the developed SVM model was assessed with a field study performed along a rigid pavement exposed to low traffic and serious temperature changes. Available cracks were classified using the UAV based system and obtained results indicate it ensures a good alternative solution for pavement monitoring applications.

Serviceable pavement marking retroreflectivity levels : technical report.

Science.gov (United States)

2009-03-01

This research addressed an array of issues related to measuring pavement markings retroreflectivity, factors : related to pavement marking performance, subjective evaluation process, best practices for using mobile : retroreflectometers, sampling pav...

Evaluation of Procedures for Backcalculation of Airfield Pavement Moduli

Science.gov (United States)

2015-08-01

ER D C/ G SL T R -1 5 -3 1 Evaluation of Procedures for Backcalculation of Airfield Pavement Moduli G eo te ch n ic al a n d S tr u...August 2015 Evaluation of Procedures for Backcalculation of Airfield Pavement Moduli Lucy P. Priddy and Carlos R. Gonzalez Geotechnical and...USAF’s) airfield pavement structural evaluation procedures. Determining the structural integrity of airfield pavement relies on the analysis of

23 CFR 973.208 - Indian lands pavement management system (PMS).

Science.gov (United States)

2010-04-01

... 23 Highways 1 2010-04-01 2010-04-01 false Indian lands pavement management system (PMS). 973.208... PROGRAM Bureau of Indian Affairs Management Systems § 973.208 Indian lands pavement management system (PMS... concepts described in the AASHTO's “Pavement Management Guide.” 1 1 “Pavement Management Guide,” AASHTO...

Cost-Effective Pavement Performance Management of Indiana's Enhanced National Highway System through Strategic Modification of the Pavement Rehabilitation Treatment Trigger Values

OpenAIRE

Noureldin, Menna; Fricker, Jon D.; Sinha, Kumares C.

2015-01-01

Cost-Effective Pavement Performance Management of Indiana's Enhanced National Highway System through Strategic Modification of the Pavement Rehabilitation Treatment Trigger Values Presented during Session 3: Policy and Funding, moderated by Magdy Mikhail, at the 9th International Conference on Managing Pavement Assets (ICMPA9) in Alexandria, VA. Includes conference paper and PowerPoint slides.

Quantitative analysis of microtubule orientation in interdigitated leaf pavement cells.

Science.gov (United States)

Akita, Kae; Higaki, Takumi; Kutsuna, Natsumaro; Hasezawa, Seiichiro

2015-01-01

Leaf pavement cells are shaped like a jigsaw puzzle in most dicotyledon species. Molecular genetic studies have identified several genes required for pavement cells morphogenesis and proposed that microtubules play crucial roles in the interdigitation of pavement cells. In this study, we performed quantitative analysis of cortical microtubule orientation in leaf pavement cells in Arabidopsis thaliana. We captured confocal images of cortical microtubules in cotyledon leaf epidermis expressing GFP-tubulinβ and quantitatively evaluated the microtubule orientations relative to the pavement cell growth axis using original image processing techniques. Our results showed that microtubules kept parallel orientations to the growth axis during pavement cell growth. In addition, we showed that immersion treatment of seed cotyledons in solutions containing tubulin polymerization and depolymerization inhibitors decreased pavement cell complexity. Treatment with oryzalin and colchicine inhibited the symmetric division of guard mother cells.

Numerical Simulation of Tire-Pavement Interaction

NARCIS (Netherlands)

Srirangam, S.K.

2015-01-01

Good skid resistance of a pavement surface is essential for road safety. Loss of skid resistance can lead to property damage and loss of lives. Ever increasing need of driver safety poses challenges to the highway authorities to evaluate pavement conditions even more precisely under different

Urban evaporation rates for water-permeable pavements.

Science.gov (United States)

Starke, P; Göbel, P; Coldewey, W G

2010-01-01

In urban areas the natural water balance is disturbed. Infiltration and evaporation are reduced, resulting in a high surface runoff and a typical city climate, which can lead to floods and damages. Water-permeable pavements have a high infiltration rate that reduces surface runoff by increasing the groundwater recharge. The high water retention capacity of the street body of up to 51 l/m(2) and its connection via pores to the surface lead to higher evaporation rates than impermeable surfaces. A comparison of these two kinds of pavements shows a 16% increase in evaporation levels of water-permeable pavements. Furthermore, the evaporation from impermeable pavements is linked directly to rain events due to fast-drying surfaces. Water-permeable pavements show a more evenly distributed evaporation after a rain event. Cooling effects by evaporative heat loss can improve the city climate even several days after rain events. On a large scale use, uncomfortable weather like sultriness or dry heat can be prevented and the urban water balance can be attenuated towards the natural.

The Reflective Cracking in Flexible Pavements

Directory of Open Access Journals (Sweden)

Pais Jorge

2013-07-01

Full Text Available Reflective cracking is a major concern for engineers facing the problem of road maintenance and rehabilitation. The problem appears due to the presence of cracks in the old pavement layers that propagate into the pavement overlay layer when traffic load passes over the cracks and due to the temperature variation. The stress concentration in the overlay just above the existing cracks is responsible for the appearance and crack propagation throughout the overlay. The analysis of the reflective cracking phenomenon is usually made by numerical modeling simulating the presence of cracks in the existing pavement and the stress concentration in the crack tip is assessed to predict either the cracking propagation rate or the expected fatigue life of the overlay. Numerical modeling to study reflective cracking is made by simulating one crack in the existing pavement and the loading is usually applied considering the shear mode of crack opening. Sometimes the simulation considers the mode I of crack opening, mainly when temperature effects are predominant.

Calibration of PMIS pavement performance prediction models.

Science.gov (United States)

2012-02-01

Improve the accuracy of TxDOTs existing pavement performance prediction models through calibrating these models using actual field data obtained from the Pavement Management Information System (PMIS). : Ensure logical performance superiority patte...

Manufacture of reconstruction-bricks in Mexico

Science.gov (United States)

Rojas-Valencia, Ma. Neftalí; Penagos, Armando Aguilar; Rojas, Denise Y. Fernández; López, Alberto López; Gálves, David Morillón

2017-12-01

In Mexico, around 33.600 tons of construction wastes are generated every day, Mexico City contributing for around tons/day, with fewer than 1.000 tons/day being sent to be recycled. For that reason the purpose of this study was to manufacture sustainable bricks, based on three types of wastes generated in the building industry: wood cutting residues, wastes from the excavation process (From Coapa and Cuautlancingo, Puebla, Mexico) and recycled aggregates. Water was added as kneading material, and Opuntia ficus-indica (mucilage) was supplemented as natural additive to improve the workability of the mixtures. Conventional firing process was substituted by drying in a solar drying chamber. Nine mixtures were prepared using 62% excavation wastes, 4% wood cutting residues and 11%, 17% and 34% recycled aggregates. These mixtures were classified in two groups depending on their granulometry: the first one denominated cementitious recycled aggregates only having granulometry from 25.4 mm, 9.52 mm to 6.35 mm to fines and the second group denominated all in one recycled aggregates having granulometry of 6.35 mm to fines. The quality of the sustainable bricks was evaluated according to compressive strength and water absorption parameters. The results of nine mixtures showed that the reconstruction-bricks manufactured with the mixture seven consisting of 9.52 mm and 6.35 mm construction residues (all in one) fines presented the highest strength values, lowest maximum initial absorption (4 g/min) compared to the norm NMX-C-037-ONNCCE-2013 which establishes that the maximum limit for walls exposed to the outside is 5 g/min. Using a solar desiccator made from construction residues, the bricks were dried in 11 days, the maximum temperature was 76 °C and the maximum solar radiation captured was 733.4 W/m2.

Adaptation of AASHTO Pavement Design Guide for Local Conditions

Energy Technology Data Exchange (ETDEWEB)

Hajek, J.J. [Applied Research Associates Inc., Toronto, ON (Canada)

2001-07-01

The methodology used to adapt the 1993 AASHTO Guide for Design of Pavement Structures to Ontario conditions was described. The guide expresses the effect of traffic loads on pavement performance using the concept of axle Load Equivalency Factors (LEF). LEF is regarded as a pavement damage factor assigned to each specific load and axle configuration. The size of LEF is related to the damage that is expected to occur from a standard load of 80 kN carried by a single axle with dual tires. The factors are summarized to yield the number of Equivalent Single Axle Loads (ESALs) a pavement is expected to sustain during its life. A summary was also provided of the additional work done to prepare for the transition to the proposed mechanistically-based 2002 AASHTO Guide. The paper focused only on the design of flexible pavements in terms of load characterization using equivalent single axle loads along with axle load spectra, below grade and material characterization, plus initial and terminal serviceability and reliability. The AASHTO Guide uses two parameters to deal with design reliability: design reliability level and overall standard deviation. Data collected on Ontario highway pavements and materials was used for assessing the design inputs. Other data was also collected from research and development studies, laboratory experiments, and from a survey of experienced pavement design engineers. The end result was a new grouping of Ontario soils for pavement design, recommended values for the resilient modulus of below grade soils, recommendations for structural layer coefficients for Ontario pavement materials and recommendations for the initial pavement serviceability based on Ontario smoothness specifications. Results of calibration and verification processes indicate that for new flexible pavements, the AASHTO-Ontario model is in good agreement with the observed results. It was recommended that the calibration and verification of the AASHTO-Ontario model should be a

Stormwater quality of spring-summer-fall effluent from three partial-infiltration permeable pavement systems and conventional asphalt pavement.

Science.gov (United States)

Drake, Jennifer; Bradford, Andrea; Van Seters, Tim

2014-06-15

This study examined the spring, summer and fall water quality performance of three partial-infiltration permeable pavement (PP) systems and a conventional asphalt pavement in Ontario. The study, conducted between 2010 and 2012, compared the water quality of effluent from two Interlocking Permeable Concrete Pavements (AquaPave(®) and Eco-Optiloc(®)) and a Hydromedia(®) Pervious Concrete pavement with runoff from an Asphalt control pavement. The usage of permeable pavements can mitigate the impact of urbanization on receiving surface water systems through quantity control and stormwater treatment. The PP systems provided excellent stormwater treatment for petroleum hydrocarbons, total suspended solids, metals (copper, iron, manganese and zinc) and nutrients (total-nitrogen and total-phosphorus) by reducing event mean concentrations (EMC) as well as total pollutant loadings. The PPs significantly reduced the concentration and loading of ammonia (NH4(+)+NH3), nitrite (NO2(-)) and organic-nitrogen (Org-N) but increased the concentration and loading of nitrate (NO3(-)). The PP systems had mixed performances for the treatment of phosphate (PO4(3-)). The PP systems increased the concentration of sodium (Na) and chloride (Cl) but EMCs remained well below recommended levels for drinking water quality. Relative to the observed runoff, winter road salt was released more slowly from the PP systems resulting in elevated spring and early-summer Cl and Na concentrations in effluent. PP materials were found to introduce dissolved solids into the infiltrating stormwater. The release of these pollutants was verified by additional laboratory scale testing of the individual pavement and aggregate materials at the University of Guelph. Pollutant concentrations were greatest during the first few months after construction and declined rapidly over the course of the study. Copyright © 2014 Elsevier Ltd. All rights reserved.

Study on Flexible Pavement Failures in Soft Soil Tropical Regions

Science.gov (United States)

Jayakumar, M.; Chee Soon, Lee

2015-04-01

Road network system experienced rapid upgrowth since ages ago and it started developing in Malaysia during the colonization of British due to its significant impacts in transportation field. Flexible pavement, the major road network in Malaysia, has been deteriorating by various types of distresses which cause descending serviceability of the pavement structure. This paper discusses the pavement condition assessment carried out in Sarawak and Sabah, Malaysia to have design solutions for flexible pavement failures. Field tests were conducted to examine the subgrade strength of existing roads in Sarawak at various failure locations, to assess the impact of subgrade strength on pavement failures. Research outcomes from field condition assessment and subgrade testing showed that the critical causes of pavement failures are inadequate design and maintenance of drainage system and shoulder cross fall, along with inadequate pavement thickness provided by may be assuming the conservative value of soil strength at optimum moisture content, whereas the exiting and expected subgrade strengths at equilibrium moisture content are far below. Our further research shows that stabilized existing recycled asphalt and base materials to use as a sub-base along with bitumen stabilized open graded base in the pavement composition may be a viable solution for pavement failures.

A new structure of permeable pavement for mitigating urban heat island.

Science.gov (United States)

Liu, Yong; Li, Tian; Peng, Hangyu

2018-09-01

The urban heat island (UHI) effect has been a great threat to human habitation, and how to mitigate this problem has been a global concern over decades. This paper addresses the cooling effect of a novel permeable pavement called evaporation-enhancing permeable pavement, which has capillary columns in aggregate and a liner at the bottom. To explore the efficiency of mitigating the UHI, bench-scale permeable pavement units with capillary columns were developed and compared with conventional permeable pavement. Criteria of capillary capacities of the column, evaporation rates, and surface temperature of the pavements were monitored under simulated rainfall and Shanghai local weather conditions. Results show the capillary column was important in increasing evaporation by lifting water from the bottom to the surface, and the evaporation-enhancing permeable pavement was cooler than a conventional permeable pavement by as much as 9.4°C during the experimental period. Moreover, the cooling effect of the former pavement could persist more than seven days under the condition of no further rainfall. Statistical analysis result reveals that evaporation-enhancing permeable pavement can mitigate the UHI effect significantly more than a conventional permeable pavement. Copyright © 2018 Elsevier B.V. All rights reserved.

Precast concrete pavement - systems and performance review

Science.gov (United States)

Novak, Josef; Kohoutková, Alena; Křístek, Vladimír; Vodička, Jan

2017-09-01

Long-term traffic restrictions belong to the key disadvantages of conventional cast-in-plane concrete pavements which have been used for technical structures such as roads, parking place and airfield pavements. As a consequence, the pressure is put on the development of such systems which have short construction time, low production costs, long-term durability, low maintenance requirements etc.. The paper presents the first step in the development of an entirely new precast concrete pavement (PCP) system applicable to airfield and highway pavements. The main objective of the review of PCP systems is to acquire a better understanding of the current systems and design methods used for transport infrastructure. There is lack of information on using PCP systems for the construction of entirely new pavements. To most extensive experience is dated back to the 20th century when hexagonal slab panels and system PAG were used in the Soviet Union for the military airfields. Since cast-in-situ pavements became more common, the systems based on precast concrete panels have been mainly utilized for the removal of damaged sections of existing structures including roads, highways etc.. Namely, it concerns Fort Miller Super Slab system, Michigan system, Uretek Stitch system and Kwik system. The presented review indicates several issues associated with the listed PCP systems and their applications to the repair and rehabilitation of existing structures. Among others, the type of manufacturing technology, particularly the position of slots for dowel bars, affects the durability and performance of the systems. Gathered information serve for the development of a new system for airfield and highway pavement construction.

Assessment of macro and micro nutrients around brick kilns agricultural environment

Directory of Open Access Journals (Sweden)

Abdul Halim Farhad Sikder

2016-03-01

Full Text Available Brick kiln is well known as one of the main sources of air pollution; however, the pollutants produced from it do not remain in the air, they ultimately fall down to the soil and pollute the surroundings, therefore, this study was carried out to assess the status of macro (N, P, K and S and micro nutrients (Fe, Mn and Zn, Cu in the agricultural environment near the brick kilns of Young Brahmaputra and Jamuna Floodplain soils. Composite soil and plant samples were collected from four distances such as 250 m, 500 m, 1000 m, and 1500 m in three different sites. Sulphur (2352–3378 mg kg−1, Zn (86–156 mg kg−1 and Cu (24.7–46.9 mg kg−1 are found in the elevated levels near brick kiln soils that is released due to burning of poor quality coal and fire woods. The alarming news is that plant uptake of S and micro nutrients in the nearest areas of the brick kilns are significantly higher than the areas far from the brick production and their concentration ranges from 23 mg kg−1 to 101 mg kg−1 for Zn, 10–41 mg kg−1 for Cu, 35–1309 mg kg−1 for Fe, 26–126 mg kg−1 for Mn and 2590–mg kg−1 for S. Data indicates both soil and plant received maximum amount of micronutrients and S concentrations within 500–1000 m distances from brick kilns. Iron and Mn concentrations vary within a permissible limit but the plant uptake is high. Nitrogen concentrations is increasing with the distance from the brick kilns in both soils and plants but no definite pattern of P and K accumulation was found. Research suggested avoiding agricultural practice nearby brick kiln soils due to micronutrient contamination in order to preserve adjoined agricultural environment.

Automation of TL brick dating by ADAM-1

International Nuclear Information System (INIS)

Cechak, T.; Gerndt, J.; Hirsl, P.; Jirousek, P.; Kubelik, M.; Musilek, L.; Kanaval, J.

2000-01-01

Thermoluminescence has become an established dating method for ceramics and more recently for bricks. Based on the experiences of the work carried out since the late 1970's at the Rathgen-Forschungslabor in Berlin on the dating of bricks from historic architecture, and after evaluating all commercially available and some individually built automated and semi-automated TL-readers, a specially adapted machine for the fine grain dating of bricks was constructed in an interdisciplinary research project, undertaken by a team recruited from three faculties of the Czech Technical University in Prague. The result is the automated TL-reader ADAM-1 (Automated Dating Apparatus for Monuments) for the dating of historic architecture. Both the specific adaptation of the technique and the necessary optimal automation have influenced the design of this TL-reader. The principle advantage of brick as opposed to ceramic TL-dating emerges from the possibility of being able to obtain both a large number of samples and an above average quantity of datable material from each sample. This, together with the specific physical and chemical conditions in a brick wall, allowed a rethinking of the traditional error calculation and thus lower error margins as those obtained when dating ceramic shards. The TL-reader must therefore be able to measure and evaluate automatically numerous samples. The annular sample holder of ADAM-1 has 60 sample positions, which allow the irradiation and evaluation of samples taken from two locations. The thirty samples from one sampling point are divided into subgroups, which are processed in various ways. Three samples serve for a rough estimate of the TL sensitivity of the brick material. Nine samples are used for the measurement of 'natural TL' of the material. A further nine samples are used for testing the sensitivity of the material to beta radiation. The last nine samples serve for the testing of the sensitivity to alpha radiation. To determine the

Solar conduction heat transfer in fired clay bricks

Energy Technology Data Exchange (ETDEWEB)

Custodio-Garcia, E.; Andres Zarate, Esteban; Cordova, Quintiliano A. [Universidad Juarez Autonoma de Tabasco, DACB, Cunduacan, Tabasco 86680 (Mexico); Sebastian, P.J.; Campos-Alvarez, J. [CIE-UNAM, 62580 Temixco, Mor 62580 (Mexico); Trevino-Palacios, Carlos G. [Instituto Nacional de Astrofisica, Optica y Electronica. A.P. 51 Y 216. Puebla 72000 (Mexico); De la O-Leon, Hugo [Universidad Juarez Autonoma de Tabasco, DAIS, Cunduacan Tab (Mexico)

2005-07-15

When somebody is interested in building a house in the year-round-hot and humid regions, faces with the decision of using modern construction block material or the traditional red fired clay brick material. We performed mechanical and thermal controlled measurements on walls made using both materials. We found that the ancient tradition of using fired clay bricks, for the weather conditions in central Tabasco, represents an excellent alternative in cost and energy savings for construction.

Durability of fired clay bricks containing granite powder

OpenAIRE

Xavier, G. C.; Saboya, F.; Maia, P. C.; Alexandre, J.

2012-01-01

Over the past few decades, hundreds of papers have been published on the benefits of including rock powder as a raw material in fired clay brick manufacture. Very little has been written, however, about the durability and long-term behaviour of the final product. As a rule, the ceramic bricks used in construction in developing countries are fired at low temperatures, which detracts from their mechanical performance. This is particularly visible in harsh environmental conditions, where weather...

Influence of Pavement on Fatigue Performance of Urban Steel Box Girder Deck

Directory of Open Access Journals (Sweden)

Zheng Zhongyue

2016-01-01

Full Text Available Based on spatial finite element analysis method, the Influence of pavement on fatigue performance of orthotropic steel deck was analyzed in terms of pavement system, asphalt pavement stiffness. The result shows that compared with asphalt pavement system, RPC pavement system can not only obviously improve the stress condition of steel bridge deck, but also significantly extend the fatigue life of steel bridge panel; Increasing the stiffness of pavement layer can obviously reduce the stress amplitude of fatigue details, especially for direct contact with the pavement.

Deterioration of jointed Portland cement concrete pavements.

Science.gov (United States)

1975-01-01

Information has been gathered regarding the performance of more than 400 lane-miles of jointed PCC interstate pavements located in five construction districts in Virginia. The factors causing pavement deterioration have been identified, the processes...

Dynamic thermal performance of alveolar brick construction system

International Nuclear Information System (INIS)

Gracia, A. de; Castell, A.; Medrano, M.; Cabeza, L.F.

2011-01-01

Highlights: → Even though U-value does not measure thermal inertia, it is the commonly used parameter. → The thermal performance analysis of buildings must include the evaluation of transient parameters. → Transient parameters of alveolar brick constructive system show good agreement with its low energy consumption. -- Abstract: Alveolar bricks are being introduced in building sector due to the simplicity of their construction system and to the elimination of the insulation material. Nevertheless, it is not clear if this new system is energetically efficient and which is its thermal behaviour. This paper presents an experimental and theoretical study to evaluate the thermal behaviour of the alveolar brick construction system, compared with a traditional Mediterranean brick system with insulation. The experimental study consists of measuring the thermal performance of four real house-like cubicles. The thermal transmittance in steady-state, also known as U-value, is calculated theoretically and experimentally for each cubicle, presenting the insulated cubicles as the best construction system, with differences around 45% in comparison to the alveolar one. On the other hand, experimental results show significantly smaller differences on the energy consumption between the alveolar and insulated construction systems during summer period (around 13% higher for the alveolar cubicle). These values demonstrate the high thermal efficiency of the alveolar system. In addition, the lack of agreement between the measured energy consumption and the calculated U-values, guides the authors to analyze the thermal inertia of the different building components. Therefore, several transient parameters, extracted from the heat transfer matrix and from experimental data, are also evaluated. It can be concluded that the alveolar brick construction system presents higher thermal inertia than the insulated one, justifying the low measured energy consumption.

THE IMPACT OF BRICK KILN OPERATION TO THE DEGRADATION OF TOPSOIL QUALITY OF AGRICULTURAL LAND

Directory of Open Access Journals (Sweden)

Md. Sirajul Islam

2015-10-01

Full Text Available Brick kiln is a big environmental issue for the agriculture of Bangladesh as it was observed that the agricultural production in the soil close to the brick kiln was lesser than the same soil far from brick kiln. The study was conducted to assess the impact of brick kiln operation to the degradation of topsoil quality at Singair of Kalihati upazila in Tangail, Bangladesh, during the period of July to December 2013. The Soil was collected from areas close to the brick fields and far from the brick fields at a depth of 0-15 cm. The Electrical Conductance (EC was found almost double in the soil samples close to the brick field than the soil samples far from brick field. The organic mattter content in the soil sample close to the brickfield was significantly lower than that of the far soil sample. The mean values of total N, available P and S were also significantly lower in the soil samples close to the brick kiln, 0.05%, 12.4, and 8.36 ppm respectively in the close soils, while 0.06%, 24.6, and 11.7 ppm respectively in the far soil. There were no significant changes observed in the other elements.

Influence of industrial solid waste addition on properties of soil-cement bricks

Directory of Open Access Journals (Sweden)

F. B. Siqueira

Full Text Available Abstract The reuse of pollutant solid wastes produced in distinct industrial activities (avian eggshell waste and welding flux slag waste as a source of alternative raw material for producing soil-cement bricks for civil construction was investigated. Soil-cement bricks containing up to 30 wt% of industrial solid waste were uniaxially pressed and cured for 28 days. Special emphasis is given on the influence of solid waste addition on the technical properties (as such volumetric shrinkage, water absorption, bulk density, durability, and compressive strength, microstructure and mineral phases of soil-cement bricks. Microstructural evolution was evaluated via confocal microscopy. The experimental results showed that the solid wastes behave as charge material and influenced both technical properties and microstructure of the soil-cement bricks. It was found that up to 15 wt% of welding flux slag waste and up to 30 wt% of avian eggshell waste could be added into the soil-cement bricks for use as building material.

Sustainable concrete pavements : a manual of practice.

Science.gov (United States)

2011-08-01

Developed as a more detailed follow-up to a 2009 briefing document, Building Sustainable Pavement with Concrete, this guide provides a clear, concise, and cohesive discussion of pavement sustainability concepts and of recommended practices for maximi...

Finite element analysis of GFRP reinforced concrete pavement under static load

Science.gov (United States)

Li, Shiping; Hu, Chunhua

2018-02-01

GFRP was more corrosion resistant than traditional reinforced, it is lightweight, high strength thermal expansion coefficient is more close to the concrete and a poor conductor of electromagnetic. Therefore, the use of GFRP to replace the traditional reinforcement in concrete pavement application has excellent practical value. This paper uses ANSYS to establish delamination and reinforcement of Pavement model and analyzed response of GFRP concrete and ordinary concrete pavement structural mechanics on effects of different factors under the action of static. The results showed that under static load, pavement surface layer presented similar changes on stress of surface layer, vertical and horizontal deformation in two kinds of pavement structure, but indicators of GFRP reinforced concrete pavement were obviously better than that of ordinary concrete pavement.

Pavement Testing Facility

Data.gov (United States)

Federal Laboratory Consortium — Comprehensive Environmental and Structural AnalysesThe ERDC Pavement Testing Facility, located on the ERDC Vicksburg campus, was originally constructed to provide an...

Configurations Of Tire Pressure On The Pavement For Commercial Vehicles: Calculation Of The ‘N’ Number And The Consequences On Pavement Performance

Directory of Open Access Journals (Sweden)

Paulo Boulos Filho

2016-07-01

Full Text Available Road traffic has a high variety of types of vehicles and cargo transported. One of the main difficulties in pavement design is forecasting the changes in traffic over time and evaluating the comparative deterioration power of the various loads with axle and tire settings and different levels of repetition. The road environment in Brazil, as we know, is the main means of the country's cargo transportation. Throughout the 1990s and 2000s the road modal accounted for over 60% of the total cargo transported in the country leaving the unbalanced Brazilian transport matrix with almost exclusive investments in such means of transportation. According to CNT 2012, which conducted a survey in approximately 45% of the paved network, evaluating the pavement functional conditions, traffic signs and geometry, 46% of the country’s road network has some type of deficiency in the pavement. The goal of this work is to contribute to a better understanding of the complex influence of traffic in the design and service life of the pavement. The load pressure of commercial vehicle tires over the pavement has increased in recent decades. A more apparent effect of this increase in tire pressure would be the change in the pavement- tire contact area which in turn may result in an increase in the contact load between tire and pavement and other harmful effects on the structure. This study aims to determine the effect on the calculation of the N number, or the number of solicitations of the standard axle on the road pavement, measuring the overload as a percentage of the legal load indicated by a scale. In short, we calculate how an increase in the overload percentage in comparison with the allowable load will influence the decrease of the calculated durability of the pavement designed for the highway.

An Innovative Cellular Automata Technique for Mapping Cracking Pattern of Airport Pavement

Directory of Open Access Journals (Sweden)

Yin Fucheng

2017-01-01

Full Text Available In this study, an innovative cellular automata (CA technique was proposed for mapping cracking pattern of the airport pavement. The CA technique was developed to establish a numerical model describing the effect of boundary condition of pavement on zones (CA cells within the pavement. A state function was used to describe the state values in the cells within the CA lattice. The correction coefficient principle is used as the criterion of zone similarity and the corresponding technique is proposed to find similar zones within and between pavements. Three pavement models, HRS, MRS and LRS, tested in FAA, USA, are set as the base pavements to map the cracking patterns of pavements with different sizes from the base pavements. The mapped cracking patterns of unseen pavements are empirically verified by referring to the relative experimental models.

An approach to pavement management in Virginia.

Science.gov (United States)

1981-01-01

The report summarizes the objectives and benefits of formal pavement management systems and outlines an approach believed by the author to be practical for Virginia. The management of Virginia interstate pavements and a proposed random-sampling plan ...

Dynamic contracting mechanism for pavement maintenance management

NARCIS (Netherlands)

Demirel, H.C.; De Ridder, H.A.J.

2013-01-01

Technological advances, financial possibilities and changes of demands have increasingly affected the pavement maintenance environment for outsourcing in recent years. This induces complexity in the contracting methods of pavement maintenance activities. Despite the fact that current contracting

Micromechanical models to guide the development of synthetic ‘brick and mortar’ composites

Science.gov (United States)

Begley, Matthew R.; Philips, Noah R.; Compton, Brett G.; Wilbrink, David V.; Ritchie, Robert O.; Utz, Marcel

2012-08-01

This paper describes a micromechanical analysis of the uniaxial response of composites comprising elastic platelets (bricks) bonded together with thin elastic perfectly plastic layers (mortar). The model yields closed-form results for the spatial variation of displacements in the bricks as a function of constituent properties, which can be used to calculate the effective properties of the composite, including elastic modulus, strength and work-to-failure. Regime maps are presented which indicate critical stresses for failure of the bricks and mortar as a function of constituent properties and brick architecture. The solution illustrates trade-offs between elastic modulus, strength and dissipated work that are a result of transitions between various failure mechanisms associated with brick rupture and rupture of the interfaces. Detailed scaling relationships are presented with the goal of providing material developers with a straightforward means to identify synthesis targets that balance competing mechanical behaviors and optimize material response. Ashby maps are presented to compare potential brick and mortar composites with existing materials, and identify future directions for material development.

Fusing complementary images for pavement cracking measurements

International Nuclear Information System (INIS)

Yao, Ming; Zhao, Zuyun; Xu, Bugao; Yao, Xun

2015-01-01

Cracking is a major pavement distress that jeopardizes road serviceability and traffic safety. Automated pavement distress survey (APDS) systems have been developed using digital imaging technology to replace human surveys for more timely and accurate inspections. Most APDS systems require special lighting devices to illuminate pavements and prevent shadows of roadside objects that distort cracks in the image. Most artificial lighting devices are laser based, and are either hazardous to unprotected people or require dedicated power supplies on the vehicle. This study was aimed to develop a new imaging system that can scan pavement surface at highway speed and determine the level of severity of pavement cracking without using any artificial lighting. The new system consists of dual line-scan cameras that are installed side by side to scan the same pavement area as the vehicle moves. Cameras are controlled with different exposure settings so that both sunlit and shadowed areas can be visible in two separate images. The paired images contain complementary details useful for reconstructing an image in which the shadows are eliminated. This paper intends to present (1) the design of the dual line-scan camera system, (2) a new calibration method for line-scan cameras to rectify and register paired images, (3) a customized image-fusion algorithm that merges the multi-exposure images into one shadow-free image for crack detection, and (4) the results of the field tests on a selected road over a long period. (paper)

Desert Pavement Studies

National Research Council Canada - National Science Library

Haff, Peter

2003-01-01

Combining plan view information from aerial photography showing details of stream channels on desert pavement surfaces with process-based erosion models, a high-resolution, synthetic topography DEM...

Desert Pavement Studies

National Research Council Canada - National Science Library

Haff, P

2003-01-01

Combining plan view information from aerial photography showing details of stream channels on desert pavement surfaces with process-based erosion models, a high-resolution, "synthetic topography" DEM...

An accelerated test method for efflorescence in clay bricks

International Nuclear Information System (INIS)

Beggan, John Edward

1998-01-01

An investigation into the creation of accelerated efflorescence in clay bricks was undertaken with a view to creating a viable test procedure for determining efflorescence potential. The testing programme incorporated ambient conditions similar to those which promote efflorescence growth in bricks in use. Theoretical investigations into the physical mechanism underlying the creation of efflorescence directed the attempts to accelerate the process. It was found that calcium sulphate efflorescence could not be sufficiently accelerated such that a useful efflorescence test procedure could be proposed. The inability to produce accelerated efflorescence in brick samples was attributed to limitations associated with time dependent salt diffusion in the efflorescence mechanism. The preliminary testing that was undertaken into the creation of efflorescence prompted the use of acid assisted methods to accelerate efflorescence. The acid assisted method that was adopted to provide a possible indication of efflorescence potential relies upon the transformation of low solubility calcium to a more soluble form. The movement of the transformed salt is then induced by cyclic temperature exposure at temperatures similar to those experienced in Spring. The appearance of the transformed calcium salt on the surface of the brick specimen provides an indication of the efflorescence potential. Brick piers constructed on an exposed site and monitored over a 12 month period provided information on the validity of the acid assisted test method. The efflorescence observed on the piers correlated well with that predicted by the acid assisted test, suggesting that the new test has the potential to accurately predict the efflorescence potential of clay bricks Relationships between other properties such as air permeability, sorptivity and tensile strength were investigated such that an alternative method of predicting efflorescence could be achieved. It was found that (within the bounds of the

Perpetual pavement – absorbing stress and functional maintenance

Directory of Open Access Journals (Sweden)

Rong Gao

2017-03-01

Full Text Available Perpetual Pavement combines the well documented smoothness and safety advantages of asphalt with an advanced, multi-layer paving design process, that with routine maintenance, extends the useful life of a roadway. Perpetual provides long lasting road and smoothness for the construction purposes. This study has the design key points of perpetual pavement based on the idea of life cycle, which has a new direction for the new highway construction, reconstruction and expansion. First, the structure of long life pavement design is studied to analyze the effect of stress absorbing layer. Second, researches on stress absorbing layer from the aspects of raw materials, mix proportion are implemented. Third, the design index of stress absorbing layer is determined by the shear strength test. The results show that the design idea of composite perpetual pavement can be realized by reasonable design of the stress absorbing layer and carrying out the surface functional maintenance can ensure the pavement to avoid structural damage in the operation stage.

Quantifying Evaporation in a Permeable Pavement System

Science.gov (United States)

Studies quantifying evaporation from permeable pavement systems are limited to a few laboratory studies and one field application. This research quantifies evaporation for a larger-scale field application by measuring the water balance from lined permeable pavement sections. Th...

Texas flexible pavements overlays : review and analysis of existing databases.

Science.gov (United States)

2011-12-01

Proper calibration of pavement design and rehabilitation performance models to : conditions in Texas is essential for cost-effective flexible pavement design. The degree of : excellence with which TxDOTs pavement design models is calibrated will d...

Pavement cracking measurements using 3D laser-scan images

International Nuclear Information System (INIS)

Ouyang, W; Xu, B

2013-01-01

Pavement condition surveying is vital for pavement maintenance programs that ensure ride quality and traffic safety. This paper first introduces an automated pavement inspection system which uses a three-dimensional (3D) camera and a structured laser light to acquire dense transverse profiles of a pavement lane surface when it carries a moving vehicle. After the calibration, the 3D system can yield a depth resolution of 0.5 mm and a transverse resolution of 1.56 mm pixel −1 at 1.4 m camera height from the ground. The scanning rate of the camera can be set to its maximum at 5000 lines s −1 , allowing the density of scanned profiles to vary with the vehicle's speed. The paper then illustrates the algorithms that utilize 3D information to detect pavement distress, such as transverse, longitudinal and alligator cracking, and presents the field tests on the system's repeatability when scanning a sample pavement in multiple runs at the same vehicle speed, at different vehicle speeds and under different weather conditions. The results show that this dedicated 3D system can capture accurate pavement images that detail surface distress, and obtain consistent crack measurements in repeated tests and under different driving and lighting conditions. (paper)

Pavement performance evaluation, phase II : data collection.

Science.gov (United States)

2008-12-01

Phase I and II of this study tested approximately 1500 rehabilitated pavements (asphalt and PCC) : throughout the State. These pavements ranged from 5 to 15 years old and were intended to develop a : snapshot of how various rehabilitations were perfo...

Comparison of winter temperature profiles in asphalt and concrete pavements.

Science.gov (United States)

2014-06-01

The objectives of this research were to 1) determine which pavement type, asphalt or concrete, has : higher surface temperatures in winter and 2) compare the subsurface temperatures under asphalt and : concrete pavements to determine the pavement typ...

Characterization of refractory brick based on local raw material from Lampung Province - Indonesia

Science.gov (United States)

Amin, Muhammad; Suryana, Yayat I.; Isnugroho, Kusno; Aji, Bramantyo B.; Birawidha, David C.; Hendronursito, Yusup

2018-04-01

Refractories are non-metallic inorganic materials that are difficult to melt at high temperatures and used in high-temperature casting industries. Refractories are classified into their constituent mineral feed stocks, refractories having typical plot properties commonly called fire bricks. In the manufacture of refractory bricks that exist in the market during the use of mangrove materials derived from abroad that is from China. In this research the refractory brick materials used are quartz sand, feldspart, kaolin, bentonite, and ball clay. All materials come from local Lampung Province - Indonesia. The experiment, there are 7 kinds of experimental composition, made of plot shape with size 230 mm, 65 mm in thickness, 114 mm height mould using manual press machine with 10 tons power and burning at 1400°C for 5 hours. Refractory brick product is done by physical test in the form of porosity, specific gravity, compressive strength and XRF and SEM characteristics. The result of XRF characteristic of refractory brick composition of 1 to 5 compared to the refractory brick type SK 34 in the market and the result of composition 1 is a composition close to refractory brick composition type SK 34 namely SiO2 is 54.21 %, Al2O3 is 25.38 % and test Physical of Bulk density is 2.25 g/cm3, porosity is 18.98 % and compressive strength is 325 kg/cm2.

Effect of speed hump characteristics on pavement condition

Directory of Open Access Journals (Sweden)

Talaat Ali Abdel-Wahed

2017-02-01

Full Text Available Speed humps are the most common type of traffic calming devices due to their low cost and easy installation. However, in many Egyptian roads, considerable number of these humps is randomly placed without proper engineering studies and justifications. Deterioration of pavement condition is observed near these humps. This paper presents a case study applied to collect and analyze visual inspection data for the reason of evaluating the impact of speed humps on pavement condition on intercity rural roads. The paper used 52 speed humps located in an intercity two-lane, two-way road that connects two cities, Tahta and Gerga, in Upper Egypt. The total length of this road is about 34 km. Pavement condition index (PCI, in road sections, near speed humps in the two directions of travel were calculated from the visual inspection measurements. The characteristics of each speed hump (width, height, and distance from preceding hump were measured. Using statistical analyses, the correlations between the pavement conditions and hump characteristics were examined. Regression analysis models were developed to represent the relationships between pavement conditions and hump characteristics. Generally, the results proved that the pavement conditions are greatly influenced by the presence of speed humps and hump characteristics.

Hydrogen fluoride damage to vegetation from peri-urban brick kilns in Asia: A growing but unrecognised problem?

International Nuclear Information System (INIS)

Ahmad, Muhammad Nauman; Berg, Leon J.L. van den; Shah, Hamid Ullah; Masood, Tariq; Büker, Patrick; Emberson, Lisa; Ashmore, Mike

2012-01-01

The rapid urbanisation of many cities in south and south-east Asia has increased the demand for bricks, which are typically supplied from brick kilns in peri-urban areas. We report visible foliar damage to mango, apricot and plum trees in the vicinity of traditional Bull’s Trench brick kilns in Peshawar, Pakistan. Visible injury symptoms, hydrogen fluoride concentrations in air, and foliar fluoride concentrations were all greater in the vicinity of brick kilns than at more distant sites, indicating that fluoride emissions from brick kilns were the main cause of damage. Interviews with local farmers established the significant impact of this damage on their livelihoods. Since poorly regulated brick kilns are often found close to important peri-urban agricultural areas, we suggest that this may be a growing but unrecognised environmental problem in regions of Asia where emission control in brick kilns has not been improved. - Highlights: ► Demand for bricks is increasing in many parts of Asia. ► Fluoride emissions from brick kilns may pose a threat to peri-urban agriculture. ► We found extensive injury to fruit orchards close to brick kilns in Peshawar. ► Local farmers suffered large economic losses but did not identify brick kilns as a cause of this. ► The extent of crop damage from brick kilns with poor emission control in the region may not be fully recognised. - Hydrogen fluoride emissions from brick kilns may cause extensive but unrecognised damage to peri-urban crops in Asia.

Modelling Flexible Pavement Response and Performance

DEFF Research Database (Denmark)

Ullidtz, Per

This textbook is primarily concerned with models for predicting the future condition of flexible pavements, as a function of traffic loading, climate, materials, etc., using analytical-empirical methods.......This textbook is primarily concerned with models for predicting the future condition of flexible pavements, as a function of traffic loading, climate, materials, etc., using analytical-empirical methods....

Load Response Analysis of Asphalt Pavement

Directory of Open Access Journals (Sweden)

Xiao Zhijun

2016-01-01

Full Text Available Based on the filed data of Fuzhou test road, load response regulation of nonlinear pavement structure was analyzed in this paper; Mechanics software was adopted to analyze linear elastic and nonlinear of the pavement structure, analyzed results and road filed data were compared, and determine the correlation between them and the field data.

Screening of waste for use in clay-based bricks in the Arctic

DEFF Research Database (Denmark)

Belmonte, Louise Josefine; Ottosen, Lisbeth M.; Kirkelund, Gunvor Marie

2014-01-01

Clay-based ceramics, such as bricks, are heterogeneous materials, which can incorporate raw materials ofwide ranging compositions, without impairing their technical properties (Dondi et al., 1997a,b). Due to thisability, bricks have become a popular material in waste management research worldwide...... and several studies have demonstrated that clay-based bricks and tiles can successfully accommodate waste types,such as incineration ashes, mine tailings and dredged harbour sediments (Zhang et al., 2011; Roy et al.,2007; Mezencevova et al., 2012). In the vulnerable Arctic environment, the impact...... a strong tradition for masonry structures. In Greenland, for example, bricks are neither currently produced locally nor frequently appliedfor construction purposes. Recent studies have, however, established that deposits of marine glaciogeneclay, which are found throughout the former glaciated areas...

Study on road surface source pollution controlled by permeable pavement

Science.gov (United States)

Zheng, Chaocheng

2018-06-01

The increase of impermeable pavement in urban construction not only increases the runoff of the pavement, but also produces a large number of Non-Point Source Pollution. In the process of controlling road surface runoff by permeable pavement, a large number of particulate matter will be withheld when rainwater is being infiltrated, so as to control the source pollution at the source. In this experiment, we determined the effect of permeable road surface to remove heavy pollutants in the laboratory and discussed the related factors that affect the non-point pollution of permeable pavement, so as to provide a theoretical basis for the application of permeable pavement.

Development of Interlocking Masonry Bricks and its’ Structural Behaviour: A Review Paper

Science.gov (United States)

Al-Fakih, Amin; Mohammed, Bashar S.; Nuruddin, Fadhil; Nikbakht, Ehsan

2018-04-01

Conventional bricks are the most elementary building materials for houses construction. However, the rapid growth in today’s construction industry has obliged the civil engineers in searching for a new building technique that may result in even greater economy, more efficient and durable as an alternative for the conventional brick. Moreover, the high demands for having a speedy and less labour and cost building systems is one of the factor that cause the changes of the masonry conventional systems. These changes have led to improved constructability, performance, and cost as well. Several interlocking bricks has been developed and implemented in building constructions and a number of researches had studied the manufacturing of interlocking brick and its structural behaviour as load bearing and non-load bearing element. This technical paper aims to review the development of interlocking brick and its structural behaviour. In conclusion, the concept of interlocking system has been widely used as a replacement of the conventional system where it has been utilized either as load bearing or non-load bearing masonry system.

Experimental pavement delineation treatments

Science.gov (United States)

Bryden, J. E.; Lorini, R. A.

1981-06-01

Visibility and durability of materials used to delineate shoulders and medians adjacent to asphalt pavements were evaluated. Materials evaluated were polysulfide and coal tar epoxies, one and two component polyesters, portland cement, acrylic paints, modified-alkyd traffic paint, preformed plastic tape, and thermoplastic markings. Neat applications, sand mortars, and surface treatments were installed in several geometric patterns including cross hatches, solid median treatments, and various widths of edge lines. Thermoplastic pavement markings generally performed very well, providing good visibility under adverse viewing conditions for at least 4 years. Thermoplastic 4 in. wide edge lines appear to provide adequate visibility for most conditions.

Applications of waste material in the pervious concrete pavement: A review

Science.gov (United States)

Shakrani, Shahrul Azwan; Ayob, Afizah; Rahim, Mohd Asri Ab

2017-09-01

Pervious concrete pavement is one of the innovative structures designed in order to manage the quantity and quality of urban stormwater for a sustainable development. In general, pervious concrete pavement enables water to permeate through its structure and have a capability to cater dynamic loads at the same time. However, the conventional pervious concrete pavement lacks a superior strength while performing as pavement structure. Thus, an extensive research has been carried out in order to explore the possible materials to be incorporated into the pervious concrete pavement for better physical, structural and mechanical properties. The objectives of this paper are to review the waste materials used in the pervious concrete pavement along with their mechanical, durability and permeability performance.

Dynamic Modeling of Pavements with Application to Deflection Measurements

DEFF Research Database (Denmark)

Madsen, Stine Skov

Pavement surface deflection measurements are the primary means of evaluating the bearing capacity of a pavement. The most common type of device used for measuring pavement surface deflections is the Falling Weight Deflectometer (FWD). However, increasing attention has been given to the Rolling Wheel...... Deflectometer (RWD) type of device due to its ability to measure deflections continuously while driving at traffic speed. To be able to properly interpret deflection measurements from an RWD device, more knowledge about the structural behavior of a pavement when subjected to transient dynamic loads moving...

Processes of Fatigue Destruction in Nanopolymer-Hydrophobised Ceramic Bricks

Directory of Open Access Journals (Sweden)

Stanisław Fic

2017-01-01

Full Text Available The article presents a proposal of a model of fatigue destruction of hydrophobised ceramic brick, i.e., a basic masonry material. The brick surface was hydrophobised with two inorganic polymers: a nanopolymer preparation based on dialkyl siloxanes (series 1–5 and an aqueous silicon solution (series 6–10. Nanosilica was added to the polymers to enhance the stability of the film formed on the brick surface. To achieve an appropriate blend of the polymer liquid phase and the nano silica solid phase, the mixture was disintegrated by sonication. The effect of the addition of nano silica and sonication on changes in the rheological parameters, i.e., viscosity and surface tension, was determined. Material fatigue was induced by cyclic immersion of the samples in water and drying at a temperature of 100 °C, which caused rapid and relatively dynamic movement of water. The moisture and temperature effect was determined by measurement of changes in surface hardness performed with the Vickers method and assessment of sample absorbability. The results provided an approximate picture of fatigue destruction of brick and hydrophobic coatings in relation to changes in their temporal stability. Additionally, SEM images of hydrophobic coatings in are shown.

Long-Term Field Performance of Pervious Concrete Pavement

Directory of Open Access Journals (Sweden)

Aleksandra Radlińska

2012-01-01

Full Text Available The work described in this paper provides an evaluation of an aged pervious concrete pavement in the Northeastern United States to provide a better understanding of the long-lasting effects of placement techniques as well as the long-term field performance of porous pavement, specifically in areas susceptible to freezing and thawing. Multiple samples were taken from the existing pavement and were examined in terms of porosity and unit weight, compressive and splitting tensile strength, and the depth and degree of clogging. It was concluded that improper placement and curing led to uneven pavement thickness, irregular pore distribution within the pervious concrete, and highly variable strength values across the site, as well as sealed surfaces that prevented infiltration.

Use of demolition residues construction in soil-lime bricks

International Nuclear Information System (INIS)

Figueiredo, S.S.; Silva, C.G.; Silva, I.A.; Neves, G.A.

2011-01-01

Besides being responsible for several environmental damage caused by its residues, the construction industry is also considered the greatest natural resources consumer. When finely ground, such residues can exhibit cementing properties, which may replace part of the lime used in the manufacture of soil-lime bricks. This study aimed to verify the viability of using demolition residues (DR) in soil-lime bricks without structural function. For this, test specimens were prepared using mixes in a 1:10 ratio of lime:soil and embedding residue in partial replacement of lime in the proportions of 25%, 50% and 75%. The test specimens were submitted to curing periods of 28 and 52 days, then it was determined the compression strength. The results showed that when embedded on moderate percentages, demolition residues construction can be used in the production of soil-lime bricks. (author)

Dredged sediments as a resource for brick production: Possibilities and barriers from a consumers’ perspective

International Nuclear Information System (INIS)

Cappuyns, Valérie; Deweirt, Valentine; Rousseau, Sandra

2015-01-01

Highlights: • Consumers are suspicious towards bricks produced from dredged sediments. • Technical quality, safety and environmental impacts are considered key characteristics. • Public has insufficient knowledge on bricks produced from dredged sediments. • Sensitization and provision of information to customers are of primary importance. - Abstract: A possible solution for the oversupply of dredged sediments is their use as a raw material in brick production. Despite the fact that several examples (e.g., Agostini et al., 2007; Hamer and Karius, 2002; Xu et al., 2014) show that this application is feasible, some economic, technical and social limitations interfere with the development of a market of dredged materials in brick production in Flanders. While we describe the main characteristics of the supply side, we focus on the limitations and barriers from the demand side in the present study. Based on a consumers survey we analyze consumers’ risk perceptions and attitudes towards bricks produced from dredged sediments. Consumers in Flanders are rather suspicious with respect to bricks produced from dredged sediments and their risk perception is mainly determined by the possibility of a bad bargain (brick of inferior quality) and the connotation with chemical contamination. The willingness to pay for bricks made from dredged sediments is mainly influenced by the age of the respondents, as well environmental awareness, and the respondents’ belief in their ability to influence environmental problems. Sensitization and information of customers seems to be of primary importance to make dredged-sediment-derived bricks a successful product

Dredged sediments as a resource for brick production: Possibilities and barriers from a consumers’ perspective

Energy Technology Data Exchange (ETDEWEB)

Cappuyns, Valérie, E-mail: valerie.cappuyns@kuleuven.be; Deweirt, Valentine; Rousseau, Sandra

2015-04-15

Highlights: • Consumers are suspicious towards bricks produced from dredged sediments. • Technical quality, safety and environmental impacts are considered key characteristics. • Public has insufficient knowledge on bricks produced from dredged sediments. • Sensitization and provision of information to customers are of primary importance. - Abstract: A possible solution for the oversupply of dredged sediments is their use as a raw material in brick production. Despite the fact that several examples (e.g., Agostini et al., 2007; Hamer and Karius, 2002; Xu et al., 2014) show that this application is feasible, some economic, technical and social limitations interfere with the development of a market of dredged materials in brick production in Flanders. While we describe the main characteristics of the supply side, we focus on the limitations and barriers from the demand side in the present study. Based on a consumers survey we analyze consumers’ risk perceptions and attitudes towards bricks produced from dredged sediments. Consumers in Flanders are rather suspicious with respect to bricks produced from dredged sediments and their risk perception is mainly determined by the possibility of a bad bargain (brick of inferior quality) and the connotation with chemical contamination. The willingness to pay for bricks made from dredged sediments is mainly influenced by the age of the respondents, as well environmental awareness, and the respondents’ belief in their ability to influence environmental problems. Sensitization and information of customers seems to be of primary importance to make dredged-sediment-derived bricks a successful product.

Long term pavement performance computed parameter : frost penetration

Science.gov (United States)

2008-11-01

As the pavement design process moves toward mechanistic-empirical techniques, knowledge of seasonal changes in pavement structural characteristics becomes critical. Specifically, frost penetration information is necessary for determining the effect o...

Excitonic AND Logic Gates on DNA Brick Nanobreadboards

Science.gov (United States)

2015-01-01

A promising application of DNA self-assembly is the fabrication of chromophore-based excitonic devices. DNA brick assembly is a compelling method for creating programmable nanobreadboards on which chromophores may be rapidly and easily repositioned to prototype new excitonic devices, optimize device operation, and induce reversible switching. Using DNA nanobreadboards, we have demonstrated each of these functions through the construction and operation of two different excitonic AND logic gates. The modularity and high chromophore density achievable via this brick-based approach provide a viable path toward developing information processing and storage systems. PMID:25839049

Feasibility of perpetual pavement stage construction in China: A life cycle cost analysis

Directory of Open Access Journals (Sweden)

Zhongyin Guo

2016-12-01

Full Text Available The main objective of pavement design and management is to build sustainable pavement structure with minimum costs during its whole life. There are many uncertainties in the process of pavement design pertaining many of its variables, such as future traffic estimation, long time behavior of materials, future weights and types of traveling vehicles, availability of funds etc. Therefore, it is important to apply pavement stage construction technique during the process of pavement design and management to minimize the risk associated with these uncertainties. From the beginning of 2000, the research and application of perpetual asphalt pavement (PP technology has been deployed in China. The semi rigid base for asphalt pavement has been normally considered as typical component of high class highways in the design according to the Chinese experience since 1997. The research objective is to apply pavement stage construction for the evaluation of life cycle costs of Chinese perpetual and traditional semi rigid pavements using operational pavement management system in addition to examine its suitability for design and construction of more economical and durable flexible pavements. It has been found that the stage construction of asphalt layers in PP over semi rigid pavement foundation will create more sustainable and trusted pavement structures in spite of 2–5% increase in present total cost.

Heat and Moisture Transport and Storage Parameters of Bricks Affected by the Environment

Science.gov (United States)

Kočí, Václav; Čáchová, Monika; Koňáková, Dana; Vejmelková, Eva; Jerman, Miloš; Keppert, Martin; Maděra, Jiří; Černý, Robert

2018-05-01

The effect of external environment on heat and moisture transport and storage properties of the traditional fired clay brick, sand-lime brick and highly perforated ceramic block commonly used in the Czech Republic and on their hygrothermal performance in building envelopes is analyzed by a combination of experimental and computational techniques. The experimental measurements of thermal, hygric and basic physical parameters are carried out in the reference state and after a 3-year exposure of the bricks to real climatic conditions of the city of Prague. The obtained results showed that after 3 years of weathering the porosity of the analyzed bricks increased up to five percentage points which led to an increase in liquid and gaseous moisture transport parameters and a decrease in thermal conductivity. Computational modeling of hygrothermal performance of building envelopes made of the studied bricks was done using both reference and weather-affected data. The simulated results indicated an improvement in the annual energy balances and a decrease in the time-of-wetness functions as a result of the use of data obtained after the 3-year exposure to the environment. The effects of weathering on both heat and moisture transport and storage parameters of the analyzed bricks and on their hygrothermal performance were found significant despite the occurrence of warm winters in the time period of 2012-2015 when the brick specimens were exposed to the environment.

Variability of Pavement Distress Data From Manual Surveys

OpenAIRE

Daleiden, Jerome

2014-01-01

Functional Session 5: Pavement Management Moderated by Akyiaa Hosten This presentation was held at the Pavement Evaluation 2014 Conference, which took place from September 15-18, 2014 in Blacksburg, Virginia. Presentation only

Effect of age of permeable pavements on their infiltration function

NARCIS (Netherlands)

Boogaard, Floris; Lucke, Terry; Beecham, Simon

This study describes field investigations designed to compare the infiltration capacities of 55 permeable pavement systems installed in the Netherlands and in Australia. The ages of the pavements varied from 1 to 12 years. Using infiltrometer testing, the performance of the pavements has been

Effect of age of permeable pavements on their infiltration function

NARCIS (Netherlands)

Terry Lucke; ir. Floris Boogaard; Simon Beecham

2013-01-01

This study describes field investigations designed to compare the infiltration capacities of 55 permeable pavement systems installed in the Netherlands and in Australia. The ages of the pavements varied from 1 to 12 years. Using infiltrometer testing, the performance of the pavements has been

Influence of pavement condition on horizontal curve safety.

Science.gov (United States)

Buddhavarapu, Prasad; Banerjee, Ambarish; Prozzi, Jorge A

2013-03-01

Crash statistics suggest that horizontal curves are the most vulnerable sites for crash occurrence. These crashes are often severe and many involve at least some level of injury due to the nature of the collisions. Ensuring the desired pavement surface condition is one potentially effective strategy to reduce the occurrence of severe accidents on horizontal curves. This study sought to develop crash injury severity models by integrating crash and pavement surface condition databases. It focuses on developing a causal relationship between pavement condition indices and severity level of crashes occurring on two-lane horizontal curves in Texas. In addition, it examines the suitability of the existing Skid Index for safety maintenance of two-lane curves. Significant correlation is evident between pavement condition and crash injury severity on two-lane undivided horizontal curves in Texas. Probability of a crash becoming fatal is appreciably sensitive to certain pavement indices. Data suggested that road facilities providing a smoother and more comfortable ride are vulnerable to severe crashes on horizontal curves. In addition, the study found that longitudinal skid measurement barely correlates with injury severity of crashes occurring on curved portions. The study recommends exploring the option of incorporating lateral friction measurement into Pavement Management System (PMS) databases specifically at curved road segments. Copyright © 2012 Elsevier Ltd. All rights reserved.

The leaf phenophase of deciduous species altered by land pavements

Science.gov (United States)

Chen, Yuanyuan; Wang, Xiaoke; Jiang, Bo; Li, Li

2018-02-01

It has been widely reported that the urban environment alters leaf and flowering phenophases; however, it remains unclear if land pavement is correlated with these alterations. In this paper, two popular deciduous urban trees in northern China, ash (Fraxinus chinensis) and maple (Acer truncatum), were planted in pervious and impervious pavements at three spacings (0.5 m × 0.5 m, 1.0 m × 1.0 m, and 2.0 m × 2.0 m apart). The beginning and end dates of the processes of leaf budburst and senescence were recorded in spring and fall of 2015, respectively. The results show that leaf budburst and senescence were significantly advanced in pavement compared to non-pavement lands. The date of full leaf budburst was earlier by 0.7-9.3 days for ash and by 0.3-2.3 days for maple under pavements than non-pavements, respectively. As tree spacing increases, the advanced days of leaf budburst became longer. Our results clearly indicate that alteration of leaf phenophases is attributed to land pavement, which should be taken into consideration in urban planning and urban plant management.

Incorporating moving dynamic tyre loads in pavement design and analysis

CSIR Research Space (South Africa)

Steyn, WJvdM

2000-07-01

Full Text Available at the University of Pretoria. 4 REAL LIFE TYRE LOADS Characterisation Pavement loading has been shown by various authors to be a dynamic (time-dependent) phenomenon (Divine, 1997; Cebon, 1999). A pavement experiences a vehicle as a moving, time-varying set... frequencies. Body bounce generally dominates the dynamic loading, and is mainly caused by the response of the sprung mass of the vehicle to the pavement roughness. Axle hop becomes more significant at higher vehicle speeds and higher pavement roughnesses...

Respiratory Abnormalities among Occupationally Exposed, Non-Smoking Brick Kiln Workers from Punjab, India.

Science.gov (United States)

Tandon, Supriya; Gupta, Sharat; Singh, Sharanjeet; Kumar, Avnish

2017-07-01

Brick manufacturing industry is one of the oldest and fast-growing industries in India that employs a large section of people. Brick kiln workers are occupationally exposed to air pollutants. Nonetheless, only a few studies have so far been conducted on their respiratory health. To investigate the extent of respiratory impairment in brick kiln workers and to correlate it with the duration of exposure. A cross-sectional study was conducted. Spirometric parameters of 110 non-smoking male brick kiln workers aged 18-35 years in Patiala district, Punjab, India, were compared with an age-matched comparison group of 90 unexposed individuals. Brick kiln workers showed a significant (pworkers was associated with the duration of exposure. In workers with >8 years of exposure, the mean values of FEV 1 (1.92 L), FVC (2.01 L), FEF 25-75% (2.19 L/s) and PEFR (4.81 L/s) were significantly (pworkers with workers.

Landfill gas powers brick production

International Nuclear Information System (INIS)

CADDET UK National Team.

1997-01-01

Marshalls plc produce high-quality facing bricks using tunnel kilns at the company's Stairfoot Brickworks site, in the UK. The company extracts clay from the adjacent quarries, which are subsequently filled with domestic waste. In 1981 Marshalls decided to exploit the landfill gas (LFG) resource 'on its doorstep'. (author)

Investigation on dynamical interaction between a heavy vehicle and road pavement

Science.gov (United States)

Yang, Shaopu; Li, Shaohua; Lu, Yongjie

2010-08-01

This paper presents a model for three-dimensional, heavy vehicle-pavement-foundation coupled system, which is modelled as a seven-DOF vehicle moving along a simply supported double-layer rectangular thin plate on a linear viscoelastic foundation. The vertical tyre force is described by a single point-contact model, while the pavement-foundation is modelled as a double-layer plate on a linear viscoelastic foundation. Using the Galerkin method and quick direct integral method, the dynamical behaviour of the vehicle-pavement-foundation coupled system is investigated numerically and compared with that of traditional vehicle system and pavement system. The effects of coupling action on vehicle body vertical acceleration, suspension deformations, tyre forces and pavement displacements are also obtained. The investigation shows that the coupling action could not be neglected even on a smooth road surface, such as highway. Thus, it is necessary to investigate the dynamics of vehicle and pavement simultaneously based on the vehicle-pavement-foundation coupled system.

Management of spent shea waste: An instrumental characterization and valorization in clay bricks construction.

Science.gov (United States)

Adazabra, A N; Viruthagiri, G; Shanmugam, N

2017-06-01

This work studies the reuse of spent shea waste as an economic construction material in improving fired clay bricks manufacture aside providing a novel approach to ecofriendly managing its excessive generated from the shea agroindustry. For this purpose, the influence of spent shea waste addition on the chemical, mineralogical, molecular bonding and technological properties (i.e. compressive strength and water absorption) of the fired clay bricks were extensively investigated. The results indicated that the chemical, mineralogical, phase transformations, molecular bonding and thermal behavior of the produced bricks were practically unaffected by the addition of spent shea waste. However, spent shea waste addition increased the compressive strengths and water absorptions of the brick products. Potential performance benefits of reusing spent shea waste was improved fluxing agents, energy-contribution reaction, excellent porosifying effect, reduced thermal conductivity and enhanced compressive strengths of the brick products. This research has therefore provided compelling evidence that could create newfound route for the synergistic ecofriendly reuse of spent shea waste to enhance clay brick construction aside being a potential mainstream disposal option. Copyright © 2017 Elsevier Ltd. All rights reserved.

Pavement Response to Variable Tyre Pressure of Heavy Vehicles

Directory of Open Access Journals (Sweden)

Arshad Ahmad Kamil

2016-01-01

Full Text Available In recent years, the effect of overinflated tyre pressure and increased heavy vehicles’ axle load on flexible pavements has become a subject of great concern because of the higher stress levels induced and damage caused to road pavements. This paper aims to evaluate the effect of variable tyre inflation pressures (using actual tyre contact/footprint area to determine the responses of flexible pavement. A full scale experiment was conducted on a heavy vehicle with 1:1:2 axle configuration, 10 R 20 tyre size and attached trailer with constant axle load. Measurements were made for actual tyre-pavement contact area. KENPAVE linear elastic program was then used to analyse the effects of the measured actual tyre-pavement contact area and the results was compared using conventional circular tyre contact area. A comparative analysis was then made between the actual contact area and the conventional circular tyre contact area. It was found that high tyre inflation pressure produce smaller contact area, giving more detrimental effect on the flexible pavement. It was also found that the temperature of tyres when the heavy vehicles are operational give less significant impact on tyre inflation pressure for the Malaysian climate.

Implementation of a pavement management system in Virginia.

Science.gov (United States)

1987-01-01

The report summarizes the developments in pavement management in the Virginia Department of Transportation through late 1986. Included are discussions of the pavement management process with examples of priority programming, long-range projection of ...

Tyre-pavement interface contact stresses on flexible pavements - quo vadis?

CSIR Research Space (South Africa)

De Beer, Morris

2004-09-01

Full Text Available on tyre inflation pressure on this route is also given. The paper also discusses an improved definition of the actual tyre/pavement interaction of modern heavy vehicles and their loads on the current flexible road infrastructure....

Inventorying Toronto's single detached housing stocks to examine the availability of clay brick for urban mining.

Science.gov (United States)

Ergun, Deniz; Gorgolewski, Mark

2015-11-01

This study examines the stocks of clay brick in Toronto's single detached housing, to provide parameters for city scale material reuse and recycling. Based on consensus from the literature and statistics on Toronto's single detached housing stocks, city scale reusable and recyclable stocks were estimated to provide an understanding of what volume could be saved from landfill and reintroduced into the urban fabric. On average 2523-4542 m(3) of brick was determined to be available annually for reuse, which would account for 20-36% of the volume of virgin brick consumed in new house construction in 2012. A higher volume, 6187 m(3) of brick, was determined to be available annually for recycling because more of the prevalence of cement-based mortar, which creates challenges for brick reuse in Toronto. The results demonstrated that older housing containing reusable brick were being mostly landfilled and replaced with housing that contained only recyclable brick. Copyright © 2015 Elsevier Ltd. All rights reserved.

Assessing the role of pavement macrotexture in preventing crashes on highways.

Science.gov (United States)

Pulugurtha, Srinivas S; Kusam, Prasanna R; Patel, Kuvleshay J

2010-02-01

The objective of this article is to assess the role of pavement macrotexture in preventing crashes on highways in the State of North Carolina. Laser profilometer data obtained from the North Carolina Department of Transportation (NCDOT) for highways comprising four corridors are processed to calculate pavement macrotexture at 100-m (approximately 330-ft) sections according to the American Society for Testing and Materials (ASTM) standards. Crash data collected over the same lengths of the corridors were integrated with the calculated pavement macrotexture for each section. Scatterplots were generated to assess the role of pavement macrotexture on crashes and logarithm of crashes. Regression analyses were conducted by considering predictor variables such as million vehicle miles of travel (as a function of traffic volume and length), the number of interchanges, the number of at-grade intersections, the number of grade-separated interchanges, and the number of bridges, culverts, and overhead signs along with pavement macrotexture to study the statistical significance of relationship between pavement macrotexture and crashes (both linear and log-linear) when compared to other predictor variables. Scatterplots and regression analysis conducted indicate a more statistically significant relationship between pavement macrotexture and logarithm of crashes than between pavement macrotexture and crashes. The coefficient for pavement macrotexture, in general, is negative, indicating that the number of crashes or logarithm of crashes decreases as it increases. The relation between pavement macrotexture and logarithm of crashes is generally stronger than between most other predictor variables and crashes or logarithm of crashes. Based on results obtained, it can be concluded that maintaining pavement macrotexture greater than or equal to 1.524 mm (0.06 in.) as a threshold limit would possibly reduce crashes and provide safe transportation to road users on highways.

Utilization of Yatagan Power Plant Fly Ash in Production of Building Bricks

Science.gov (United States)

Önel, Öznur; Tanriverdi, Mehmet; Cicek, Tayfun

2017-12-01

Fly ash is a by-product of coal combustion, which accumulates in large quantities near the coal-fired power plants as waste material. Fly ash causes serious operational and environmental problems. In this study, fly ash from Yatağgan thermal power plant was used to produce light-weight building bricks. The study aimed to reduce the problems related to fly ash by creating a new area for their use. The optimum process parameters were determined for the production of real size bricks to be used in construction industry. The commercial size bricks (200 × 200 × 90-110 mm) were manufactured using pilot size equipment. Mechanical properties, thermal conductivity coefficients, freezing and thawing strengths, water absorption rates, and unit volume weights of the bricks were determined. Etringite (Ca6Al2 (SO4)3 (OH)12 25(H2O)) and Calcium Silicate Hydrate (2CaO.SiO2.4H2O) were identified as the binding phases in the real size brick samples after 2 days of pre-curing and 28 days curing at 50° C and 95% relative moisture. The water absorption rate was found to be 27.7 % in terms of mass. The mechanical and bending strength of the brick samples with unit volume weight of 1.29 g.cm-3 were determined as 6.75 MPa and 1,56 MPa respectively. The thermal conductivity of the fly ash bricks was measured in average as 0,340 W m-1 K-1. The fly ash sample produced was subjected to toxic leaching tests (Toxic Property Leaching Procedure (EPA-TCLP 1311), Single-step BATCH Test and Method-A Disintegration Procedure (ASTM)). The results of these tests suggested that the materials could be classified as non-hazardous wastes / materials.

Modified pavement cement concrete

Science.gov (United States)

Botsman, L. N.; Ageeva, M. S.; Botsman, A. N.; Shapovalov, S. M.

2018-03-01

The paper suggests design principles of pavement cement concrete, which covers optimization of compositions and structures at the stage of mixture components selection due to the use of plasticizing agents and air-retaining substances that increase the viability of a concrete mixture. It also demonstrates advisability of using plasticizing agents together with air-retaining substances when developing pavement concrete compositions, which provides for the improvement of physical and mechanical properties of concrete and the reduction of cement binding agent consumption thus preserving strength indicators. The paper shows dependences of the main physical-mechanical parameters of concrete on cement consumption, a type and amount of additives.

Optical microtopographic inspection of asphalt pavement surfaces

Science.gov (United States)

Costa, Manuel F. M.; Freitas, E. F.; Torres, H.; Cerezo, V.

2017-08-01

Microtopographic and rugometric characterization of surfaces is routinely and effectively performed non-invasively by a number of different optical methods. Rough surfaces are also inspected using optical profilometers and microtopographer. The characterization of road asphalt pavement surfaces produced in different ways and compositions is fundamental for economical and safety reasons. Having complex structures, including topographically with different ranges of form error and roughness, the inspection of asphalt pavement surfaces is difficult to perform non-invasively. In this communication we will report on the optical non-contact rugometric characterization of the surface of different types of road pavements performed at the Microtopography Laboratory of the Physics Department of the University of Minho.

Renewable energies for the production of bricks

International Nuclear Information System (INIS)

Moedinger, F.

2006-01-01

The research for alternatives to the classical, mainly fossil, sources of energy sources within a high energy consumption sector as brick making can certainly be very rewarding. Within this framework the production of biogas by anaerobic digestion of locally available biomasses and the integration of such a facility in a brick yard where all fermentation wastes, both liquid and solid, can be used can be considered a strategic and profitable business goal: reduction of the dependence on fossil fuels. From an environmental point of view the substitution of fossil fuels with fuels from renewable sources is certainly desire able. Into account might also be taken the possible profitable trade of emission certificates of different type

Full scale demonstration of air-purifying pavement

NARCIS (Netherlands)

Ballari, M.; Brouwers, H.J.H.

2013-01-01

Experiments concerning a full-scale demonstration of air purifying pavement in Hengelo, The Netherlands, are reported. The full width of the street was provided with concrete pavement containing TiO2 over a length of 150 m ("DeNOx street"). Another part of the street, about 100 m, was paved with

75 FR 21346 - Certain Magnesia Carbon Bricks From China and Mexico

Science.gov (United States)

2010-04-23

...)] Certain Magnesia Carbon Bricks From China and Mexico AGENCY: United States International Trade Commission... of subsidized imports from China or less-than-fair-value imports from China or Mexico of certain... bricks from China and Mexico are being sold in the United States at less than fair value within the...

Assessing Asphalt and Concrete Pavement Surface Texture in the Field

Directory of Open Access Journals (Sweden)

Saad I. Sarsam

2016-06-01

Full Text Available The incorporation of safety characteristics into the traditional pavement structural design or in the functional evaluation of pavement condition has not been established yet. The design has focused on the structural capacity of the roadway so that the pavement can withstand specific level of repetitive loading over the design life. On the other hand, the surface texture condition was neither included in the AASHTO design procedure nor in the present serviceability index measurements. The pavement surface course should provide adequate levels of friction and ride quality and maintain low levels of noise and roughness. Many transportation departments perform routine skid resistant testing, the type of equipment used for testing varies depending on the preference of each transportation department. It was felt that modeling of the surface texture condition using different methods of testing may assist in solving such problem. In this work, Macro texture and Micro texture of asphalt and cement concrete pavement surface have been investigated in the field using four different methods (The Sand Patch Method, Outflow Time Method, British Pendulum Tester and Photogrammetry Technique. Two different grain sizes of sand have been utilized in conducting the Sand Patch while the Micro texture was investigated using the British Pendulum tester method at wet pavement surface conditions. The test results of the four methods were correlated to the skid number. It was concluded that such modeling could provide instant data in the field for pavement condition which may help in pavement maintenance management.

On-board sound intensity tire-pavement noise study in North Carolina.

Science.gov (United States)

2011-12-01

"This research investigated tire-pavement noise on various types of pavements across North Carolina by using On- : Board Sound Intensity (OBSI) method. To mitigate traffic noise, quieter pavement may provide advantages that : noise barriers cannot. T...

Predicting pavement condition index using international roughness index in Washington DC.

Science.gov (United States)

2014-09-01

A number of pavement condition indices are used to conduct pavement management assessments, two of which are the : International Roughness Index (IRI) and Pavement Condition Index (PCI). The IRI is typically measured using specialized : equipment tha...

The comparisons of computational models of pavement due to the dynamic load act

Directory of Open Access Journals (Sweden)

Valašková Veronika

2017-01-01

Full Text Available Finite element method (FEM is frequently used to solve current problems of the structural mechanics in engineering practice. The dynamic interaction of the two systems is one of the topics that can be solved using FEM. To simplify the solution of the interaction, it is possible to divide the system in two independent subsystems, vehicle and pavement. Computing software ADINA, based on the principles of the finite element modelling, was adopted to solve the given problem. The results from the first computational model can be used as the inputs for the second model. To analyse stress state of the pavement with different composition, three specific types of pavements were selected – concrete pavement, semi-rigid pavement and flexible pavement. The pavements represent the typical pavement types used for the regular road structures. This article is focused on the analysis of the stress state and the displacements of the pavement induced by the moving load from the traffic.

The preliminary application of OSL in comparison with TL for authentication of ancient Chinese bricks

International Nuclear Information System (INIS)

Leung, P.L.; Tang Qiang; Li, Mike; Zhang Chunxiang

2005-01-01

The single-aliquot regenerative-dose (SAR) protocol with optically stimulated luminenscence (OSL) was applied to measure the equivalent dose (ED) of ancient Chinese bricks ranging in age from 180 to 1600 years. In the protocol, sensitivity changes can be corrected by using OSL response to a fixed test dose during measurement. For comparative study between OSL and TL, thermoluminescence (TL) measurement procedures were also applied to determine the paleodose of the bricks. Both results of OSL and TL are in agreement with the known ages of the bricks, and the paleodose ratios(ED OSL / ED TL ) are between 0.96 and 1.21, mean value 1.08+/-0.02. The annual doses of the bricks, estimated by the paleodoses and the known ages, range from 5.07 to 6.79mGy/a, comparable with the measured annual dose values of the bricks. Therefore, it is concluded that the SAR protocol is a rapid and effective OSL technique to authenticate Chinese bricks

Experimental Study on Color Durability of Color Asphalt Pavement

Science.gov (United States)

Ning, Shi; Huan, Su

2017-06-01

Aiming at the poor Color durability and the lack of research on Color asphalt pavement, spraying an anti-tire trace seal resin emulsion on the surface, a Color durable asphalt pavement was proposed. After long-term rolling and long-term aging test, the Color durability was evaluated by RGB function in Photoshop and trace residue rate formula. Test results proved that the Evaluation method was simple and effective. After long-term rolling, the Color of the road surface tends to a constant value. Spraying the emulsion on the road surface can resist tire traces. After long-term aging test, the resistance to tire traces was increased by 26.6% compared with the conventional type, while the former was 44.1% higher than the latter without long-term aging. The Color durable asphalt pavement can effectively improve the ability of Color asphalt pavement to resist tire traces, and significantly improve the Color durability of Color asphalt pavement.

Importance of dowels in transversal joints in concrete pavements

Science.gov (United States)

Grosek, Jiri; Chupik, Vladimir; Stryk, Josef; Brezina, Ilja

2017-09-01

Concrete pavements are designed for heavy loaded road structures. Their usage brings a number of specific issues. It is necessary to solve them all to ensure that concrete pavements will fulfil their function along the whole design period. One of these issues concerns dowels, which are located in transversal joints. Modelling of load, caused by heavy vehicles, with the use of the finite element method, provides valuable information about the stress condition of concrete pavement. The results of modelling can be verified by measurements or experiments in practice. Dowels and tie bars in jointed unreinforced concrete pavements and the importance of their correct placement, dimensions and material quality on pavement behaviour and lifespan were studied as a part of R&D projects of Technology Agency of the Czech Republic Nos. TA02031195 and TE01020168. The paper presents the experience from the modelling and performed experiments and makes conclusions which are important for the use in practice.

Evaluation of the potential for using Greenlandic marine sediments for brick production

DEFF Research Database (Denmark)

Belmonte, Louise Josefine; Bertelsen, Ida Maria Gieysztor

2016-01-01

Fine grained marine sediments from near the Greenlandic towns of Ilulissat, Kangerlussuaq and Sisimiut were assessed as raw materials for local production of building bricks. The assessment included both analysis of the sediment characteristics and physical properties of miniature test brick...

Sustainable Development Factors in Pavement Life-Cycle: Highway/Airport Review

Directory of Open Access Journals (Sweden)

Peyman Babashamsi

2016-03-01

Full Text Available Sustainability has gained as much importance as management in business. Sustainable pavement development as a business practice should involve making evaluations according to the triple bottom line in the pavement life-cycle. Despite the current approaches to evaluating the social as well as economic and environmental feasibility of pavement projects (involving highway and airport infrastructure, there has recently been a lack of consensus on a methodology to guarantee sustainability upon assessment and analysis during the pavement life-cycle. As sustainability is a complex issue, this study intends to further explore sustainability and elaborate on its meaning. The second step involves a general depiction of the major sustainability appraisal tools, namely cost-benefit analysis, life-cycle cost analysis, life-cycle assessment, multi-criteria decision-making, environmental impact assessment and social life-cycle assessment, and an explanation of their cons and pros. Subsequently, the article addresses the application of an organized methodology to highlight the main factors or concepts that should be applied in sustainable pavement development and, more specifically, in sustainable pavement management. In the final step, research recommendations toward sustainability are given. This study is aimed to assist decision-makers in pavement management to plan sustainability frameworks in accordance with probable boundaries and restrictions.

Performance studies of continuously reinforced concrete pavement : pavements without transverse steel.

Science.gov (United States)

1972-01-01

The status of studies of the three continuously reinforced pavement projects near Charlottesville is reported. Of particular interest in these studies are the effects of the elimination of transverse reinforcing steel, the changing characteristics of...

Validation of theoretical models through measured pavement response

DEFF Research Database (Denmark)

Ullidtz, Per

1999-01-01

mechanics was quite different from the measured stress, the peak theoretical value being only half of the measured value.On an instrumented pavement structure in the Danish Road Testing Machine, deflections were measured at the surface of the pavement under FWD loading. Different analytical models were...... then used to derive the elastic parameters of the pavement layeres, that would produce deflections matching the measured deflections. Stresses and strains were then calculated at the position of the gauges and compared to the measured values. It was found that all analytical models would predict the tensile...

Permeable Pavement Research at the Edison Environmental Center

Science.gov (United States)

There are few detailed studies of full-scale, replicated, actively-used permeable pavement systems. Practitioners need additional studies of permeable pavement systems in its intended application (parking lot, roadway, etc.) across a range of climatic events, daily usage conditio...

Preparation and mechanism of the sintered bricks produced from Yellow River silt and red mud

International Nuclear Information System (INIS)

He, Hongtao; Yue, Qinyan; Su, Yuan; Gao, Baoyu; Gao, Yue; Wang, Jingzhou; Yu, Hui

2012-01-01

Highlights: ► The best condition was red mud content of 40% and sintering at 1050 °C for 2 h. ► Bricks’ weight loss was caused by the removal of absorbed water and crystal water. ► Bricks’ sintering shrinkage depended on the sodium and iron compounds of red mud. ► Sintering can strengthen bricks and decrease leaching concentration of toxic metal. - Abstract: The preparation, characteristics and mechanisms of sintered bricks manufactured by Yellow River silt and red mud were studied. The sintering shrinkage, weight loss on ignition, water absorption and compressive strength were tested to determine the optimum preparation condition. Sintering mechanisms were discussed through linear regression analysis. Crystalline components of raw materials and bricks were analyzed by X-ray diffraction. Leaching toxicity of raw materials and bricks were measured according to sulphuric acid and nitric acid method. Radiation safety of the sintered bricks was characterized by calculating internal exposure index and external exposure index. The results showed that at the chosen best parameters (red mud content of 40%, sintering temperature of 1050 °C and sintering time of 2 h), the best characteristics of sintered bricks could be obtained. The weight loss on ignition of sintered bricks was principally caused by the removal of absorbed water and crystal water. The sintering shrinkage of sintered bricks mainly depended on sodium compounds and iron compounds of red mud. The sintering process made some components of raw materials transform into other crystals having better thermostability. Besides, the leaching toxicity and radioactivity index of sintered bricks produced under the optimum condition were all below standards.

Geo synthetic-reinforced Pavement systems; Sistemas de pavimentos reforzados con geosinteticos

Energy Technology Data Exchange (ETDEWEB)

Zornberg, J. G.

2014-02-01

Geo synthetics have been used as reinforcement inclusions to improve pavement performance. while there are clear field evidence of the benefit of using geo synthetic reinforcements, the specific conditions or mechanisms that govern the reinforcement of pavements are, at best, unclear and have remained largely unmeasured. Significant research has been recently conducted with the objectives of: (i) determining the relevant properties of geo synthetics that contribute to the enhanced performance of pavement systems, (ii) developing appropriate analytical, laboratory and field methods capable of quantifying the pavement performance, and (iii) enabling the prediction of pavement performance as a function of the properties of the various types of geo synthetics. (Author)

Clay bricks prepared with sugarcane bagasse and rice husk ash – A sustainable solution

Directory of Open Access Journals (Sweden)

Azhar Saleem Muhammad

2017-01-01

Full Text Available This study aims to characterize the clay bricks produced by the addition of the two agricultural waste materials i.e. sugarcane bagasse and rice husk ash. Disposing off these waste materials is a very challenging task and is a hazard to environment. The sugarcane bagasse and rice husk ash were collected locally from the cities of Peshawar and Wazirabad, respectively. These were mixed with the clay for brick manufacturing in three different proportions i.e. 5, 10 and 15% by weight of clay. Mechanical i.e. compressive strength and modulus of rupture and durability properties i.e. water absorption; freeze-thaw and sulphate resistance of these bricks were evaluated. Test results indicated that the sulphate attack resistance and efflorescence of clay bricks incorporating sugarcane bagasse and rice husk ash have been increased significantly. However, no significant effect on mechanical properties was observed. Furthermore, the additions of wastes have reduced the unit weight of bricks which decrease the overall weight of the structure leading to economical construction. Therefore, it can be concluded that the addition of waste materials in brick manufacturing can minimize the environmental burden leading towards more economical and sustainable construction.

Analysis of natural stone block pavements in urban shared areas

Directory of Open Access Journals (Sweden)

Pablo Zoccali

2018-06-01

Full Text Available This paper analysed and verified an existing block stone pavement in an urban shared area. Fatigue and rutting verification was performed respectively for bound and unbound pavement materials using analytical curves available in the literature. The commercial finite element (FE software Abaqus® was used to calculate the response of the pavement when subjected to different loading, construction and geometrical configurations (i.e. type of analysis, shape and size of meshes, boundary conditions, and bonding contacts between the pavements layers. At the end of this study, a static model of a structure with hexahedral blocks having sides of 0.02 m, with full bonded layers and restrained horizontal displacements on the model sides, was implemented to evaluate the maximum tensile stress induced in a block when the load is applied at its centre. This analysis highlighted the need for rigorous criteria for a correct design, in order to avoid inappropriate and expensive use of road materials. Keywords: Block pavement, Commercial vehicle loads, Finite element model, Hexagonal Stone block, Pedestrian pavement, Shared area

Micromechanical models to guide the development of synthetic 'brick and mortar' composites

NARCIS (Netherlands)

Begley, M.R.; Philips, N.R.; Compton, B.G.; Wilbrink, D.V.; Ritchie, R.O.; Utz, M.

2012-01-01

This paper describes a micromechanical analysis of the uniaxial response of composites comprising elastic platelets (bricks) bonded together with thin elastic perfectly plastic layers (mortar). The model yields closed-form results for the spatial variation of displacements in the bricks as a

Long-term Metal Performance of Three Permeable Pavements

Science.gov (United States)

EPA constructed a 4,000-m2 parking lot surfaced with three permeable pavements (permeable interlocking concrete pavers, pervious concrete, and porous asphalt) on the Edison Environmental Center in Edison, NJ in 2009. Samples from each permeable pavement infiltrate were collected...

Pressure relief experiments on a cyclindrical carbon brick tube

International Nuclear Information System (INIS)

Lang, H.; Weise, H.J.; Ennen, P.

1978-08-01

Pressure relief experiments have been carried out on a carbon brick tube. The outer diameter of the specimen was 580 mm, the inner diameter 280 mm, the length 800 mm. The experiments were made with helium at the temperature of the environment. The measurements were carried out in the pressure range from 15 upto 39 bar. The pressure loss was measured dependent on the initial pressure and on time at 5 positions uniformly distributed over the thickness of the tube wall and in the pressure vessel. The maximum pressure transients occurred amounted to approximately 60 bar/second. The maximum overpressure with respect to the environment which occurred in the carbon brick during the relief experiments was about 3.3 bar. The measurements distinctly showed the presence and the effects of inhomogeneities in the sample material. No damages or changes in the carbon brick, which could be regarded as a consequence of the experiments, were found. (orig./GSC) [de

Wave Manipulation in Metamaterials: A LEGO® Bricks Enabled Platform

Science.gov (United States)

Celli, Paolo; Gonella, Stefano

In this work, we show how simple, reconfigurable arrangements of LEGO® bricks can be turned into the building blocks of an experimental platform for the investigation of wave phenomena in metamaterial architectures. The approach involves the assembly of reconfigurable specimens consisting of patterns of bricks on a baseplate and the use of a 3D laser vibrometer to reconstruct global and local wave features. The ability to seamlessly transition between different topologies makes this an effective approach for rapid experimental verification and proof of concept in the arena of mechanical metamaterials engineering. The intuitive nature of the brick-and-baseplate assembly paradigm can also be leveraged to implement families of intuitive lab demonstrations with significant didactic and scientific outreach potential. The versatility of the platform is tested through a series of experiments that illustrate a variety of wave manipulation effects, such as waveguiding and seismic isolation, both in periodic and disordered topologies. We acknowledge the support of the National Science Foundation (Grant CMMI-1266089).

Low Temperature Regolith Bricks for In-Situ Structural Material

Science.gov (United States)

Grossman, Kevin; Sakthivel, Tamil S.; Mantovani, James; Seal, Sudipta

2016-01-01

Current technology for producing in-situ structural materials on future missions to Mars or the moon relies heavily on energy-intensive sintering processes to produce solid bricks from regolith. This process requires heating the material up to temperatures in excess of 1000 C and results in solid regolith pieces with compressive strengths in the range of 14000 to 28000 psi, but are heavily dependent on the porosity of the final material and are brittle. This method is currently preferred over a low temperature cementation process to prevent consumption of precious water and other non-renewable materials. A high strength structural material with low energy requirements is still needed for future colonization of other planets. To fulfill these requirements, a nano-functionalization process has been developed to produce structural bricks from regolith simulant and shows promising mechanical strength results. Functionalization of granular silicate particles into alkoxides using a simple low temperature chemical process produces a high surface area zeolite particles that are held together via inter-particle oxygen bonding. Addition of water in the resulting zeolite particles produces a sol-gel reaction called "inorganic polymerization" which gives a strong solid material after a curing process at 60 C. The aqueous solution by-product of the reaction is currently being investigated for its reusability; an essential component of any ISRU technology. For this study, two batches of regolith bricks are synthesized from JSC-1A; the first batch from fresh solvents and chemicals, the second batch made from the water solution by-product of the first batch. This is done to determine the feasibility of recycling necessary components of the synthesis process, mainly water. Characterization including BET surface area, SEM, and EDS has been done on the regolith bricks as well as the constituent particles,. The specific surface area of 17.53 sq m/g (average) of the granular regolith

Cracking of open traffic rigid pavement

Directory of Open Access Journals (Sweden)

Niken Chatarina

2017-01-01

Full Text Available The research is done by observing the growth of real structure cracking in Natar, Lampung, Indonesia compared to C. Niken’s et al research and literature study. The rigid pavement was done with open traffic system. There are two main crack types on Natar rigid pavement: cracks cross the road, and cracks spreads on rigid pavement surface. The observation of cracks was analyzed by analyzing material, casting, curing, loading and shrinkage mechanism. The relationship between these analysis and shrinkage mechanism was studied in concrete micro structure. Open traffic make hydration process occur under vibration; therefore, fresh concrete was compressed and tensioned alternately since beginning. High temperature together with compression, cement dissociation, the growth of Ca2+ at very early age leads abnormal swelling. No prevention from outside water movement leads hydration process occur with limited water which caused spreads fine cracks. Limited water improves shrinkage and plastic phase becomes shorter; therefore, rigid pavement can’t accommodate the abnormal swelling and shrinking alternately and creates the spread of cracks. Discontinuing casting the concrete makes both mix under different condition, the first is shrink and the second is swell and creates weak line on the border; so, the cracks appear as cracks across the road.

Photocatalytic pavement blocks. Air purification by pavement blocks. Final results of the research at BRRC

Energy Technology Data Exchange (ETDEWEB)

NONE

2009-07-01

The use of materials can influence to a large extent the environmental impact of traffic and of road infrastructure. Especially in urban areas, where the risk on smog formation during hot summer days is high, the use of photocatalytic pavement blocks can reduce the air pollution significantly. A project on environmental friendly concrete pavement blocks is conducted at the Belgian Road Research Centre. The use of photocatalytic material in the surface of pavement blocks to obtain air purifying materials is investigated. In contact with light, TiO2 as photocatalyst, is able to reduce the NO and NO2 content in the air, caused by the exhaust of traffic. The efficiency is tested on pavement blocks, but the technique can as well be applied on other road elements (e.g. noise reducing walls, linear elements) or as a coating on new materials or existing structures. At the previous TRA conference in Gotenborgh, Sweden, the principle of photocatalysis was presented. In this paper, emphasis will be put on the final results of the 4-year project obtained in laboratory as well as on site at the Leien of Antwerp (10,000 m{sup 2}). The results indicate a durable efficiency towards NOx reduction, which is in favour for the diminishing of the risk on ozone formation. However, the precise translation from the laboratory towards the site is still in question. The results obtained during the project are discussed in this paper.

Photocatalytic pavement blocks. Air purification by pavement blocks. Final results of the research at BRRC

International Nuclear Information System (INIS)

2009-01-01

The use of materials can influence to a large extent the environmental impact of traffic and of road infrastructure. Especially in urban areas, where the risk on smog formation during hot summer days is high, the use of photocatalytic pavement blocks can reduce the air pollution significantly. A project on environmental friendly concrete pavement blocks is conducted at the Belgian Road Research Centre. The use of photocatalytic material in the surface of pavement blocks to obtain air purifying materials is investigated. In contact with light, TiO2 as photocatalyst, is able to reduce the NO and NO2 content in the air, caused by the exhaust of traffic. The efficiency is tested on pavement blocks, but the technique can as well be applied on other road elements (e.g. noise reducing walls, linear elements) or as a coating on new materials or existing structures. At the previous TRA conference in Gotenborgh, Sweden, the principle of photocatalysis was presented. In this paper, emphasis will be put on the final results of the 4-year project obtained in laboratory as well as on site at the Leien of Antwerp (10,000 m 2 ). The results indicate a durable efficiency towards NOx reduction, which is in favour for the diminishing of the risk on ozone formation. However, the precise translation from the laboratory towards the site is still in question. The results obtained during the project are discussed in this paper

An assessment of the skid resistance effect on traffic safety under wet-pavement conditions.

Science.gov (United States)

Pardillo Mayora, José M; Jurado Piña, Rafael

2009-07-01

Pavement-tire friction provides the grip that is required for maintaining vehicle control and for stopping in emergency situations. Statistically significant negative correlations of skid resistance values and wet-pavement accident rates have been found in previous research. Skid resistance measured with SCRIM and crash data from over 1750km of two-lane rural roads in the Spanish National Road System were analyzed to determine the influence of pavement conditions on safety and to assess the effects of improving pavement friction on safety. Both wet- and dry-pavement crash rates presented a decreasing trend as skid resistance values increased. Thresholds in SCRIM coefficient values associated with significant decreases in wet-pavement crash rates were determined. Pavement friction improvement schemes were found to yield significant reductions in wet-pavement crash rates averaging 68%. The results confirm the importance of maintaining adequate levels of pavement friction to safeguard traffic safety as well as the potential of pavement friction improvement schemes to achieve significant crash reductions.

Wood fuel use in Tanzania rural-based industries. Brick kiln studies in Tanzania

Energy Technology Data Exchange (ETDEWEB)

Kiwele, P.M.; Mbise, H.A.; Mwihava, N.C.X.; Svenningsson, P.J.

1999-07-01

About 90% of the annual total energy consumed in Tanzania is biomass-based, mainly in the form of wood fuel. Small-scale brick-making is one of the major consumers of wood fuel, with Arusha, Iringa and Mbeya being the main areas where brick-making activities take place. In 1993, the Stockholm Environment Institute (SEI) in collaboration with the Ministry of Energy and Minerals (MEM) proposed a project to undertake studies on fuelwood in small rural industries of Tanzania, particularly brick-making. The study on wood fuel utilisation involved field measurements and analyses with the aim of establishing major sources of energy losses and to recommend measures regarding fuel switching, kiln thermal efficiency improvements, and the yield and quality of bricks. The positive feedback would mean reduced demand for fuelwood and hence reduced deforestation rate and therefore environmental protection. The implementation of the project, which commenced in 1994, involved field measurements in order to establish kiln performances as well as laboratory tests to determine the qualities of the fired bricks. At a later stage of implementation, efforts were made to consider other potential fuels (sawdust and coal) for firing the kilns. The main indicators of kiln performance include thermal efficiency, specific energy consumption (SEC), which is sometimes referred to as specific fuel consumption (SFC; yield; and quality. The average SEC for Mbeya region was found to vary from 1.11 to 1.54 while for Iringa region the range was from 1.21 to 1.84 MJ/kg fired brick. The data for Arusha was in the range of 0.76 to 3.3 MJ/kg of fired brick. The low SEC may not necessarily give a reasonable indication of the kiln performance because kiln operators in Mbeya mould larger size bricks which are unloaded from incomplete firing conditions. The fired bricks at Babati (Arusha), though of work-size, are of low quality and consume very little wood fuel. Findings obtained under the SADC project four

Effects of moving dynamic tyre loads on tyre-pavement contact stresses

CSIR Research Space (South Africa)

Steyn, WJvdM

2002-01-01

Full Text Available The purpose of this paper is to indicate the effect that moving dynamic tyre loads has on the tyre-pavement contact stresses used in pavement analysis. Traditionally tyre loads (in pavement analysis) are modelled as constant loads applied through...

Toward using tire-road contact stresses in pavement design and analysis

CSIR Research Space (South Africa)

De Beer, Morris

2012-10-01

Full Text Available pavement design. Four different tire models were used to represent a single tire type in order to demonstrate its effect on road pavement response of a typical South African pavement structure. Only applied vertical stress was used for the analyses...

Teaching Methodology of Flexible Pavement Materials and Pavement Systems

Science.gov (United States)

Mehta, Yusuf; Najafi, Fazil

2004-01-01

Flexible pavement materials exhibit complex mechanical behavior, in the sense, that they not only show stress and temperature dependency but also are sensitive to moisture conditions. This complex behavior presents a great challenge to the faculty in bringing across the level of complexity and providing the concepts needed to understand them. The…

Pavement edge treatment.

Science.gov (United States)

2013-01-01

Four projects were built over two construction seasons using special devices attached to the paving machine that produces a 30 slope on the outside pavement edge instead of the near vertical drop-off common with conventional paving equipment. This ...

Tests used in Project Level Flexible Pavement rehabilitation studies. Research report

Energy Technology Data Exchange (ETDEWEB)

Jordaan, G.J.

1986-09-01

This paper gives guidelines for the use of tests and their interpretation in the various phases of flexible pavement rehabilitation design as currently adopted in South Africa. The procedure advocated involves a systematic approach to the investigation, evaluation and analysis of the existing pavement. In the recommended procedure, use is made of past pavement behavior and pavement condition, thereby making possible an early assessment of additional information needed. Much emphasis is placed on the optimum utilization of available resources in designing the best applicable remedy to an existing problem. The paper gives a comprehensive list of criteria for parameters measured on a routine basis on South African roads. The procedure suggested allows the condition of pavements to be expressed in comparable terms. Information on the development and use of some new and specialized tests which are used in pavement rehabilitation is given in an appendix.

3D Tyre/Road pavement contact stress measurements

CSIR Research Space (South Africa)

De Beer, Morris

2010-10-01

Full Text Available The CSIR’s proprietary Stress-in-Motion (SIM) measurements provide rational descriptions of 1D, 2D and 3D tyre/road pavement stresses for: Road pavement design testing and evaluation, as well as tyre design, testing and evaluation....

The Simulation Realization of Pavement Roughness in the Time Domain

Science.gov (United States)

XU, H. L.; He, L.; An, D.

2017-10-01

As the needs for the dynamic study on the vehicle-pavement system and the simulated vibration table test, how to simulate the pavement roughness actually is important guarantee for whether calculation and test can reflect the actual situation or not. Using the power spectral density function, the simulation of pavement roughness can be realized by Fourier inverse transform. The main idea of this method was that the spectrum amplitude and random phase were obtained separately according to the power spectrum, and then the simulation of pavement roughness was obtained in the time domain through the Fourier inverse transform (IFFT). In the process, the sampling interval (Δl) was 0.1m, and the sampling points(N) was 4096, which satisfied the accuracy requirements. Using this method, the simulate results of pavement roughness (A~H grades) were obtain in the time domain.

Review of modern methods for continuous friction measurement on airfield pavements

Science.gov (United States)

Iwanowski, Paweł; Blacha, Krzysztof; Wesołowski, Mariusz

2018-05-01

The safety of traffic, including both road and air traffic on a ground manoeuvre area, depends on many factors. These mainly include the anti-slip properties of a road or airfield pavement on which the traffic takes place. The basic pavement parameter that determines its characteristics in terms of anti-slip properties is the skid resistance, which constitutes the ratio of the wheel downforce and the friction on the contact surface. There are currently many devices for continuous measurement of the skid resistance (Continuous Friction-Measuring Equipment - CFME) around the world. Most of them, in principle, do not vary much from one another. Most of the devices measure the measuring wheel’s downforce on the pavement and the friction on the wheel-pavement contact surface. The skid resistance is the result of this measurement. The devices vary in many aspects, such as the type and size of the used measuring tyre, pavement-wheel slip or tyre pressure. This does not mean that the results obtained from various devices mbe directly compared. On the other hand, each device allows determining the pavement’s anti-slip conditions in terms of the requirements specified for the given type of devices, thereby enabling pavement classification in these terms. The classification allows for comparing the results obtained from various measuring devices. The paper presents an overview of equipment used in Poland and around the world to measure the skid resistance on airfield pavements. The authors draw attention to the requirements for pavements in terms of their roughness, with division into road and airfield pavements.

Leaching and geochemical behavior of fired bricks containing coal wastes.

Science.gov (United States)

Taha, Yassine; Benzaazoua, Mostafa; Edahbi, Mohamed; Mansori, Mohammed; Hakkou, Rachid

2018-03-01

High amounts of mine wastes are continuously produced by the mining industry all over the world. Recycling possibility of some wastes in fired brick making has been investigated and showed promising results. However, little attention is given to the leaching behavior of mine wastes based fired bricks. The objective of this paper is to evaluate the geochemical behavior of fired bricks containing different types of coal wastes. The leachates were analyzed for their concentration of As, Ba, Cd, Co, Cr, Cu, Mo, Ni, Pb, Zn and sulfates using different leaching tests; namely Tank Leaching tests (NEN 7375), Toxicity Characteristic Leaching Procedure (TCLP) and pH dependence test (EPA, 1313). The results showed that the release of constituents of potential interest was highly reduced after thermal treatment and were immobilized within the glassy matrix of the fired bricks. Moreover, it was also highlighted that the final pH of all fired samples changed and stabilized around 8-8.5 when the initial pH of leaching solution was in the range 2.5-11.5. The release of heavy metals and metalloids (As) tended to decrease with the increase of pH from acidic to alkaline solutions while Mo displayed a different trend. Copyright © 2017 Elsevier Ltd. All rights reserved.

Crushing damage estimation for pavement with lightly cementitious bases

CSIR Research Space (South Africa)

De Beer, Morris

2014-07-01

Full Text Available . Department of Transport. Pretoria, South Africa. Litwinowicz and De Beer., 2013. Long term crushing performance of lightly cementitious pavement materials – update to the South African procedures. Road Materials and Pavement Design. Maina, J.W., De... Beer, M. and van Rensburg, Y., 2013. Modelling Tyre-Road Contact Stresses in Pavement Design and Analysis. Proceedings of 32nd Southern Africa transport conference, Pretoria, July 2013. pp 336-345: SAPDM, (2014). http://www.sapdm.co.za/, last...

Reliability of using nondestructive tests to estimate compressive strength of building stones and bricks

Directory of Open Access Journals (Sweden)

Ali Abd Elhakam Aliabdo

2012-09-01

Full Text Available This study aims to investigate the relationships between Schmidt hardness rebound number (RN and ultrasonic pulse velocity (UPV versus compressive strength (fc of stones and bricks. Four types of rocks (marble, pink lime stone, white lime stone and basalt and two types of burned bricks and lime-sand bricks were studied. Linear and non-linear models were proposed. High correlations were found between RN and UPV versus compressive strength. Validation of proposed models was assessed using other specimens for each material. Linear models for each material showed good correlations than non-linear models. General model between RN and compressive strength of tested stones and bricks showed a high correlation with regression coefficient R2 value of 0.94. Estimation of compressive strength for the studied stones and bricks using their rebound number and ultrasonic pulse velocity in a combined method was generally more reliable than using rebound number or ultrasonic pulse velocity only.

Clay-brick firing in a high-temperature solar furnace

Energy Technology Data Exchange (ETDEWEB)

Villeda-Munoz, G. [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Instituto Politecnico Nacional, Unidad Queretaro, Queretaro (Mexico)]. E-mail: gvilledam@ipn.mx; Castaneda-Miranda, A. [Computation & amp; Mechatronic Studies Division, Universidad Politecnica de Queretaro, Queretaro (Mexico)]. E-mail: acastaneda@upq.edu.mx; Pless, R.C. [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Instituto Politecnico Nacional, Unidad Queretaro, Queretaro (Mexico)]. E-mail: rpless@ipn.mx; Vega-Duran, J.T. [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Instituto Politecnico Nacional, Unidad Queretaro, Queretaro (Mexico); Pineda-Pinon, J. [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Instituto Politecnico Nacional, Unidad Queretaro, Queretaro (Mexico)]. E-mail: jpinedap@ipn.mx

2011-10-15

The firing process for clay-brick production in traditional kilns generates atmospheric pollution when industrial and domestic scrap is used as fuel. An alternative is presented here, using the solar energy for clay-brick firing. We are developing a system for clay-brick firing to reach temperatures between 900 degrees Celsius and 1050 degrees Celsius; these temperatures are sufficiently high to fire bricks or similar ceramic products. The present paper describes the design and characterization of the components of a solar furnace for clay-brick firing with inner chamber dimensions of 0.48 * 0.61 * 0.64 m. To convey the sunlight to the firing chamber, a heliostat with nine 1 * 1 m mirrors is used to send the rays of the sun to an off-axis parabolic concentrator that focuses the light on the entrance of the firing chamber. The heliostat has a solar-tracking system which makes primary and secondary adjustments to assure that the reflected solar radiation always arrives at the concentrator. The firing chamber contains a prismatic cavity that absorbs the solar radiation to generate the heat which is needed for baking the bricks inside the firing chamber. [Spanish] El proceso de coccion para la produccion de tabiques de arcilla en hornos tradicionales genera contaminacion atmosferica cuando los desechos industriales y domesticos se usan como combustibles. Aqui se presenta una alternativa, utilizando la energia solar para la coccion de tabiques de arcilla. Estamos desarrollando un sistema para la coccion de tabiques de arcilla para alcanzar temperaturas entre 900 grados centigradosy 1050 grados centigrados; estas temperaturas son suficientemente altas para cocer tabiques o productos ceramicos similares. El presente articulo describe el diseno y caracterizacion de los componentes de un horno solar para la coccion de tabiques de arcilla con una camara con dimensiones internas de 0.48 * 0.61 *× 0.64 m. Para dirigir los rayos solares a la camara de coccion, un heliostato

Study on the Vehicle Dynamic Load Considering the Vehicle-Pavement Coupled Effect

Science.gov (United States)

Xu, H. L.; He, L.; An, D.

2017-11-01

The vibration of vehicle-pavement interaction system is sophisticated random vibration process and the vehicle-pavement coupled effect was not considered in the previous study. A new linear elastic model of the vehicle-pavement coupled system was established in the paper. The new model was verified with field measurement which could reflect the real vibration between vehicle and pavement. Using the new model, the study on the vehicle dynamic load considering the vehicle-pavement coupled effect showed that random forces (centralization) between vehicle and pavement were influenced largely by vehicle-pavement coupled effect. Numerical calculation indicated that the maximum of random forces in coupled model was 2.4 times than that in uncoupled model. Inquiring the reason, it was found that the main vibration frequency of the vehicle non-suspension system was similar with that of the vehicle suspension system in the coupled model and the resonance vibration lead to vehicle dynamic load increase significantly.

Use of bottom ash from olive pomace combustion in the production of eco-friendly fired clay bricks.

Science.gov (United States)

Eliche-Quesada, D; Leite-Costa, J

2016-02-01

Olive pomace bottom ash was used to replace different amounts (10-50wt%) of clay in brick manufacturing. The aim of this study is both studying bricks properties and showing a new way of olive pomace bottom ash recycling. Properties of waste bricks were compared to conventional products following standard procedures in order to determine the maximum waste percentage. The amount of olive pomace bottom ash is limited to 20wt%, obtaining bricks with superior engineering properties when 10wt% of waste is added. Adding higher amount of waste (30-50wt%) resulted in bricks with water absorption and compressive strength values on the edge of meeting those established by standards. Therefore, the addition of 10 and 20wt% of olive pomace bottom ash produced bricks with a bulk density of 1635 and 1527kg/m(3) and a compressive strength of 33.9MPa and 14.2MPa, respectively. Fired bricks fulfil standards requirements for clay masonry units, offering, at the same time, better thermal insulation of buildings due to a reduction in thermal conductivity of 14.4% and 16.8% respectively, compared to control bricks (only clay). Copyright © 2015 Elsevier Ltd. All rights reserved.

Nutrient Infiltrate Concentrations from Three Permeable Pavement Types

Science.gov (United States)

While permeable pavement is increasingly being used to control stormwater runoff, field-based, side-by-side investigations on the effects different pavement types have on nutrient concentrations present in stormwater runoff are limited. In 2009, the U.S. EPA constructed a 0.4-ha...

Heat and damp transport in cavity bricks. Waerme- und Feuchtetransport in Hochlochziegeln

Energy Technology Data Exchange (ETDEWEB)

Elsner, M

1987-11-19

The aim of this work is a systematic measurement of the structural effect of cavity bricks on the thermal insulation and thermal storage values depending on the material values of the bricks and the mortar. The arrangement and orientation of the hollow spaces and their dimensions should be varied. Brick shapes with socalled handle slots, which give more convenient handling, and with mortar pockets instead of mortar gaps, should be taken into account in the investigation. Special attention should be paid to the heat transport mechanism in the hollow spaces, where thermal conduction, thermal radiation and convection heat transport are superimposed on one another. The second main aim of the work is the calculation of the coupled heat and damp transport in hollow bricks. The heat and damp transport is described by a coupled system of differential equations, where the decisive transport coefficients should be shown as a function of the variables determining the transport processes. (orig./MM).

Case study of fly ash brick manufacturing units at Kota in Rajasthan

Science.gov (United States)

Sharma, Y.; Saxena, B. K.; Rao, K. V. S.

2018-03-01

Kota Super Thermal Power Station of 1240 MW is located at Kota in Rajasthan, India. The quantity of fly ash generated by it is about 1.64 to 2.03 million tonnes per year. This fly ash is being utilized for making bricks, tiles, portland pozzolana cement, construction of highways, and other purposes. 1.79 million tonnes of fly ash was utilized for different applications in one year duration from April 01st, 2015 to March 31st, 2016. Out of this total utilization, 0.6439 million tonnes (36.06 %) of fly ash was used for making bricks, blocks, and tiles. In this paper, a case study of two fly ash brick manufacturing units using fly ash produced from Kota Super Thermal Power Station is described. These units produce about 15,000 and 20,000 bricks respectively by employing 10 and 16 workers each and are making a profit of about Rs. 6,000 and Rs. 8,000 per day in one shift.

A User Friendly Software for Rigid Pavement Design

Directory of Open Access Journals (Sweden)

Aydın Kıcı

2017-12-01

Full Text Available Concrete pavements as concrete road slab, appear as a strong alternative for flexible superstructures especially because of their low cost for maintenance and repair and the high performance they show under heavy axle loads. The design of these concrete road slabs is quite different from the traditional concrete and reinforced concrete structures’ design. In the design for this kind of pavements, traffic conditions should be defined properly and considered an addition to the concrete and platform properties. There have been designing methods developed based on both experimental and mechanic foundations for concrete pavements. The most important ones of these methods are AASHTO (1993 and PCA (1984. In both design methods, it’s significant to know the maximum deflections and maximum strains the vehicles’ loads cause on the pavement. The calculation of this maximum deflections and maximum strains can be done via the finite element method or the closed formulas which have been developed by Westergaard. In this study, a user-friendly software has been developed based on AASHTO 1993, PCA 1984 design methods and Westergaard formulas. Thanks to this software, the user who wants to design the concrete pavement as concrete road slab can obtain the essential parameters automatically by entering the required data for the design.

75 FR 4528 - Certain Magnesia Carbon Bricks From the People's Republic of China: Alignment of Final...

Science.gov (United States)

2010-01-28

... the PRC and Mexico. See Certain Magnesia Carbon Bricks from the People's Republic of China: Initiation... Bricks from the People's Republic of China and Mexico: Initiation of Antidumping Duty Investigations, 74... Bricks From the People's Republic of China: Alignment of Final Countervailing Duty Determination With...

Assessment of occupational health problems and physiological stress among the brick field workers of West Bengal, India

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Banibrata Das

2014-08-01

Full Text Available Objectives: The brick field industry is one of the oldest industries in India, which employs a large number of workers of poor socioeconomic status. The main aim of the present investigation is i to determine the prevalence of musculoskeletal disorders among brick field workers, ii to determine the prevalence of respiratory disorders and physiological stress among brick field workers compared to control workers. Material and Methods: For this study, a total of 220 brick field workers and 130 control subjects were selected randomly. The control subjects were mainly involved in hand-intensive jobs. The Modified Nordic Questionnaire was applied to assess the discomfort felt among both groups of workers. Thermal stress was also assessed by measuring the WBGT index. The pulmonary functions were checked using the spirometry. Physiological assessment of the workload was carried out by recording the heart rate and blood pressure of the workers prior to work and just after work in the field. Results: Brick field workers suffered from pain especially in the lower back (98%, hands (93%, knees (86%, wrists (85%, shoulders (76% and neck (65%. Among the brick-making activities, brick field workers felt discomfort during spading for mud collection (98%, carrying bricks (95% and molding (87%. The results showed a significantly lower p value < 0.001 in FVC, FEV1, FEV1/FVC ratio and PEFR in brick field workers compared to the control group. The post-activity heart rate of the brick field workers was 148.6 beats/min, whereas the systolic and diastolic blood pressure results were 152.8 and 78.5 mm/Hg, respectively. Conclusions: This study concludes that health of the brick field workers was highly affected due to working in unhealthy working conditions for a long period of time.

The effect of sludge water treatment plant residuals on the properties of compressed brick

Science.gov (United States)

Shamsudin, Shamrul-Mar; Shahidan, S.; Azmi, M. A. M.; Ghaffar, S. A.; Ghani, M. B. Abdul; Saiful Bahari, N. A. A.; Zuki, S. S. M.

2017-11-01

The focus of this study is on the production of compressed bricks which contains sludge water treatment plant (SWTP) residuals obtained from SAJ. The main objective of this study is to utilise and incorporate discarded material (SWTP) in the form of residual solution to produce compressed bricks. This serves as one of the recycling efforts to conserve the environment. This study determined the optimum mix based on a mix ratio of 1:2:4 (cement: sand: soil) in the production of compressed bricks where 5 different mixes were investigated i. e. 0%, 5%, 10%, 20%, and 30% of water treatment plant residue solution. The production of the compressed bricks is in accordance with the Malaysian Standard MS 7.6: 1972 and British Standard BS 3921: 1985 - Compressive Strength & Water Absorption. After being moulded and air dried, the cured bricks were subjected to compression tests and water absorption tests. Based on the tests conducted, it was found that 20% of water treatment plant residue solution which is equivalent to 50% of soil content replacement with a mix composition of [10: cement] [20: sand] [20: soil] [20: water treatment plant residue solution] is the optimum mix. It was also observed that the bricks containing SWTP residuals were lighter in weight compared to the control specimens

Impact of the variation in dynamic vehicle load on flexible pavement responses

Science.gov (United States)

Ahsanuzzaman, Md

The purpose of this research was to evaluate the dynamic variation in asphalt pavement critical responses due to dynamic tire load variations. An attempt was also made to develop generalized regression equations to predict the dynamic response variation in flexible pavement under various dynamic load conditions. The study used an extensive database of computed pavement response histories for five different types of sites (smooth, rough, medium rough, very rough and severely rough), two different asphalt pavement structures (thin and thick) at two temperatures (70 °F and 104 °F), subjected to a tandem axle dual tire at three speeds 25, 37 and 50 mph (40, 60 and 80 km/h). All pavement responses were determined using the 3D-Move Analysis program (Version 1.2) developed by University of Nevada, Reno. A new term called Dynamic Response Coefficient (DRC) was introduced in this study to address the variation in critical pavement responses due to dynamic loads as traditionally measured by the Dynamic Load Coefficient (DLC). While DLC represents the additional varying component of the tire load, DRC represents the additional varying component of the response value (standard deviation divided by mean response). In this study, DRC was compared with DLC for five different sites based on the roughness condition of the sites. Previous studies showed that DLC varies with vehicle speed and suspension types, and assumes a constant value for the whole pavement structure (lateral and vertical directions). On the other hand, in this study, DRC was found to be significantly varied with the asphalt pavement and function of pavement structure, road roughness conditions, temperatures, vehicle speeds, suspension types, and locations of the point of interest in the pavement. A major contribution of the study is that the variation of pavement responses due to dynamic load in a flexible pavement system can be predicted with generalized regression equations. Fitting parameters (R2) in the

Design of semi-rigid type of flexible pavements

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Pranshoo Solanki

2017-03-01

Full Text Available The primary objective of the study presented in this paper is to develop design curves for performance prediction of stabilized layers and to compare semi-rigid flexible pavement designs between the empirical AASHTO 1993 and the mechanistic-empirical pavement design methodologies. Specifically, comparisons were made for a range of different sections consisting of cementitious layers stabilized with different types and percentages of additives. It is found that the design thickness is influenced by the type of soil, additive, selection of material property and design method. Cost comparisons of sections stabilized with different percentage and type of additives showed that CKD-stabilization provides economically low cost sections as compared to lime- and CFA-stabilized sections. Knowledge gained from the parametric analysis of different sections using AASHTO 1993 and MEPDG is expected to be useful to pavement designers and others in implementation of the new MEPDG for future pavement design. Keywords: Semi-rigid, Mechanistic, Resilient modulus, Fatigue life, Reliability, Traffic

Impacts of pavement types on in-vehicle noise and human health.

Science.gov (United States)

Li, Qing; Qiao, Fengxiang; Yu, Lei

2016-01-01

Noise is a major source of pollution that can affect the human physiology and living environment. According to the World Health Organization (WHO), an exposure for longer than 24 hours to noise levels above 70 dB(A) may damage human hearing sensitivity, induce adverse health effects, and cause anxiety to residents nearby roadways. Pavement type with different roughness is one of the associated sources that may contribute to in-vehicle noise. Most previous studies have focused on the impact of pavement type on the surrounding acoustic environment of roadways, and given little attention to in-vehicle noise levels. This paper explores the impacts of different pavement types on in-vehicle noise levels and the associated adverse health effects. An old concrete pavement and a pavement with a thin asphalt overlay were chosen as the test beds. The in-vehicle noise caused by the asphalt and concrete pavements were measured, as well as the drivers' corresponding heart rates and reported riding comfort. Results show that the overall in-vehicle sound levels are higher than 70 dB(A) even at midnight. The newly overlaid asphalt pavement reduced in-vehicle noise at a driving speed of 96.5 km/hr by approximately 6 dB(A). Further, on the concrete pavement with higher roughness, driver heart rates were significantly higher than on the asphalt pavement. Drivers reported feeling more comfortable when driving on asphalt than on concrete pavement. Further tests on more drivers with different demographic characteristics, along highways with complicated configurations, and an examination of more factors contributing to in-vehicle noise are recommended, in addition to measuring additional physical symptoms of both drivers and passengers. While there have been many previous noise-related studies, few have addressed in-vehicle noise. Most studies have focused on the noise that residents have complained about, such as neighborhood traffic noise. As yet, there have been no complaints by

Determination of coefficient of thermal expansion effects on Louisiana's PCC pavement design.

Science.gov (United States)

2011-12-01

With the development of the Mechanistic Empirical Pavement Design Guide (MEPDG) as a new pavement design tool, the : coefficient of thermal expansion (CTE) is now considered a more important design parameter in estimating pavement : performance inclu...

Magnetic inclination from Brazilian bricks and application to Archeomagnetic dating

Science.gov (United States)

Begnini, G. S.; Hartmann, G. A.; Trindade, R. I.

2013-05-01

The Earth's magnetic field (EMF) is recorded in archeological baked materials carrying a stable remanent magnetization. This magnetic record can be used for indirectly date the archeological material by comparison with "reference curves" of the EMF. In this work we present magnetic inclination data from two different sites in southeastern Brazil, an ancient and a modern one: (a) a sampling at the ancient sugarcane mill Engenho Central de Piracicaba (ECP, 1881-1974 AD), and (b) a controlled survey at the modern brickyard Olaria Schiavolin (OS). Both of them are located in the city of Piracicaba, São Paulo State, Brazil. Magnetic measurements included stepwise thermal and alternating field demagnetization, anisotropy of magnetic susceptibility (AMS) and low-field magnetic susceptibility vs. temperature. In OS, we collected 40 oriented bricks from 5 sampling points inside the brickyard oven in order to test the stability and reliability of their remanent magnetizations by comparing them with the local field (measured directly with a fluxgate magnetometer). We observed differences of +/- 3° between the local field and the IGRF. When magnetic inclinations are reported relative to the flat planes of the brick (the situation we face for real ancient bricks), the differences due to inclination of the burning plane and magnetic anomalies inside the oven never exceed 6°. These differences are averaged out by using a minimum of 6 bricks (~24 specimens) per sampling point to compute the inclination. In the ancient site ECP we collected 140 non-oriented bricks from 14 different walls; three of them were previously dated using historical records. Inclinations were defined using at least 6 bricks per wall, showing consistent average values within the same walls. When compared to the IGRF and GUFM1 models, the inclinations obtained for the dated walls agreed within the experimental error. We have then applied the same procedure to estimate the age of the remaining walls. Using

Effectiveness of pavement-solar energy system – An experimental study

International Nuclear Information System (INIS)

Zhou, Zhihua; Wang, Xiaojuan; Zhang, Xiaoyan; Chen, Guanyi; Zuo, Jian; Pullen, Stephen

2015-01-01

Highlights: • We built a small-scale pilot project of pavement-solar energy utilization. • Design an automatic monitoring system to record the operating data. • The average heat absorptivity of pavement-solar energy is 37%. • The average thermal storage effectiveness of the system is 17%. - Abstract: A small-scale pilot project was built for the pavement-solar energy utilization in this paper. An automatic data acquisition system was designed to measure the effectiveness of the pavement solar energy system based on the operation data of 24 h a day in both summer and winter. Through 69 days (1656 h) of operation in summer, 2821 kW h of heat energy were stored in soil underground. In the transitional season, 4598 kW h of heat energy were taken out from soil during 104 days (2496 h) of operation in winter. The analysis showed that in summer, solar heat collection of asphalt pavement could effectively reduce 7 °C of its temperature. Under conditions of natural radiation, the average heat absorptivity of pavement was 37% and the average thermal storage effectiveness of the system was 17%. The electrical energy consumed by the system is only 11% of stored heat. During the winter, the asphalt pavement absorbs heat from underground soil which effectively increases its temperature, cutting 32% days of surface temperature below the freezing point. This not only save the energy for ice/snow removal but also mitigate associated safety risks

Pulmonary dysfunctions, oxidative stress and DNA damage in brick kiln workers.

Science.gov (United States)

Kaushik, R; Khaliq, F; Subramaneyaan, M; Ahmed, R S

2012-11-01

Brick kilns in the suburban areas in developing countries pose a big threat to the environment and hence the health of their workers and people residing around them. The present study was planned to assess the lung functions, oxidative stress parameters and DNA damage in brick kiln workers. A total of 31 male subjects working in brick kiln, and 32 age, sex and socioeconomic status matched controls were included in the study. The lung volumes, capacities and flow rates, namely, forced expiratory volume in first second (FEV(1)), forced vital capacity (FVC), FEV(1)/FVC, expiratory reserve volume, inspiratory capacity (IC), maximal expiratory flow when 50% of FVC is remaining to be expired, maximum voluntary ventilation, peak expiratory flow rate and vital capacity were significantly decreased in the brick kiln workers. Increased oxidative stress as evidenced by increased malonedialdehyde levels and reduced glutathione content, glutathione S-transferase activity and ferric reducing ability of plasma were observed in the study group when compared with controls. Our results indicate a significant correlation between oxidative stress parameters and pulmonary dysfunction, which may be due to silica-induced oxidative stress and resulting lung damage.

Developing a network-level structural capacity index for structural evaluation of pavements.

Science.gov (United States)

2013-03-01

The objective of this project was to develop a structural index for use in network-level pavement evaluation to facilitate : the inclusion of the pavements structural condition in pavement management applications. The primary goal of network-level...

Assessment of occupational health problems and physiological stress among the brick field workers of West Bengal, India.

Science.gov (United States)

Das, Banibrata

2014-06-01

The brick field industry is one of the oldest industries in India, which employs a large number of workers of poor socioeconomic status. The main aim of the present investigation is i) to determine the prevalence of musculoskeletal disorders among brick field workers, ii) to determine the prevalence of respiratory disorders and physiological stress among brick field workers compared to control workers. For this study, a total of 220 brick field workers and 130 control subjects were selected randomly. The control subjects were mainly involved in hand-intensive jobs. The Modified Nordic Questionnaire was applied to assess the discomfort felt among both groups of workers. Thermal stress was also assessed by measuring the WBGT index. The pulmonary functions were checked using the spirometry. Physiological assessment of the workload was carried out by recording the heart rate and blood pressure of the workers prior to work and just after work in the field. Brick field workers suffered from pain especially in the lower back (98%), hands (93%), knees (86%), wrists (85%), shoulders (76%) and neck (65%). Among the brick-making activities, brick field workers felt discomfort during spading for mud collection (98%), carrying bricks (95%) and molding (87%). The results showed a significantly lower p value workers compared to the control group. The post-activity heart rate of the brick field workers was 148.6 beats/min, whereas the systolic and diastolic blood pressure results were 152.8 and 78.5 mm/Hg, respectively. This study concludes that health of the brick field workers was highly affected due to working in unhealthy working conditions for a long period of time.

Low-Btu coal gasification in the United States: company topical. [Brick producers

Energy Technology Data Exchange (ETDEWEB)

Boesch, L.P.; Hylton, B.G.; Bhatt, C.S.

1983-07-01

Hazelton and other brick producers have proved the reliability of the commercial size Wellman-Galusha gasifier. For this energy intensive business, gas cost is the major portion of the product cost. Costs required Webster/Hazelton to go back to the old, reliable alternative energy of low Btu gasification when the natural gas supply started to be curtailed and prices escalated. Although anthracite coal prices have skyrocketed from $34/ton (1979) to over $71.50/ton (1981) because of high demand (local as well as export) and rising labor costs, the delivered natural gas cost, which reached $3.90 to 4.20/million Btu in the Hazelton area during 1981, has allowed the producer gas from the gasifier at Webster Brick to remain competitive. The low Btu gas cost (at the escalated coal price) is estimated to be $4/million Btu. In addition to producing gas that is cost competitive with natural gas at the Webster Brick Hazelton plant, Webster has the security of knowing that its gas supply will be constant. Improvements in brick business and projected deregulation of the natural gas price may yield additional, attractive cost benefits to Webster Brick through the use of low Btu gas from these gasifiers. Also, use of hot raw gas (that requires no tar or sulfur removal) keeps the overall process efficiency high. 25 references, 47 figures, 14 tables.

Assessment of environmental pollution from brick kilns and their impacts on human health in Bangladesh

International Nuclear Information System (INIS)

Azad, A.K.; Iqbal, A.

2005-01-01

Bricks are the most essential component for expanding urbanization in Bangladesh. Brick kilns situated all over the country meet the demand of these bricks. But brick fields are causing some environmental problems too. The objective of this study is to identify the pattern of energy consumption in brick fields as well as their impacts on the environment. An attempt has been made to estimate the emission of pollutants (Green house gases and non- green house gases) from brick fields to assess the impacts of the pollutants on human health of the surrounding areas. In Bangladesh, the total number of brick fields is around 6000. Brick fields use coal, wood fuel and crude a mainly for burning bricks in the kiln. Estimation reveals that in Bangladesh for the years 2003-2004, the coal required was 1800 kton while the wood fuel required was 1260 kton. Estimation also reveals that for Bangladesh the annual emission of the pollutants are 7505931.01 tons CO/sub 2/, 943.93 tons CH/sub 4/, 128.40 tons N/sub 2/O, 21763.49 tons NO/sub x/, 40777.21 tons CO, 1698.48 tons NMVOC and 176223.04 tons SO/sub 2/. CO/sub 2/ emission is the most prominent from brick burning. Estimation shows that, for the present level of CO/sub 2/ emission in Bangladesh yearly afforestation required is about 1.4 x 10/sup 9/9 m/sup 2/ area. The emission causes some health problems among both the workers and local inhabitants. The concentration persist around brick fields (200 m) is very high and is 3000 micro g/m/sup 3/ for SO/sub 2/ and 300 micro g/m/sup 3/ for NO/sub x/ and PM-10 during winter, while for summer the concentration is 1000 micro g/m/sup 3/ and 125 micro g/m/sup 3/ respectively. From the high concentration of these pollutants people face some of the health problems. About 30% of the workers suffer from dizziness while 60% feel fatigue. The headache is the most common problem of all the workers and 75% suffer from it. Those working for many years feel fatigue more than the new comers, 55% and 3

Surface sedimentation at permeable pavement systems

DEFF Research Database (Denmark)

Støvring, Jan; Dam, Torben; Jensen, Marina Bergen

2018-01-01

Newly installed permeable pavement (PP) systems provide high surface infiltration capacity, but the accumulation of sediments causes a decrease in capacity over time, eventually leading to surface clogging. With the aim of investigating local sedimentation processes and the importance of restorat......Newly installed permeable pavement (PP) systems provide high surface infiltration capacity, but the accumulation of sediments causes a decrease in capacity over time, eventually leading to surface clogging. With the aim of investigating local sedimentation processes and the importance...

Feasibility of coal fly ash based bricks and roof tiles as construction materials: a review

Directory of Open Access Journals (Sweden)

Akhtar M.N.

2017-01-01

Full Text Available The aim of present study is to investigate about the potential use of coal fly ash along with other natural and solid wastes for the production of coal fly ash based bricks and roof tiles. The study is based on the comprehensive reviews available from the previous experimental data on coal fly ash based bricks and roof tiles. The study intendeds to provide the essential technical information and data for the use of fly ash mix with other solid wastes and reveal their suitability as construction materials. It has been found that samples were non-hazardous in nature and vigorously used as an additional construction materials and their compositions are perfectly fit to make the strong composite material for bricks and tiles. The three past studies have been demonstrated that, fly ash based bricks and roof tiles provides a sustainable supplement to the traditional clay bricks and roof tiles, that not only increases the efficiency of traditional bricks and roof tiles but also helps significantly to reduce the environmental issues associated with the disposal of these waste materials. In addition to this study highlights the potential use of fly ash for producing sustainable construction materials.

Evaluation of microcracking and chemical deterioration in concrete pavements.

Science.gov (United States)

1995-10-31

The major objective of this research project was to investigate the : chemistry and morphology of portland cement concrete pavements in : Iowa. The integrity of the various pavements was evaluated qualitatively, : based on the presence or absence of ...

Soil Properties And Pavement Performance In The Nigerian ...

African Journals Online (AJOL)

The geotechnical properties of the sub-structure of the Shagamu-Ore-Benin pavement were studied in an attempt to identifying the quality of construction materials and the pavement performance. The sub-structure soil materials were collected from the field and were taken to the laboratory for particle size analysis, Atterberg ...

Effects of occupational heat exposure on female brick workers in West Bengal, India

Science.gov (United States)

Sett, Moumita; Sahu, Subhashis

2014-01-01

Background Manual brick-manufacturing units in India engage a large number of female workers on a daily-wage basis for a period of 8 months per year. There are two groups of female workers in the brickfields: the brick molders and the brick carriers. These brickfields are mostly unorganized, and the workers are exposed to extreme conditions such as very high seasonal heat. The present trend of increasing temperatures, as a result of global warming and climate change, will put an additional burden on them. Objective This study aims to evaluate the effect of workplace heat exposure on the well-being, physiological load, and productivity of female brickfield workers in India. Design A questionnaire study (n=120), environmental temperature, and weekly work productivity analyses were evaluated for 8 months in the brickfields. Cardiac strain and walking speed (subset, n=40) were also studied and compared in hotter and colder days amongst the female brickfield workers. Results The subjects experience summer for about 5 months with additional heat stress radiating from the brick kiln. The weekly productivity data show a linear decline in productivity with increased maximum air temperature above 34.9°C. The cardiac parameters (peak heart rate (HRp), net cardiac cost (NCC), relative cardiac cost (RCC), and recovery heart rates) were significantly higher on hotter days (Wet Bulb Globe Temperature (WBGTout) index: 26.9°C to 30.74°C) than on cooler days (WBGTout index: 16.12°C to 19.37°C) for the brick molders; however, this is not the case for the brick carriers. As the brick carriers adapt to hotter days by decreasing their walking speed, their productivity decreases. Conclusion We conclude that high heat exposure in brickfields during summer caused physiological strain in both categories of female brickfield workers. A coping strategy employed by the brick carriers was to reduce their walking speed and thus lose part of their earnings. The lost productivity for every

Effects of occupational heat exposure on female brick workers in West Bengal, India.

Science.gov (United States)

Sett, Moumita; Sahu, Subhashis

2014-01-01

Manual brick-manufacturing units in India engage a large number of female workers on a daily-wage basis for a period of 8 months per year. There are two groups of female workers in the brickfields: the brick molders and the brick carriers. These brickfields are mostly unorganized, and the workers are exposed to extreme conditions such as very high seasonal heat. The present trend of increasing temperatures, as a result of global warming and climate change, will put an additional burden on them. This study aims to evaluate the effect of workplace heat exposure on the well-being, physiological load, and productivity of female brickfield workers in India. A questionnaire study (n=120), environmental temperature, and weekly work productivity analyses were evaluated for 8 months in the brickfields. Cardiac strain and walking speed (subset, n=40) were also studied and compared in hotter and colder days amongst the female brickfield workers. The subjects experience summer for about 5 months with additional heat stress radiating from the brick kiln. The weekly productivity data show a linear decline in productivity with increased maximum air temperature above 34.9°C. The cardiac parameters (peak heart rate (HRp), net cardiac cost (NCC), relative cardiac cost (RCC), and recovery heart rates) were significantly higher on hotter days (Wet Bulb Globe Temperature (WBGTout) index: 26.9°C to 30.74°C) than on cooler days (WBGTout index: 16.12°C to 19.37°C) for the brick molders; however, this is not the case for the brick carriers. As the brick carriers adapt to hotter days by decreasing their walking speed, their productivity decreases. We conclude that high heat exposure in brickfields during summer caused physiological strain in both categories of female brickfield workers. A coping strategy employed by the brick carriers was to reduce their walking speed and thus lose part of their earnings. The lost productivity for every degree rise in temperature is about 2% in the

Update to Permeable Pavement Research at the Edison ...

Science.gov (United States)

The EPA’s Urban Watershed Management Branch (UWMB) has been monitoring the permeable pavement demonstration site at the Edison Environmental Center, NJ since 2010. This site has three different types of permeable pavements including interlocking concrete permeable pavers, pervious concrete, and porous asphalt. The permeable pavements are limited to parking spaces while adjacent driving lanes are impermeable and drain to the permeable surfaces. The parking lot is instrumented for continuous monitoring with thermistors and water content reflectometers that measure moisture as infiltrate passes through the storage gallery beneath the permeable pavements into the underlying native soil. Each permeable surface of the parking lot has four lined sections that capture infiltrate in tanks for water quality analyses; these tanks are capable of holding volumes up to 4.1 m3, which represents up to 38 mm (1.5 in.) for direct rainfall on the porous pavement and runoff from adjacent driving lanes that drain into the permeable surface.Previous technical releases concerning the demonstration site focused on monitoring techniques, observed chloride and nutrient concentrations, surface hydrology, and infiltration and evaporation rates. This presentation summarizes these past findings and addresses current water quality efforts including pH, solids analysis, total organic carbon, and chemical oxygen demand. Stormwater runoff continues to be a major cause of water pollution in

Urban permeable pavement system design based on “sponge city” concept

Science.gov (United States)

Yu, M. M.; Zhu, J. W.; Gao, W. F.; Xu, D. P.; Zhao, M.

2017-08-01

Based on the “sponge city” concept, to implement the goal of building a city within the city to solve the sponge waterlogging, rational utilization of water resources, reduce water pollution this paper, combined with the city planning level in China, establishes the design system of city road flooding from the macro, medium and micro level, explore the design method of city water permeable pavement system, and has a practical significance the lower flood risk water ecological problems. On the macro level, we established an urban pavement sponge system under the regional ecological pattern by “spot permeable open space - low impact developing rain water road system - catchment area and catchment wetland”. On a medium level, this paper proposed the permeable suitability of pavement and the planning control indicators when combined with urban functional districts to conduct permeable pavement roads plans and controls. On micro level, the paper studied sponge technology design of permeable pavement from road structure, surface material, and other aspects aimed at the pavement permeability requirements.

Encapsulating fly ash and acidic process waste water in brick structure

International Nuclear Information System (INIS)

Koseoglu, K.; Polat, M.; Polat, H.

2010-01-01

Fly ash contains metals such as cadmium, iron, lead, aluminum and zinc in its structure in appreciable amounts. These metals can leach out into surface and ground waters if fly ash is not properly disposed of. A similar problem also exists for acidic process waste waters discharged by numerous industries. The purpose of this study was to utilize such wastes as additives in the production of construction quality bricks for the purpose of waste elimination. The bricks produced were subjected to flexural strength and water retention capacity tests along with heavy metal leaching experiments in order to determine the applicability of the procedure and the best possible recipes. This paper summarizes the results obtained in these tests along with the possible mechanisms involved in stabilizing the two wastes in the brick structure.

Influence of Waste Brick Powder in the Mechanical Properties of Recycled Aggregate Concrete

Directory of Open Access Journals (Sweden)

Viviana Letelier

2018-03-01

Full Text Available Brick and concrete are the main materials contributing to demolition and construction waste. Considering this precedent, the effects of using both residuals in medium strength concretes are analyzed. Waste brick powder is used as a cement replacement in three different levels: 5%, 10%, and 15%, and it is tested in concretes with no recycled aggregates and concretes with 30% of recycled coarse aggregates replacing natural ones. The compressive strength, the flexural strength, and modulus of elasticity are calculated and compared to a control concrete with no brick powder and no recycled aggregates. The effects of the simultaneous use of both residuals on the physical properties of the recycled concrete are highlighted. Results show that 15% of cement can be replaced by waste brick powder together with 30% of recycled aggregates without suffering significant losses in the strength of the final material when compared to a control concrete.

Development of Improved Mechanistic Deterioration Models for Flexible Pavements

DEFF Research Database (Denmark)

Ullidtz, Per; Ertman, Hans Larsen

1998-01-01

The paper describes a pilot study in Denmark with the main objective of developing improved mechanistic deterioration models for flexible pavements based on an accelerated full scale test on an instrumented pavement in the Danish Road Tessting Machine. The study was the first in "International...... Pavement Subgrade Performance Study" sponsored by the Federal Highway Administration (FHWA), USA. The paper describes in detail the data analysis and the resulting models for rutting, roughness, and a model for the plastic strain in the subgrade.The reader will get an understanding of the work needed...

Properties of Normal and Recycled Brick Aggregates for Production of Medium Range (25–30 MPa Structural Strength Concrete

Directory of Open Access Journals (Sweden)

Suvash Chandra Paul

2018-05-01

Full Text Available This study compares the properties of normal and recycled brick aggregates to produce a medium range (25–30 MPa compressive strength of structural grade concrete. Up to date, brick aggregates are commonly used in structural concrete in some South Asian and African countries. Many concrete structures which were built in the last century are made from brick aggregates and some of them are already in a position of ending of their service life. At the same time, population and economic growth is forcing the demolition of many old structures. Therefore, there is a huge flow of construction and demolition waste and thereby it is necessary to recycle the waste to overcome the problem of occupying the landfill sites. For this study, recycled brick aggregates were collected from the various demolished building sites and their physical and mechanical performance were then compared with the concrete made from normal brick aggregates. It is found that the mechanical properties of recycled brick concrete are comparable to that of normal brick aggregate at medium strength level. The production cost of recycled brick concrete is also found to be 10–12% lower than normal brick aggregates.

Effect of flood conditions on the deterioration of porous clay-based brick

Science.gov (United States)

Mol, L.; Tomor, A.

2017-12-01

Man-made materials represent an increasingly large proportion of geomaterials that are used to build up a rapidly expanding urbanised landscape. The deterioration of such materials is of increasing concern, in particular in light of the projected increase in storm and flood events and their associated high water levels. The effect of prolonged saturation in porous materials, man-made as well as natural, can lead to accelerated deterioration. This can be of particular concern for load-bearing structural materials, for example bridges. In this study, the effect of moisture movement has been investigated for brick masonry, as one of the most commonly used porous building materials. Saturation of brick masonry can be of particular concern for historical masonry, such as masonry arch bridges in conjunction with under increasing levels of long-term traffic loading. While flooding can lead to scour and sudden collapse of bridges, saturation can also lead to accelerated medium and long-term deterioration. A series of small-scale laboratory tests have been carried out on brick masonry to identify the effects of saturation on the material properties and changes in the rate of deterioration. Brick masonry prisms have been loaded to failure under quasi-static and long-term cyclic compression and monitored with the help of acoustic emission technique, accelerometers, linear variable differential transformers (LVDTs), permeametry and brick surface hardness measurements. Under quasi-static loading saturated samples showed significant reduction in the load capacity and increased fracture development. Under fatigue loading the number of cycles to failure reduced significantly for saturated specimens and characteristic changes in material parameters have been related to stages of fatigue deterioration. Test results indicated that increasing flood events can accelerate moisture-related deterioration in porous brick masonry.

Highway pavement failure induced by poor soil geotechnical ...

African Journals Online (AJOL)

X-ray diffraction studies showed the presence of abundant kaolinite peaks and a subdued goethite peak without any trace of montmorrilonite. The presence of excess fines in the pavement construction materials (soils) contributed to the failure of the highway pavement at this locality. The low CBR value is also a noted cause ...

Compressive behavior of energy-saving fired facing brick composite wall

Science.gov (United States)

Guo, Kai; Wu, Cai

2018-03-01

The energy-saving fired facing brick composite wall has a broad development prospects due to its merits of thermal insulation, energy conservation, beautiful, and natural. The construction and characteristics of this wall are introduced and analyzed in this paper. Experimental studies of samples are also conducted to investigate its compressive performance. The results show that the energy-saving fired facing brick composite wall has high compressive capacity. It has considerable application prospect, the study in this paper provides foundation to further studies.

Yearbook of the brick-making industry 1984. Ziegeleitechnisches Jahrbuch 1984

Energy Technology Data Exchange (ETDEWEB)

Schellbach, G

1984-01-01

The following problems of the field of brick baking technology are discussed: 1. Structure of the brick-making industry of West Germany; 2. Waste recovery and utilisation; 3. Tunnel furnace processes (projecting and optimisation; 4. Light mortar; 5. Interdependences between passive use of solar energy, heat storage capacity of a building, heating energy consumption and room climate; 6. Research activities of the Institut fuer Ziegelforschung Essen e.V.; 7. Pore structure for ceramic materials; 8. Documentation; 9. New technical developments.

Runoff on Pavements of Soil-Cement Blocks – an Experimental Boarding

Directory of Open Access Journals (Sweden)

Zegarra-Tarqui Jorge Luis

2015-01-01

Full Text Available The article evaluates the reduction of runoff in pavements constructed with rectangular blocks of soil-cement. The tests were conducted in a pilot pavement built with soil-cement blocks, seated in a metal box of 50 cm × 50 cm (area = 2500 cm2, with declivities of 1%, 3% and 5%. Mean intensities of 76.9 mm / I 117.7 mm / h were used, values close to the intensities calculated by intensity-frequency-duration (i-f- -d equation of the city of Salvador, Brazil, for return periods of 2 and 5 years, respectively. The medium runoff coefficient was C = 0.61, this value is close to the coefficient of pavement with rectangular blocks (C = 0.6 and it has a lower value than the coefficient for concrete block pavement (C = 0.78. On the other hand, considering that areas with more than 2500 cm2 are constituted by coupling of area units of 50 cm × 50 cm, the splash losses are part of the runoff, obtaining the coefficient Csuperficial + splashing, which showed values in the 0.74 to 0.89 range, these values were found close to the coefficient of concrete block pavement (C = 0.78 and below the concrete pavement (C = 0.95, respectively, but factors such as displacement time of runoff on surface, depressions on the surface, roughness of pavement, evaporation and others, should reduce this value. Then, the pavement of soil-cement blocks can be considered in the category of semi-permeable for the area size used.

Assessing Asphalt and Concrete Pavement Surface Texture in the Field

OpenAIRE

Saad I. Sarsam; Huda N. Al Shareef

2016-01-01

The incorporation of safety characteristics into the traditional pavement structural design or in the functional evaluation of pavement condition has not been established yet. The design has focused on the structural capacity of the roadway so that the pavement can withstand specific level of repetitive loading over the design life. On the other hand, the surface texture condition was neither included in the AASHTO design procedure nor in the present serviceability index measurements. The ...

Elucidating the effects of solar panel waste glass substitution on the physical and mechanical characteristics of clay bricks.

Science.gov (United States)

Lin, Kae-Long; Huang, Long-Sheng; Shie, Je-Lueng; Cheng, Ching-Jung; Lee, Ching-Hwa; Chang, Tien-Chin

2013-01-01

This study deals with the effect of solar panel waste glass on fired clay bricks. Brick samples were heated to temperatures which varied from 700-1000 degrees C for 6 h, with a heating rate of 10 degrees C min(-1). The material properties of the resultant material were then determined, including speciation variation, loss on ignition, shrinkage, bulk density, 24-h absorption rate, compressive strength and salt crystallization. The results indicate that increasing the amount of solar panel waste glass resulted in a decrease in the water absorption rate and an increase in the compressive strength of the solar panel waste glass bricks. The 24-h absorption rate and compressive strength of the solar panel waste glass brick made from samples containing 30% solar panel waste glass sintered at 1000 degrees C all met the Chinese National Standard (CNS) building requirements for first-class brick (compressive strengths and water absorption of the bricks were 300 kg cm(-2) and 10% of the brick, respectively). The addition of solar panel waste glass to the mixture reduced the degree of firing shrinkage. The salt crystallization test and wet-dry tests showed that the addition of solar panel waste glass had highly beneficial effects in that it increased the durability of the bricks. This indicates that solar panel waste glass is indeed suitable for the partial replacement of clay in bricks.

Exploration of Machine Learning Approaches to Predict Pavement Performance

Science.gov (United States)

2018-03-23

Machine learning (ML) techniques were used to model and predict pavement condition index (PCI) for various pavement types using a variety of input variables. The primary objective of this research was to develop and assess PCI predictive models for t...

Volumetric radioassay of lead bricks being considered for unrestricted release

International Nuclear Information System (INIS)

Gehrke, R.J.; Losinski, S.J.; Seal, G.L.

1995-01-01

The hardware, software, and a protocol have been developed for the screening of lead bricks for free release or recycle from the Idaho National Engineering Laboratory. The procedure for measuring the background from a sampling of ''clean'' lead bricks and for deducing the decision limits (in pCi/g) have been developed. At the decision limit, a radioactive lead brick would be detected with 95% confidence if it were present. The total and peak efficiencies of a 2.54-cm diameter x 2.54-cm high NaI(Tl) scintillation detector for the counting geometry of the present study were measured with a mixed radionuclide standard and calculated with a Monte Carlo program, CYLTRAN. The deduced decision limit for the counting conditions of the present study were 0.0588 pCi/g by analyzing the entire spectrum and 0.256 pCi/g by analyzing the 661-keV peak region for a 900-second count

The durability of fired brick incorporating textile factory waste ash and basaltic pumice

Energy Technology Data Exchange (ETDEWEB)

Binici, Hanifi [Kahramanmaras Sutcu Imam Univ., Kahramanmaras (Turkey). Dept. of Civil Engineering; Yardim, Yavuz [Epoka Univ., Tirana (Albania). Dept. of Civil Engineering

2012-07-15

This study investigates the durability of fired brick produced with additives of textile factories' waste ash and basaltic pumice. The effects of incorporating waste ash and basaltic pumice on durability and mechanical properties of the clay bricks were studied. Samples were produced with different ratios of the textile factories' waste ash and basaltic pumice added and at different fire temperatures of 700, 900, and 1 050 C for 8 h. The bricks with additives were produced by adding equal amounts of textile factories' waste ash and basaltic pumice, separately and together, with rates of 5, 10 and 20 wt.%. The produced samples were kept one year in sodium sulphate and sodium nitrate and tested under freezing - unfreezing and drying - wetting conditions. Then compression strength and mass loss of the samples with and without additives were investigated. The test results were compared with standards and results obtained from control specimens. The results showed that incorporations up to 10 wt.% of textile factories' waste ash and basaltic pumice is beneficial to the fired brick. Both textile factories' waste ash and basaltic pumice were suitable additives and could be used for more durable clay brick production at 900 C fire temperature. (orig.)

Experimental study on the influence of the opening in brick-masonry wall to seismic performance of reinforced concrete frame structures

Science.gov (United States)

Maidiawati, Tanjung, Jafril; Medriosa, Hamdeni

2017-10-01

Reinforced concrete (RC) frame structures with brick-masonry infills are commonly used in developing countries and high-risk seismic area, such as Indonesia. Significant researches have been carried out for studying the seismic performance of RC frame structures with brick-masonry infills. Only few of them focused on effects of the opening in the brick-masonry infill to the seismic performance of the RC frame structures. The presence of opening in brick-masonry infill is often used for placing doors and windows as well, however, it may reduce the seismic performance of the RC frame structure. In the current study, they influence of the opening in brick-masonry infills to the seismic performance RC frame structure will experimentally evaluated. Five of 1/4-scaled single story and single bay RC frame specimens were prepared, i.e. an RC bare frame, a clay brick-masonry infilled RC frame and three of clay brick-masonry infilled RC frame with openings in the brick-masonry infills. The last three specimens were clay brick infilled RC frame with a center opening, clay brick infilled RC frame with two openings used for placing the windows and clay brick infilled RC frame with opening for placing the door. The specimens pushed over by applying the static monotonic lateral load to the upper beam of the RC frame structures. The incremental of the lateral load and the lateral displacement of RC frame's column was recorded during test. The crack propagation and the major cracks were also observed to identify the mechanism failure of specimens. As the results, the opening in the brick-masonry wall controls the failure mechanism, the lateral strength and the stiffness of the overall of infilled RC frame structure. The diagonal shear crack pattern was found on brick-masonry wall without opening, on other hand the different crack patterns were observed on brick-masonry wall with openings. Although the opening in the brick masonry infill reduced the lateral strength and stiffness of

Towards Understanding Tyre-Pavement Contact in APT Research on Flexible Pavements

CSIR Research Space (South Africa)

De Beer, Morris

2016-09-01

Full Text Available An important element of Accelerated Pavement Testing (APT) is the selection of appropriate test tyre(s) to be used for APT testing. By far the majority of full scale (or scaled) APT devices uses pneumatic rubber tyres. Tyres differ not only in size...

Tactile pavement for guiding walking direction: An assessment of heading direction and gait stability.

Science.gov (United States)

Pluijter, Nanda; de Wit, Lieke P W; Bruijn, Sjoerd M; Plaisier, Myrthe A

2015-10-01

For maintaining heading direction while walking we heavily rely on vision. Therefore, walking in the absence of vision or with visual attention directed elsewhere potentially leads to dangerous situations. Here we investigated whether tactile information from the feet can be used as a (partial) substitute for vision in maintaining a stable heading direction. If so, participants should be better able to keep a constant heading direction on tactile pavement that indicates directionality than on regular flat pavement. However, such a pavement may also be destabilizing. Thus we asked participants to walk straight ahead on regular pavement, and on tactile pavement (tiles with ridges along the walking direction) while varying the amount of vision. We assessed the effects of the type of pavement as well as the amount of vision on the variability of the heading direction as well as gait stability. Both of these measures were calculated from accelerations and angular velocities recorded from a smartphone attached to the participants trunk. Results showed that on tactile pavement participants had a less variations in their heading direction than on regular pavement. The drawback, however, was that the tactile pavement used in this study decreased gait stability. In sum, tactile pavement can be used as a partial substitute for vision in maintaining heading direction, but it can also decrease gait stability. Future work should focus on designing tactile pavement that does provided directional clues, but is less destabilizing. Copyright © 2015 Elsevier B.V. All rights reserved.

A Review of Permeable Pavement Clogging Investigations and Recommended Maintenance Regimes

Directory of Open Access Journals (Sweden)

Mostafa Razzaghmanesh

2018-03-01

Full Text Available Understanding clogging mechanisms in permeable pavements can help optimize the required maintenance regime. In this review paper, methods for investigating clogging mechanisms are described. These include surface infiltration methods, the use of embedded sensors, and the development of modelling tools. Previously conducted surface infiltration tests indicate the importance of the age of a permeable pavement system and also local climatic conditions, including rainfall intensity. The results indicate that porous concrete generally has the highest infiltration capacity and this is followed by permeable interlocking concrete pavement and then porous asphalt. The measured infiltration rates decreased significantly even within two years of installation. There was an indirect relationship between surface infiltration rates and the age of the pavements. It was also found that the rainfall characteristics are important in selecting the type of pavement. Sensor technologies have been used mainly in the United States and there has been a reluctance to use such technologies in other parts of the world. Few studies have been conducted into modelling the changing performance of permeable pavement systems over time and there is a need to develop more general models. Various methods and machinery have been developed for cleaning and maintaining permeable pavements and there is no universally preferred approach currently available. Indeed, several of the commonly used maintenance methods have been shown to be relatively ineffective.

Modeling the Hydrologic Processes of a Permeable Pavement System

Science.gov (United States)

A permeable pavement system can capture stormwater to reduce runoff volume and flow rate, improve onsite groundwater recharge, and enhance pollutant controls within the site. A new unit process model for evaluating the hydrologic performance of a permeable pavement system has be...

Development of low thermal conductivity brick using rice husk, corn cob and waste tea in clay brick manufacturing

Science.gov (United States)

Saman, Nor Sarwani Mat; Deraman, Rafikullah; Hamzah, Mohamad Hazmi

2017-12-01

The consumption of energy for cooling the indoor environment of buildings in Malaysia is high and mostly related to poor thermal performance of the building envelope. It is evident that reducing energy consumption of buildings has become vital, taking into considerations the limitation of conventional energy resources and the adverse effects associated with the use of such type of energy on the environment. Therefore, selecting the proper thermal properties of a building envelope play a major role in determining the energy consumption patterns and comfort conditions in enclosed spaces. The objective of this study is to investigate the potential application of rice husk (RH), corn cob (CC) and waste tea (WT) as an additive agent in a fired clay brick manufacturing to produce an improved thermal conductivity of final brick product. In the execution of this study, these agricultural wastes were mixed together with clay soil in different percentages, ranging from 0 %, 2.5 %, 5 %, 7.5 % and 10 % by weight. Physical and mechanical properties including soil physical properties, density, shrinkage, water absorption, compressive strength as well as thermal conductivity were measured, reported and discussed in accordance with BS 1377: Part 2: 1990, BS 3921: 1985, MS 76: 1972: Part 2 and ASTM C 518. The results show that RH at 7.5 % is the most effective combination to achieve low thermal conductivity of fired clay brick. This finding suggests that RH waste is a potentially good additive material to be used for thermal properties enhancement of the building envelope.

Characterizing Pavement Surface Distress Conditions with Hyper-Spatial Resolution Natural Color Aerial Photography

Directory of Open Access Journals (Sweden)

Su Zhang

2016-05-01

Full Text Available Roadway pavement surface distress information is critical for effective pavement asset management, and subsequently, transportation management agencies at all levels (i.e., federal, state, and local dedicate a large amount of time and money to routinely evaluate pavement surface distress conditions as the core of their asset management programs. However, currently adopted ground-based evaluation methods for pavement surface conditions have many disadvantages, like being time-consuming and expensive. Aircraft-based evaluation methods, although getting more attention, have not been used for any operational evaluation programs yet because the acquired images lack the spatial resolution to resolve finer scale pavement surface distresses. Hyper-spatial resolution natural color aerial photography (HSR-AP provides a potential method for collecting pavement surface distress information that can supplement or substitute for currently adopted evaluation methods. Using roadway pavement sections located in the State of New Mexico as an example, this research explored the utility of aerial triangulation (AT technique and HSR-AP acquired from a low-altitude and low-cost small-unmanned aircraft system (S-UAS, in this case a tethered helium weather balloon, to permit characterization of detailed pavement surface distress conditions. The Wilcoxon Signed Rank test, Mann-Whitney U test, and visual comparison were used to compare detailed pavement surface distress rates measured from HSR-AP derived products (orthophotos and digital surface models generated from AT with reference distress rates manually collected on the ground using standard protocols. The results reveal that S-UAS based hyper-spatial resolution imaging and AT techniques can provide detailed and reliable primary observations suitable for characterizing detailed pavement surface distress conditions comparable to the ground-based manual measurement, which lays the foundation for the future application

Analytical methods for the characterization of surface finishing in bricks

International Nuclear Information System (INIS)

Nardini, I.; Zendri, E.; Biscontin, G.; Brunetin, A.

2006-01-01

The recent restoration works of Santo Stefano Church Facade (XV century) in Venice have shown traces variously saved of different kind of surface finishes. These finishes were found on the brick's surface both in the masonry and in the decorative elements. Different brick's surface and decorative tile samples were investigated using several techniques: optical microscopy, scanning electron-microscopy, thermal analysis, infrared spectroscopy and reflectance Fourier transform infrared microspectroscopy. The evaluation of the reached results was used to understand the decorative techniques and to recognize the material employed

GHG emission quantification for pavement construction projects using a process-based approach

Directory of Open Access Journals (Sweden)

Charinee Limsawasd

2017-03-01

Full Text Available Climate change and greenhouse gas (GHG emissions have attracted much attention for their impacts upon the global environment. Initiating of new legislation and regulations for control of GHG emissions from the industrial sectors has been applied to address this problem. The transportation industries, which include operation of road pavement and pavement construction equipment, are the highest GHG-emitting sectors. This study presents a novel quantification model of GHG emissions of pavement construction using process-based analysis. The model is composed of five modules that evaluate GHG emissions. These are: material production and acquisition, (2 material transport to a project site, (3 heavy equipment use, (4 on-site machinery use, and, (5 on-site electricity use. The model was applied to a hypothetical pavement project to compare the environmental impacts of flexible and rigid pavement types during construction. The resulting model can be used for evaluation of environmental impacts, as well as for designing and planning highway pavement construction.

Utilization of Advanced Diagnostic Methods for Texture and Rut Depth Analysis on a Testing Pavement Section

Directory of Open Access Journals (Sweden)

Slabej Martin

2015-05-01

Full Text Available Qualitative characteristics of pavement in wide range reflects the pavement serviceability, which is a summary of the characteristics of the pavement, providing a fast, smooth, economical and especially safe driving of motor-vehicles. The target factor of pavement serviceability and safety of roads represents the quality of their surface properties. In the framework of research activities performed in the Research Centre founded under the auspices of University of Žilina, individual parameters of pavement serviceability were monitored by pavement surface scanning. This paper describes the creation of a 3D - road surface model and its analysis and evaluation from the viewpoint of two pavement serviceability parameters - the rut depth and texture. Measurements were performed on an experimental pavement section used contemporary in an Accelerated Pavement Testing experiment. The long-term goal is to ascertain functions predicting degradation of these two pavement serviceability parameters.

"Full-Scale Testing of Pavement Response"

DEFF Research Database (Denmark)

Ullidtz, Per; Ekdahl, Peter

1998-01-01

Three pavement sections in southern Sweden were instrumented in late 1991. Each section have instruments for measuring the strain at the bottom of the asphalt layer, vertical stress and strains in the subgrade and temperatures at different depths. The purpose was to evaluate different theoretical...... methods for determining stresses, strains and deflections in pavement structurers.Falling Weight Deflectometer (FWD) test were done on the test sections, and stresses and strains were measured both under FWD loading and under a rolling wheel load. Different back-analysis procedures were used to derive...

Cloud Impacts on Pavement Temperature in Energy Balance Models

Science.gov (United States)

Walker, C. L.

2013-12-01

Forecast systems provide decision support for end-users ranging from the solar energy industry to municipalities concerned with road safety. Pavement temperature is an important variable when considering vehicle response to various weather conditions. A complex, yet direct relationship exists between tire and pavement temperatures. Literature has shown that as tire temperature increases, friction decreases which affects vehicle performance. Many forecast systems suffer from inaccurate radiation forecasts resulting in part from the inability to model different types of clouds and their influence on radiation. This research focused on forecast improvement by determining how cloud type impacts the amount of shortwave radiation reaching the surface and subsequent pavement temperatures. The study region was the Great Plains where surface solar radiation data were obtained from the High Plains Regional Climate Center's Automated Weather Data Network stations. Road pavement temperature data were obtained from the Meteorological Assimilation Data Ingest System. Cloud properties and radiative transfer quantities were obtained from the Clouds and Earth's Radiant Energy System mission via Aqua and Terra Moderate Resolution Imaging Spectroradiometer satellite products. An additional cloud data set was incorporated from the Naval Research Laboratory Cloud Classification algorithm. Statistical analyses using a modified nearest neighbor approach were first performed relating shortwave radiation variability with road pavement temperature fluctuations. Then statistical associations were determined between the shortwave radiation and cloud property data sets. Preliminary results suggest that substantial pavement forecasting improvement is possible with the inclusion of cloud-specific information. Future model sensitivity testing seeks to quantify the magnitude of forecast improvement.

Effects on evaporation rates from different water-permeable pavement designs.

Science.gov (United States)

Starke, P; Göbel, P; Coldewey, W G

2011-01-01

The urban water balance can be attenuated to the natural by water-permeable pavements (WPPs). Furthermore, WPPs have a 16% higher evaporation rate than impermeable pavements, which can lead to a better urban climate. Evaporation rates from pavements are influenced by the pavement surface and by the deeper layers. By a compared evaporation measurement between different WPP designs, the grain size distribution of the sub-base shows no influence on the evaporation rates in a significant way. On the contrary, a sub-base made of a twin-layer decreases the evaporation by 16% compared to a homogeneous sub-base. By a change in the colour of the paving stone, 19% higher evaporation rates could be achieved. A further comparison shows that the transpiration-effect of the grass in grass pavers increases the evaporation rates more than threefold to pervious concrete pavements. These high evapotranspiration rates can not be achieved with a pervious concrete paving stone. In spite of this, the broad field of application of the pervious concrete paving stone increases the importance in regard to the urban climate.

A new method to determine thermophysical properties of PCM-concrete brick

DEFF Research Database (Denmark)

Cheng, Rui; Pomianowski, Michal Zbigniew; Wang, Xin

2013-01-01

. The equivalent specific heat distributions of 4 wt% and 6 wt% PCM-concrete brick were determined using this method. We found that the accuracy (the relative error of the calculated cp based on the inverse problem and their real values ranges from 10.43% to 19.4%) was acceptable for engineering use...... the shortcomings of using traditional testing methods to measure thermophysical properties of PCM-concrete brick. We then proposed a new method based on the inverse problem, which deals with the measurements of thermal conductivity and specific heat of PCM-concrete brick during the phase change process....... The influences of the temperature segments span and optimization algorithms were analyzed. The results showed that the Sequential Quadric Programming (SQP) method provides the highest accuracy and least complexity compared with the Particle Swarm Optimization and Genetic Optimization methods. Finally, we...

Advanced Automated Detection Analysis and Classification of Cracks in Pavement

OpenAIRE

Scott, Dennis

2014-01-01

Functional Session 5: Pavement Management Moderated by Akyiaa Hosten This presentation was held at the Pavement Evaluation 2014 Conference, which took place from September 15-18, 2014 in Blacksburg, Virginia. Presentation only

Effects of coal and wheat husk additives on the physical, thermal and mechanical properties of clay bricks

Energy Technology Data Exchange (ETDEWEB)

Ahmad, S.; Iqbal, Y.; Muhammad, R.

2017-07-01

The use of by-products as additives in brick industry is gaining increased research attention due to their effective role in decreasing the total energy needs of industrial furnaces. In addition, these additives leave pores upon burning, causing a decrease in thermal conductivity and affect the mechanical properties of bricks as well. In the present study, various proportions of coal and wheat husk were used as additives in the initial ingredients of clay bricks. Microstructure, thermal conductivity, coefficient of thermal diffusivity, water absorption, shrinkage, compressive strength and bulk density of fired clay bricks with and without additives were investigated. Clay bricks containing 5–15wt.% additives were found to be within the permissible limits for most of the recommended standard specifications. (Author)

Effect of interlayer bonding quality of asphalt layers on pavement performance

Science.gov (United States)

Jaskula, Piotr; Rys, Dawid

2017-09-01

The quality of interlayer bonding at the interfaces between the asphalt layers in flexible pavements affects the overall pavement performance. Lack or partial lack of interlayer bonding between asphalt layers can cause pavement’s premature failures such as rutting, slippage of the wearing course, cracking or simply a reduction in the calculated fatigue life of the pavement structure. This paper shows the case studies of investigation of actual or potential premature failure of newly reconstructed and constructed pavements where low quality of interlayer bonding has a dominant meaning. In situ and laboratory tests were performed and followed by analytical calculation of pavement structure where thicknesses of layers and maximum shear strengths obtained from the tests were used. During the investigation it was found out that a low quality of tack coat as well as the same aggregate gradation in the bonded asphalt mixtures were the main reasons behind the weak quality of interlayer bonding. Partial interlayer bonding has a strong influence on reduction of calculated fatigue life of pavement. The summary of the paper includes recommendations on how to avoid the low quality of interlayer bonding of asphalt layers.

Numerical simulation on the thermal response of heat-conducting asphalt pavements

Energy Technology Data Exchange (ETDEWEB)

Wang Hong; Wu Shaopeng; Chen Mingyu; Zhang Yuan, E-mail: wusp@whut.edu.c [Key Laboratory of Silicate Materials Science and Engineering, Ministry of Education, Wuhan University of Technology, Wuhan 430070 (China)

2010-05-01

Using asphalt pavements as a solar collector is a subject of current interest all over the world because the sun provides a cheap and abundant source of clean and renewable energy, which can be captured by black asphalt pavements. A heat-conducting device is designed to absorb energy from the sun. In order to validate what parameters are critical in the asphalt collector, a finite element model is developed to predict the thermal response of the heat-conducting device compared to the conventional asphalt mixture. Some factors that may affect the asphalt pavement collector are considered, including the coefficient of heat conductivity of the asphalt pavement, the distance between pipes with the medium, water, and the pipe's diameter. Ultimately, the finite element model can provide pavement engineers with an efficient computational tool that can be a guide to the conductive asphalt solar collector's experiment in the laboratory.

Numerical simulation on the thermal response of heat-conducting asphalt pavements

International Nuclear Information System (INIS)

Wang Hong; Wu Shaopeng; Chen Mingyu; Zhang Yuan

2010-01-01

Using asphalt pavements as a solar collector is a subject of current interest all over the world because the sun provides a cheap and abundant source of clean and renewable energy, which can be captured by black asphalt pavements. A heat-conducting device is designed to absorb energy from the sun. In order to validate what parameters are critical in the asphalt collector, a finite element model is developed to predict the thermal response of the heat-conducting device compared to the conventional asphalt mixture. Some factors that may affect the asphalt pavement collector are considered, including the coefficient of heat conductivity of the asphalt pavement, the distance between pipes with the medium, water, and the pipe's diameter. Ultimately, the finite element model can provide pavement engineers with an efficient computational tool that can be a guide to the conductive asphalt solar collector's experiment in the laboratory.

Influence of temperature on fatigue life or reinforced pavement by whitetopping

Science.gov (United States)

Szydło, A.; Mackiewicz, P.

2018-05-01

The article presents the influence of temperature on the fatigue strength of concrete slabs used for reinforcing susceptible flexible pavement. In Poland, so far, there is no research on thermal interactions on concrete pavement. The article presents an analysis of various climatic conditions occurring in Poland and temperature distribution in concrete pavement. The dependence of daily temperature fluctuations on the temperatures appearing in the concrete slab was demonstrated. An analysis of thermal stresses in concrete slabs depending on their parameters was shown, and then fatigue life was determined. The applied 3DFEM model includes elements of contact, friction, and gravity in order to better approximate the behaviour of the board from temperature change. On this basis, the significant influence of cyclical daily temperature changes on the durability of the concrete pavement was indicated. The presented analyses can be applied to reinforcements of existing flexible pavements.

Automatic Pavement Crack Recognition Based on BP Neural Network

Directory of Open Access Journals (Sweden)

Li Li

2014-02-01

Full Text Available A feasible pavement crack detection system plays an important role in evaluating the road condition and providing the necessary road maintenance. In this paper, a back propagation neural network (BPNN is used to recognize pavement cracks from images. To improve the recognition accuracy of the BPNN, a complete framework of image processing is proposed including image preprocessing and crack information extraction. In this framework, the redundant image information is reduced as much as possible and two sets of feature parameters are constructed to classify the crack images. Then a BPNN is adopted to distinguish pavement images between linear and alligator cracks to acquire high recognition accuracy. Besides, the linear cracks can be further classified into transversal and longitudinal cracks according to the direction angle. Finally, the proposed method is evaluated on the data of 400 pavement images obtained by the Automatic Road Analyzer (ARAN in Northern China and the results show that the proposed method seems to be a powerful tool for pavement crack recognition. The rates of correct classification for alligator, transversal and longitudinal cracks are 97.5%, 100% and 88.0%, respectively. Compared to some previous studies, the method proposed in this paper is effective for all three kinds of cracks and the results are also acceptable for engineering application.

A pavement management research program for Oregon highways : final report.

Science.gov (United States)

1989-12-01

An extensive program was developed to measure pavement deflection skid resistance, and rideability throughout Oregon. The data from those "objective" measures were then evaluated for correlations with observed pavement distress and traffic factors. :...

Using a constructive pavement texture index for skid resistance screening

Directory of Open Access Journals (Sweden)

Chia-Pei Chou

2017-07-01

Full Text Available Skid resistance measurement is one of the major measurements used to assess road safety. Typical devices used for measuring skid resistance include single point checking type and continuous measurements type. However, conducting periodic full roadway network skid resistance survey can be a relatively time consuming and difficult task because of the limited water carrying capacity used by all kinds of devices, including the continuous types. On the contrary, measurement of pavement surface texture can be conducted easily and continuously by most profilers. This research investigates the relation between pavement skid resistance and surface texture. The focus is on the development of a texture index that can serve as a screening indicator to filter out the high-risk pavement sections for further skid resistance measurement. Two measuring devices, GripTester (GT and National Taiwan University laser profiler (NTU Profiler, were used to collect data on pavement skid resistance and texture in a network of 555 sections, respectively. The pavement texture index of the mean difference of elevation (MDE is calculated at a 1 mm profile interval, which is a very promising indicator to represent pavement skid resistance. Through a sensitivity study, the MDE threshold of 0.15 mm is observed to provide a relatively reasonable screening function that filters out 29.01% of the entire surveyed network for further skid resistance inspection. It averted more than 70% skid resistance measurement capacity of the entire network. The accuracy of correct judgment by the selected threshold is about 80%, only 3.78% of roadway sections considered for further inspection of the recommended list are not included. Keywords: Skid resistance, Pavement texture, Macrotexture, Laser profiler, GripTester

Transport-related CO2 effects of online and brick-and-mortar shopping

DEFF Research Database (Denmark)

Wiese, Anne; Toporowski, Waldemar; Zielke, Stephan

2012-01-01

This paper compares transport-related CO2 emissions of online and brick-and-mortar shopping based on supply, delivery, order and travel data related to one multi-channel clothing retailer. A sensitivity analysis sheds more light on how situational factors, such as the customers’ travel distances......, returns, the use of public transport modes and information behavior via different channels influence the outcome of this comparison. The results show that online retailing causes lower CO2 emissions under many conditions. Nevertheless, the brick-and-mortar channel is more environmentally friendly when...... travel distances are small. The radius for which brick-and-mortar shopping has an advantage increases when returns, shifts in the use of public transport and information behavior are also considered....

Evaluation of pavement skid resistance using high speed texture measurement

Directory of Open Access Journals (Sweden)

Jay N. Meegoda

2015-12-01

Full Text Available Skid resistance is an important parameter for highway designs, construction, management, maintenance and safety. The purpose of this manuscript is to propose the correlation between skid resistance, which is measured as skid resistance trailer, and mean profile depth (MPD or the macro surface texture, which is measured by vehicle mounted laser, so that highway agencies can predict the skid resistance of pavement without the use of expensive and time consuming skid resistance trailer, which also causes disruption of traffic in use. In this research skid numbers and MPD from 5 new asphalt pavements and 4 old asphalt pavements were collected using a locked wheel skid trailer and a vehicle mounted laser. Using the data collected, a correlation between the skid number (SN40R collected by locked wheel skid tester and the texture data or MPD collected by a vehicle mounted laser operating at highway speeds was developed. The proposed correlation for new pavements was positive for MPD values less than 0.75 mm to reach a peak SN40R value, then there was a negative correlation as the MPD increases until the MPD value was equal to 1.1 mm and beyond the MPD value of 1.1 mm to the maximum value of 1.4 mm, SN40R value remained almost constant. There were significant data scatter for the MPD value of 0.8 mm. To explain these results, water film thickness during the friction test was calculated and the critical MPD was defined. The effect of sealed water pool on the SN40R was discussed. The test result showed a similar trend for older asphalt pavements, but with lower SN40R values due to the polishing of pavement micro-texture by traffic. Hence, a reduction factor was proposed for older pavements based on cumulative traffic volume for the above correlation to predict the skid resistance of older pavements.

Experimental studies of the dilution of vehicle exhaust pollutants by environment-protecting pervious pavement.

Science.gov (United States)

Liu, Chung-Ming; Chen, Jui-Wen; Tsai, Jen-Hui; Lin, Wei-Shian; Yen, M-T; Chen, Ting-Hao

2012-01-01

This study determines whether environment-protecting pervious pavement can dilute pollutants immediately after emissions from vehicle. The turbulence-driven dry-deposition process is too slow to be considered in this aspect. The pavement used is the JW pavement (according to its inventors name), a high-load-bearing water-permeable pavement with patents in over 100 countries, which has already been used for more than 8 years in Taiwan and is well suited to replacing conventional road pavement, making the potential implementation of the study results feasible. The design of this study included two sets of experiments. Variation of the air pollutant concentrations within a fenced area over the JW pavement with one vehicle discharging emissions into was monitored and compared with results over a non-JW pavement. The ambient wind speed was low during the first experiment, and the results obtained were highly credible. It was found that the JW pavement diluted vehicle pollutant emissions near the ground surface by 40%-87% within 5 min of emission; whereas the data at 2 m height suggested that about 58%-97% of pollutants were trapped underneath the pavement 20 min after emission. Those quantitative estimations may be off by +/- 10%, if errors in emissions and measurements were considered. SO2 and CO2 underwent the most significant reduction. Very likely, pollutants were forced to move underneath due to the special design of the pavement. During the second experiment, ambient wind speeds were high and the results obtained had less credibility, but they did not disprove the pollutant dilution capacity of the JW pavement. In order to track the fate of pollutants, parts of the pavement were removed to reveal a micro version of wetland underneath, which could possibly hold the responsibility of absorbing and decomposing pollutants to forms harmless to the environment and human health.

Usage of digital image correlation in assessment of behavior of block element pavement structure

Science.gov (United States)

Grygierek, M.; Grzesik, B.; Rokitowski, P.; Rusin, T.

2018-05-01

In diagnostics of existing road pavement structures deflection measurements have fundamental meaning, because of ability to assess present stiffness (bearing capacity) of whole layered construction. During test loading the reaction of pavement structure to applied load is measured in central point or in a few points located along a straight on a 1.5 ÷ 1.8 m distance (i.e. Falling Weight Deflectometer) in similar spacing equal to 20 ÷ 30 cm. Typical measuring techniques are productive and precise enough for most common pavement structures such as flexible, semi-rigid and rigid. It should be noted that in experimental research as well as in pavements in complex stress state, measurement techniques allowing observation of pavement deformation in 3D would have been very helpful. A great example of that type of pavements is a block element pavement structure consisting of i.e. paving blocks or stone slabs. Due to high stiffness and confined ability of cooperation of surrounding block elements, in that type of pavements fatigue life is strongly connected with displacement distribution. Unfortunately, typical deflection measurement methods forefend displacement observations and rotation of single block elements like paving blocks or slabs. Another difficult problem is to carry out unmistakable analysis of cooperation between neighboring elements. For more precise observations of displacements state of block element pavements under a wheel load a Digital Image Correlation (DIC) was used. Application of this method for assessment of behavior of stone slabs pavement under a traffic load enabled the monitoring of deformations distribution and encouraged to formulate conclusions about the initiation mechanism and development of damages in this type of pavement structures. Results shown in this article were obtained in field tests executed on an exploited pavement structure with a surface course made of granite slabs with dimensions 0.5x1.0x0.14 m.

Mobile geographic information system solution for pavement condition surveys [summary].

Science.gov (United States)

2012-01-01

The State Materials Office (SMO) of the Florida : Department of Transportation (FDOT) performs : annual Pavement Condition Surveys (PCS) of : the Departments extensive pavement network. : This work is performed by single-person crews in : inertial...

Designing Base and Subbase to Resist Environmental Effects on Pavements

Science.gov (United States)

2018-02-02

MnDOTs current pavement thickness design procedures do not characterize the effects of subgrade soil frost susceptibility. Previous research indicates frost action is the most severe environmental factor on pavement performance. The most accepted ...

Use of Ground Penetrating Radar at the FAA's National Airport Pavement Test Facility

Science.gov (United States)

Injun, Song

2015-04-01

The Federal Aviation Administration (FAA) in the United States has used a ground-coupled Ground Penetrating Radar (GPR) at the National Airport Pavement Test Facility (NAPTF) since 2005. One of the primary objectives of the testing at the facility is to provide full-scale pavement response and failure information for use in airplane landing gear design and configuration studies. During the traffic testing at the facility, a GSSI GPR system was used to develop new procedures for monitoring Hot Mix Asphalt (HMA) pavement density changes that is directly related to pavement failure. After reviewing current setups for data acquisition software and procedures for identifying different pavement layers, dielectric constant and pavement thickness were selected as dominant parameters controlling HMA properties provided by GPR. A new methodology showing HMA density changes in terms of dielectric constant variations, called dielectric sweep test, was developed and applied in full-scale pavement test. The dielectric constant changes were successfully monitored with increasing airplane traffic numbers. The changes were compared to pavement performance data (permanent deformation). The measured dielectric constants based on the known HMA thicknesses were also compared with computed dielectric constants using an equation from ASTM D4748-98 Standard Test Method for Determining the Thickness of Bound Pavement Layers Using Short-Pulse Radar. Six inches diameter cylindrical cores were taken after construction and traffic testing for the HMA layer bulk specific gravity. The measured bulk specific gravity was also compared to monitor HMA density changes caused by aircraft traffic conditions. Additionally this presentation will review the applications of the FAA's ground-coupled GPR on embedded rebar identification in concrete pavement, sewer pipes in soil, and gage identifications in 3D plots.

Modification of Yellow River Sediment Based Stabilized Earth Bricks

Directory of Open Access Journals (Sweden)

Junxia Liu

2016-12-01

Full Text Available This paper presents an experimental study on the microstructure and performance of stabilized earth bricks prepared from the Yellow River sediment. The sediment is modified by inorganic cementitious material, polymer bonding agent, and jute fibre. The results show that the sediment is preliminarily consolidated when the mixture ratio of activated sediment/cementitious binder/sand is 65/25/10. Compressive strength and softening coefficient of stabilized earth bricks is further improved by polymer bonding agent and jute fibre. SEM images and EDS spectral analysis indicate that there is indeed synergy among inorganic hydration products, polymer network and jute fibre to strengthen the sediment.

ANALYSIS OF GROUP MAINTENANCE STRATEGY -ROAD PAVEMENT AND SEWERAGE PIPES-

Science.gov (United States)

Tanimoto, Keishi; Sugimoto, Yasuaki; Miyamoto, Shinya; Nada, Hideki; Hosoi, Yoshihiko

Recently, it is critical to manage deteriorating sewerage and road facilities efficiently and strategically. Since the sewerage pipes are mostly installed under road pavement, the works for the replacement of the sewerage pipes are partially common to the works for the road. This means that the replacement cost can be saved by coordinating the timing of the replacements by sewerage pipe and road pavement. The purpose of the study is to develop the model based on Markov decision process to derive the optimal group maintenance policy so as to minimize lifecycle cost. Then the model is applied to case study area and demonstrated to estimate the lifecycle cost using statistical data such as pipe replacement cost, road pavement rehabilitation cost, and state of deterioration of pipes and road pavement.

ICP experiments more durable pavements

International Nuclear Information System (INIS)

Carta Petrolera

1994-01-01

A new asphalts technology that will make more durable the pavement in the highways and roads of the cities of Colombia investigates the Colombian Institute of the Petroleum ICP. The project that will have important incidence in the solution of one of the main problems in the roads of cities like Bogota, is only one of the 35 investigation programs and application of new technologies that with relationship to the sector of the hydrocarbons and its influence branches the ICP advances. The investigation looks for to elevate the current average of useful life of the pavements, with that it would be reached a standard that has the developed countries in this field

Inverse Analysis of Pavement Structural Properties Based on Dynamic Finite Element Modeling and Genetic Algorithm

Directory of Open Access Journals (Sweden)

Xiaochao Tang

2013-03-01

Full Text Available With the movement towards the implementation of mechanistic-empirical pavement design guide (MEPDG, an accurate determination of pavement layer moduli is vital for predicting pavement critical mechanistic responses. A backcalculation procedure is commonly used to estimate the pavement layer moduli based on the non-destructive falling weight deflectometer (FWD tests. Backcalculation of flexible pavement layer properties is an inverse problem with known input and output signals based upon which unknown parameters of the pavement system are evaluated. In this study, an inverse analysis procedure that combines the finite element analysis and a population-based optimization technique, Genetic Algorithm (GA has been developed to determine the pavement layer structural properties. A lightweight deflectometer (LWD was used to infer the moduli of instrumented three-layer scaled flexible pavement models. While the common practice in backcalculating pavement layer properties still assumes a static FWD load and uses only peak values of the load and deflections, dynamic analysis was conducted to simulate the impulse LWD load. The recorded time histories of the LWD load were used as the known inputs into the pavement system while the measured time-histories of surface central deflections and subgrade deflections measured with a linear variable differential transformers (LVDT were considered as the outputs. As a result, consistent pavement layer moduli can be obtained through this inverse analysis procedure.

Software offers transparent, straightforward assessment of pavement additives : research spotlight.

Science.gov (United States)

2015-04-01

Adding new materials to pavement layers is a proven technique to : improve performance. Many types of additivesfrom engineered : polymers and acids to recycled pavement, crumb rubber, shingles : and glasshave been used to help construct better ...

Evaluation of recycled concrete as aggregate in new concrete pavements.

Science.gov (United States)

2014-04-01

This study evaluated the use of recycled concrete as coarse aggregate in new concrete pavements. : Recycled concrete aggregate (RCA) produced from demolished pavements in three geographically dispersed locations in Washington state were used to perfo...

Evaluation of concrete pavements with materials-related distress : appendix B.

Science.gov (United States)

2010-02-02

An evaluation of cores sampled from six concrete pavements was performed. Factors contributing to pavement distress observed in the field were determined, including expansive alkali-silica reactivity and freeze-thaw deterioration related to poor entr...

Evaluation of concrete pavements with materials-related distress : appendix C.

Science.gov (United States)

2010-03-02

An evaluation of cores sampled from six concrete pavements was performed. Factors contributing to pavement distress observed in the field were determined, including expansive alkali-silica reactivity and freeze-thaw deterioration related to poor entr...

Pavement system with rubber tire chips in subgrade

Energy Technology Data Exchange (ETDEWEB)

Ashtakala, B.; Hoque, A.K.M.M. [Concordia Univ., Montreal, PQ (Canada). Dept. of Civil Engineering

1995-12-31

A pavement design method was developed in which shredded rubber tire chips mixed with sand were used as a material for pavement subgrade. Rubber tire chips are highly compressible and produce both elastic and plastic deformations under the application of loads. Sand was added to fill the void between the tire chips and make the mixture a strong material. The design method considered the vertical compressive strain produced by the design life traffic load 18k (80 KN) repetitions. The equivalent thicknesses of the layers above the subgrade corresponding to this vertical compressive strain were determined using contour charts. From this equivalent thickness, the thicknesses for asphalt pavement, base, and sub-base were determined by Odemark`s method. 3 refs., 1 tab., 3 figs.

Rheo-mechanical model for self-healing asphalt pavement

International Nuclear Information System (INIS)

Gömze, A L; Gömze, L N

2017-01-01

Examining the rheological properties of different asphalt mixtures at different temperatures, pressures and deformation conditions on the combined rheo-tribometers the authors have found that the generally used Burgers-model doesn’t explain the deformation properties of asphalt mixtures and pavements under loading forces and loading pressures. To understand better the rheological and deformation properties of such complex materials like asphalt mixtures and pavements the authors used Malvern Mastersizer X laser granulometer, Bruker D8 Advance X-ray diffractometer, Hitachi TM 1000 Scanning Elektronmicroscope, Tristar 3000 specific surface tester and the combined rheo-tribometer developed and patented by the authors. After the complex investigation of different asphalt mixtures the authors have found a new, more complex rheological model for the asphalts including self-healing asphalt pavements. (paper)

Damage to historic brick masonry structures. Masonry damage diagnostic system and damage atlas for evaluation of deterioration

NARCIS (Netherlands)

Balen, K. van; Binda, L.; Hees, R.P.J. van; Franke, L.

1996-01-01

The aim of the research on brick masonry degradation supported by the D.G. XII is presented. The project is delivering the following: ► Damage Atlas of ancient brick masonry, a book with a description of the types of damage, and their possible causes, in ancient brick masonry structures; ► Masonry

29 CFR 570.64 - Occupations involved in the manufacture of brick, tile, and kindred products (Order 13).

Science.gov (United States)

2010-07-01

... 29 Labor 3 2010-07-01 2010-07-01 false Occupations involved in the manufacture of brick, tile, and... Detrimental to Their Health or Well-Being § 570.64 Occupations involved in the manufacture of brick, tile, and... term clay construction products shall mean the following clay products: Brick, hollow structural tile...

Assessing artificial neural network performance in estimating the layer properties of pavements

Directory of Open Access Journals (Sweden)

Gloria Inés Beltran

2014-05-01

Full Text Available A major concern in assessing the structural condition of existing flexible pavements is the estimation of the mechanical properties of constituent layers, which is useful for the design and decision-making process in road management systems. This parameter identification problem is truly complex due to the large number of variables involved in pavement behavior. To this end, non-conventional adaptive or approximate solutions via Artificial Neural Networks – ANNs – are considered to properly map pavement response field measurements. Previous investigations have demonstrated the exceptional ability of ANNs in layer moduli estimation from non-destructive deflection tests, but most of the reported cases were developed using synthetic deflection data or hypothetical pavement systems. This paper presents further attempts to back-calculate layer moduli via ANN modeling, using a database gathered from field tests performed on three- and four-layer pavement systems. Traditional layer structuring and pavements with a stabilized subbase were considered. A three-stage methodology is developed in this study to design and validate an “optimum” ANN-based model, i.e., the best architecture possible along with adequate learning rules. An assessment of the resulting ANN model demonstrates its forecasting capabilities and efficiency in solving a complex parameter identification problem concerning pavements.

Greenhouse Gas Emissions from Asphalt Pavement Construction: A Case Study in China.

Science.gov (United States)

Ma, Feng; Sha, Aimin; Lin, Ruiyu; Huang, Yue; Wang, Chao

2016-03-22

In China, the construction of asphalt pavement has a significant impact on the environment, and energy use and greenhouse gas (GHG) emissions from asphalt pavement construction have been receiving increasing attention in recent years. At present, there is no universal criterion for the evaluation of GHG emissions in asphalt pavement construction. This paper proposes to define the system boundaries for GHG emissions from asphalt pavement by using a process-based life cycle assessment method. A method for evaluating GHG emissions from asphalt pavement construction is suggested. The paper reports a case study of GHG emissions from a typical asphalt pavement construction project in China. The results show that the greenhouse gas emissions from the mixture mixing phase are the highest, and account for about 54% of the total amount. The second highest GHG emission phase is the production of raw materials. For GHG emissions of cement stabilized base/subbase, the production of raw materials emits the most, about 98%. The GHG emission for cement production alone is about 92%. The results indicate that any measures to reduce GHG emissions from asphalt pavement construction should be focused on the raw materials manufacturing stage. If the raw materials production phase is excluded, the measures to reduce GHG emissions should be aimed at the mixture mixing phase.

Integrating Pavement Crack Detection and Analysis Using Autonomous Unmanned Aerial Vehicle Imagery

Science.gov (United States)

2015-03-27

INTEGRATING PAVEMENT CRACK DETECTION AND ANALYSIS USING AUTONOMOUS UNMANNED AERIAL VEHICLE...protection in the United States. AFIT-ENV-MS-15-M-195 INTEGRATING PAVEMENT CRACK DETECTION AND ANALYSIS USING AUTONOMOUS UNMANNED AERIAL...APPROVED FOR PUBLIC RELEASE; DISTRIBUTION UNLIMITED. AFIT-ENV-MS-15-M-195 INTEGRATING PAVEMENT CRACK DETECTION AND ANALYSIS USING AUTONOMOUS

Preliminary study on immobilization of buffing dust by solidification method in ceramic brick

Science.gov (United States)

Yuliansyah, Ahmad Tawfiequrrahman; Prasetya, Agus; Putra, Arif Eka; Satriawan, Humam Budi

2017-11-01

Leather-based industries generate a substantial amount of hazardous solid and liquid wastes in their process. One of the solid wastes is buffing dust, which is fine particulates containing fat, tanning, dyes and chromium. From 1 ton of leather processed, approximately 2-6 kg of buffing dust is generated. Chromium in the buffing dust is carcinogenic, so a proper handling is highly required. Solidification is a method commonly used to immobilize toxic material. Hence, the material is trapped in a matrix made of binding agents to minimize its mobility. However, a very small amount of the materials is sometimes released to the environment during storage. This study investigates leaching process of chromium from immobilized buffing dust in ceramic brick. Buffing dust, which contains chromium, is solidified by mixing it with clay at certain compositions and fired in a muffle furnace to produce a ceramic brick. Performance of the solidification process is evaluated by measuring the leaching of chromium in the leaching test. The results show that the solidification has significantly reduced the potential release of chromium to the environment. Higher of the firing temperature, less chromium is leached from ceramic brick. The chromium concentration of leachate water from 800°C brick is 0.376 ppm, while those from 850 and 900°C brick are 0.212 and 0.179 ppm respectively.

Bond Behavior of Historical Clay Bricks Strengthened with Steel Reinforced Polymers (SRP)

Science.gov (United States)

Grande, Ernesto; Imbimbo, Maura; Sacco, Elio

2011-01-01

In the strengthening interventions of past and historical masonry constructions, the non-standardized manufacture processes, the ageing and the damage of masonry units, could significantly affect the properties of the surfaces where strengthening materials are applied. This aspect requires particular care in evaluating the performance of externally bonded strengthening layers, especially with reference to the detachment mechanism. The bond response of old masonries could be very different from that occurring in new masonry units which are the ones generally considered in most of the bond tests available in technical literature. The aim of the present paper is the study of the bond behavior of historical clay bricks strengthened with steel reinforced polymers (SRP) materials. In particular, the results of an experimental study concerning new manufactured clay bricks and old bricks extracted from different historical masonry buildings are presented. The obtained results, particularly in terms of bond resistance, detachment mechanism and strain distributions, are discussed for the purpose of analyzing the peculiarities of the historical bricks in comparison with new manufactured ones. Some considerations on the efficacy of the theoretical formulations of the recent Italian code are also carried out. PMID:28880008

Effect of Crushed Glass Cullet Sizes on Physical and Mechanical Properties of Red Clay Bricks

Directory of Open Access Journals (Sweden)

Patricia Ponce Peña

2016-01-01

Full Text Available This study reports the effect of clear waste glass from bottles added on 20 to 30 wt.% and variable particle size (<500, <300, and <212 μm, into clay mixtures for the handmade brick manufacturing process. The bricks were manufactured with mixtures of clay, crushed glass, and water in different proportions, homogenized, casted in wooden molds, air-dried at room temperature for 72 h, and sintered at 1000°C for 12 h. Total shrinkage, water absorption, compressive strength, microstructure, and phase composition are discussed with respect to glass content and its particle size. The results indicate that increasing the content of glass and decreasing its particle size enhanced significantly the brick properties of water absorption and compressive strength by up to 18.5% and 6.8 MPa, for bricks with 30 wt% and particle size lower than 212 μm. It is proposed that decreasing the glass particle size its surface area increases allowing easier melting of glass by lower energy consumption, reducing porosity and enhancing brick properties.

Pervious Pavement System Evaluation

Science.gov (United States)

Porous pavement is a low impact development stormwater control. The Urban Watershed Management Branch is evaluating interlocking concrete pavers as a popular implementation. The pavers themselves are impermeable, but the spaces between the pavers are backfilled with washed, grade...

The effect of loading time on flexible pavement dynamic response: a finite element analysis

Science.gov (United States)

Yin, Hao; Solaimanian, Mansour; Kumar, Tanmay; Stoffels, Shelley

2007-12-01

Dynamic response of asphalt concrete (AC) pavements under moving load is a key component for accurate prediction of flexible pavement performance. The time and temperature dependency of AC materials calls for utilizing advanced material characterization and mechanistic theories, such as viscoelasticity and stress/strain analysis. In layered elastic analysis, as implemented in the new Mechanistic-Empirical Pavement Design Guide (MEPDG), the time dependency is accounted for by calculating the loading times at different AC layer depths. In this study, the time effect on pavement response was evaluated by means of the concept of “pseudo temperature.” With the pavement temperature measured from instrumented thermocouples, the time and temperature dependency of AC materials was integrated into one single factor, termed “effective temperature.” Via this effective temperature, pavement responses under a transient load were predicted through finite element analysis. In the finite element model, viscoelastic behavior of AC materials was characterized through relaxation moduli, while the layers with unbound granular material were assumed to be in an elastic mode. The analysis was conducted for two different AC mixtures in a simplified flexible pavement structure at two different seasons. Finite element analysis results reveal that the loading time has a more pronounced impact on pavement response in the summer for both asphalt types. The results indicate that for reasonable prediction of dynamic response in flexible pavements, the effect of the depth-dependent loading time on pavement temperature should be considered.

Modelling of composite concrete block pavement systems applying a cohesive zone model

DEFF Research Database (Denmark)

Skar, Asmus; Poulsen, Peter Noe

This paper presents a numerical analysis of the fracture behaviour of the cement bound base material in composite concrete block pavement systems, using a cohesive zone model. The functionality of the proposed model is tested on experimental and numerical investigations of beam bending tests....... The pavement is modelled as a simple slab on grade structure and parameters influencing the response, such as analysis technique, geometry and material parameters are studied. Moreover, the analysis is extended to a real scale example, modelling the pavement as a three-layered structure. It is found...... block pavements. It is envisaged that the methodology implemented in this study can be extended and thereby contribute to the ongoing development of rational failure criteria that can replace the empirical formulas currently used in pavement engineering....

A comparison between linear and non-linear analysis of flexible pavements

Energy Technology Data Exchange (ETDEWEB)

Soleymani, H.R.; Berthelot, C.F.; Bergan, A.T. [Saskatchewan Univ., Saskatoon, SK (Canada). Dept. of Mechanical Engineering

1995-12-31

Computer pavement analysis programs, which are based on mathematical simulation models, were compared. The programs included in the study were: ELSYM5, an Elastic Linear (EL) pavement analysis program, MICH-PAVE, a Finite Element Non-Linear (FENL) and Finite Element Linear (FEL) pavement analysis program. To perform the analysis different tire pressures, pavement material properties and asphalt layer thicknesses were selected. Evaluation criteria used in the analysis were tensile strain in bottom of the asphalt layer, vertical compressive strain at the top of the subgrade and surface displacement. Results showed that FENL methods predicted more strain and surface deflection than the FEL and EL analysis methods. Analyzing pavements with FEL does not offer many advantages over the EL method. Differences in predicted strains between the three methods of analysis in some cases was found to be close to 100% It was suggested that these programs require more calibration and validation both theoretically and empirically to accurately correlate with field observations. 19 refs., 4 tabs., 9 figs.

Preliminary evaluation of the lifecycle costs and market barriers of reflective pavements; TOPICAL

International Nuclear Information System (INIS)

Ting, M.; Koomey, J.G.; Pomerantz, M.

2001-01-01

The objective of this study is to evaluate the life cycle costs and market barriers associated with using reflective paving materials in streets and parking lots as a way to reduce the urban heat island effect. We calculated and compared the life cycle costs of conventional asphalt concrete (AC) pavements to those of other existing pavement technologies with higher reflectivity-portland cement concrete (PCC), porous pavements, resin pavements, AC pavements using light-colored chip seals, and AC pavements using light-colored asphalt emulsion additives. We found that for streets and parking lots, PCC can provide a cost-effective alternative to conventional AC when severely damaged pavements must be completely reconstructed. We also found that rehabilitating damaged AC streets and intersections with thin overlays of PCC (ultra-thin white topping) can often provide a cost-effective alternative to standard rehabilitation techniques using conventional AC. Chip sealing is a common maintenance treatment for low-volume streets which, when applied using light-colored chips, could provide a reflective pavement surface. If the incremental cost of using light-colored chips is low, this chip sealing method could also be cost-effective, but the incremental costs of light-colored chips are as of yet uncertain and expected to vary. Porous pavements were found to have higher life cycle costs than conventional AC in parking lots, but several cost-saving features of porous pavements fell outside the boundaries of this study. Resin pavements were found to be only slightly more expensive than conventional AC, but the uncertainties in the cost and performance data were large. The use of light-colored additives in asphalt emulsion seal coats for parking lot pavements was found to be significantly more expensive than conventional AC, reflecting its current niche market of decorative applications. We also proposed two additional approaches to increasing the reflectivity of conventional AC

Effect of training algorithms on neural networks aided pavement ...

African Journals Online (AJOL)

Especially, the use of Finite Element (FE) based pavement modeling results for training the NN aided inverse analysis is considered to be accurate in realistically characterizing the non-linear stress-sensitive response of underlying pavement layers in real-time. Efficient NN learning algorithms have been developed and ...

Design of the First Italian Roundabout with Jointed Plain Concrete Pavement

Directory of Open Access Journals (Sweden)

Paola Di Mascio

2018-02-01

Full Text Available This work presents the results of the overall design of the first Italian roundabout with jointed plain concrete pavement. The examined case study complies with current international standards and practices for geometry of roundabouts and road pavements. The construction of a concrete pavement in an urban roundabout will better manage and slow down fast vehicular flows, and increase traffic fluidity in an important junction, trafficked by heavy vehicles, where maintenance works should be reduced to avoid queues. The design of the roundabout involved several competences for: defining the geometry of the four-arm junction, designing the thickness of the jointed plain concrete pavement both on the circular crown and the arms, studying the mix design of a high resistance concrete. As regard to the pavement, the result of the study was an un-dowelled concrete pavement composed of square slabs laid on a cement concrete subbase and a granular layer. The shape of the slabs has been designed to optimize the structural performance of their material, which is a high strength concrete mix derived from an extensive laboratory test work. In general, the results summarized approaches typical of different design conditions: urban ones for traffic flow and safety needs; high-traffic ones for the chosen pavement type; airport ones for the absence of dowel and tie bars at the joints. Indeed, the article has highlighted that the design process of a concrete roundabout requires multiple analyses to consider various features and correctly re-design an existing urban junction. Its geometrical design, the structural design of the concrete pavement and the theoretical and experimental design of the concrete mix were the main phases of this process and they needed different competences to conduct comprehensive and appropriate analyses.

Skid resistance determination for pavement management and wet-weather road safety

Directory of Open Access Journals (Sweden)

T.F. Fwa

2017-09-01

Full Text Available Road accidents during wet weather have been a topic of major concern of road engineers in regions of wet-tropical climate and in other parts of the world during the wet season of the year. Road safety studies indicate that approximately 20% of all road accidents occurred during wet weather, and that the skid resistance of wet pavements have a major influence on the occurrences of wet-weather accidents. Monitoring of wet pavement skid resistance has been an integral part of a typical pavement management system. However, because of the lack of prediction capability of pavement skid resistance under various rainfall intensities, the minimum skid resistance threshold for safe wet-weather driving has been specified by highway agencies based on either engineering judgement or past experience. It is shown in this paper that the single-point minimum skid resistance threshold is inadequate to offer a complete description of the skid resistance performance of the pavement sections in question for effective management of a road network. It is unable to assess the risk involved in an actual wet-weather condition where the pavement surface water-film thickness and vehicle speed are different from standard test conditions. This limitation of the current system of specifying a minimum skid resistance threshold can be overcome by adopting a theoretically sound approach to represent pavement skid resistance under different conditions of water-film thickness and vehicle speed. This paper describes the theoretical basis of the approach and the development of a mechanistically derived three-dimensional finite-element skid resistance simulation model to predict skid resistance. The application of the proposed approach and the skid resistance prediction procedure in pavement management system and wet-weather driving safety assessment is presented.

The use of a cubesat to validate technological bricks in space

Science.gov (United States)

Rakotonimbahy, E.; Vives, S.; Dohlen, K.; Savini, G.; Iafolla, V.

2017-11-01

In the framework of the FP7 program FISICA (Far Infrared Space Interferometer Critical Assessment), we are developing a cubesat platform which will be used for the validation in space of two technological bricks relevant for FIRI. The first brick is a high-precision accelerometer which could be used in a future space mission as fundamental element for the dynamic control loop of the interferometer. The second brick is a miniaturized version of an imaging multi-aperture telescope. Ultimately, such an instrument could be composed of numerous space-born mirror segments flying in precise formation on baselines of hundreds or thousands of meters, providing high-resolution glimpses of distant worlds. We are proposing to build a very first space-born demonstrator of such an instrument which will fit into the limited resources of one cubesat. In this paper, we will describe the detailed design of the cubesat hosting the two payloads.

Black carbon, organic carbon, and co-pollutant emissions and energy efficiency from artisanal brick production in Mexico

Science.gov (United States)

Zavala, Miguel; Molina, Luisa T.; Maiz, Pablo; Monsivais, Israel; Chow, Judith C.; Watson, John G.; Munguia, Jose Luis; Cardenas, Beatriz; Fortner, Edward C.; Herndon, Scott C.; Roscioli, Joseph R.; Kolb, Charles E.; Knighton, Walter B.

2018-04-01

In many parts of the developing world and economies in transition, small-scale traditional brick kilns are a notorious source of urban air pollution. Many are both energy inefficient and burn highly polluting fuels that emit significant levels of black carbon (BC), organic carbon (OC) and other atmospheric pollutants into local communities, resulting in severe health and environmental impacts. However, only a very limited number of studies are available on the emission characteristics of brick kilns; thus, there is a need to characterize their gaseous and particulate matter (PM) emission factors to better assess their overall contribution to emissions inventories and to quantify their ecological, human health, and climate impacts. In this study, the fuel-, energy-, and brick-based emissions factors and time-based emission ratios of BC, OC, inorganic PM components, CO, SO2, CH4, NOx, and selected volatile organic compounds (VOCs) from three artisanal brick kilns with different designs in Mexico were quantified using the tracer ratio sampling technique. Simultaneous measurements of PM components, CO, and CO2 were also obtained using a sampling probe technique. Additional measurements included the internal temperature of the brick kilns, mechanical resistance of bricks produced, and characteristics of fuels employed. Average fuel-based BC emission factors ranged from 0.15 to 0.58 g (kg fuel)-1, whereas BC/OC mass ratios ranged from 0.9 to 5.2, depending on the kiln type. The results show that both techniques capture similar temporal profiles of the brick kiln emissions and produce comparable emission factors. A more integrated inter-comparison of the brick kilns' performances was obtained by simultaneously assessing emissions factors, energy efficiency, fuel consumption, and the quality of the bricks produced.

Evaluation of mechanical design fire brick at test section on the HeaTiNG-02

International Nuclear Information System (INIS)

Dedy Haryanto; Riswan Djambiar; Sagino; Edy Sumarno

2013-01-01

The activity was carried out due to the modification of the heating in the HeaTiNG-02 test section. Modification of the heater needs to be done to overcome the obstacles that arise as part of the test section is used. Constraint that often arises is the fall of the heating source with super khantal material when it reaches a certain temperature. To mitigate the super khantal position is initially converted into a vertical position horizontal. The change from vertical to horizontal position on super khantal cause any deformities in refractory fire brick which serves as a support super khantal. Manufacture of refractory design fire brick formation and mechanical strength evaluation performed using CATIA V5 R20 software. Evaluation of fireproof rock mechanics to be based on the mechanical properties of alumina as a refractory material of fire brick. The results of the analysis have a fire brick design stress greater than the bend strength alumina materials, so that the necessary checks before and after the experiment as well as the replacement of refractory fire brick if something is broken. Translational greatest displacement 0.453 mm at a temperature of 1575 K did not give any meaningful form. Thus the refractory fire brick design can be used as heating source support in the HeaTiNG-02 test section with checks before and after the operation. (author)

Overview of the South African mechanistic pavement design analysis method

CSIR Research Space (South Africa)

Theyse, HL

1996-01-01

Full Text Available A historical overview of the South African mechanistic pavement design method, from its development in the early 1970s to the present, is presented. Material characterization, structural analysis, and pavement life prediction are discussed...

Density measurement verification for hot mix asphalt concrete pavement construction.

Science.gov (United States)

2010-06-01

Oregon Department of Transportation (ODOT) requires a minimum density for the construction of dense-graded hot mix asphalt concrete (HMAC) pavements to ensure the likelihood that the pavement will not experience distresses that reduce the expected se...

Density measurement verification for hot mixed asphalt concrete pavement construction.

Science.gov (United States)

2010-06-01

Oregon Department of Transportation (ODOT) requires a minimum density for the construction of dense-graded hot mix asphalt concrete (HMAC) pavements to ensure the likelihood that the pavement will not experience distresses that reduce the expected se...

A pavement management research program for Oregon highways : interim report.

Science.gov (United States)

1985-03-01

This is the first in a series of reports documenting progress on a statewide pavement management research project. The overall project is conducting research into pavement life cycles of different rehabilitation treatment; the cost-effectiveness of e...

Temperature prediction model of asphalt pavement in cold regions based on an improved BP neural network

International Nuclear Information System (INIS)

Xu, Bo; Dan, Han-Cheng; Li, Liang

2017-01-01

Highlights: • Pavement temperature prediction model is presented with improved BP neural network. • Dynamic and static methods are presented to predict pavement temperature. • Pavement temperature can be excellently predicted in next 3 h. - Abstract: Ice cover on pavement threatens traffic safety, and pavement temperature is the main factor used to determine whether the wet pavement is icy or not. In this paper, a temperature prediction model of the pavement in winter is established by introducing an improved Back Propagation (BP) neural network model. Before the application of the BP neural network model, many efforts were made to eliminate chaos and determine the regularity of temperature on the pavement surface (e.g., analyze the regularity of diurnal and monthly variations of pavement temperature). New dynamic and static prediction methods are presented by improving the algorithms to intelligently overcome the prediction inaccuracy at the change point of daily temperature. Furthermore, some scenarios have been compared for different dates and road sections to verify the reliability of the prediction model. According to the analysis results, the daily pavement temperatures can be accurately predicted for the next 3 h from the time of prediction by combining the dynamic and static prediction methods. The presented method in this paper can provide technical references for temperature prediction of the pavement and the development of an early-warning system for icy pavements in cold regions.

The Inhabitants of the Historical Pavement

DEFF Research Database (Denmark)

2016-01-01

and boulevards to kiosks and cigarette packs.This particular excerpt presents a framed view of a quasi-historical pavement in downtown Chicago and the coming and going of people. Some are passing by without paying much attention, for others it is their daily workplace and for some an exotic starting point...... for yet unknown adventures. The pavement and collective history will outlast all of them – but while they are here, they set each other in motion and even the most trivial elements of the street become part of this choreography.Throughout the film, the reciprocal relationship between the individual...

Decision of National and Provincial Highway Asphalt Pavement Structure Based on Value Engineering

Directory of Open Access Journals (Sweden)

Yingwei Ren

2014-01-01

Full Text Available It is important that decision of asphalt pavement structure requires overall considerations of the performance and financial investment. To have asphalt pavement structure fulfilling good reliability, the asphalt pavement structure decision was researched based on value engineering theory. According to the national and provincial highway investigation data in Shandong Province during the last decade, the asphalt pavement performance attenuation rules of traffic levels and asphalt layer thicknesses were developed, and then the road performance evaluation method was presented. In addition, the initial investments, the costs of road maintenance, and middle-scale repair in a period were analyzed. For the light traffic and medium traffic example, using the value engineering method, the pavement performance and costs of which thickness varies from 6 cm to 10 cm were calculated and compared. It was concluded that value engineering was an effective method in deciding the asphalt pavement structure.

Mechanics based model for predicting structure-induced rolling resistance (SRR) of the tire-pavement system

Science.gov (United States)

Shakiba, Maryam; Ozer, Hasan; Ziyadi, Mojtaba; Al-Qadi, Imad L.

2016-11-01

The structure-induced rolling resistance of pavements, and its impact on vehicle fuel consumption, is investigated in this study. The structural response of pavement causes additional rolling resistance and fuel consumption of vehicles through deformation of pavement and various dissipation mechanisms associated with inelastic material properties and damping. Accurate and computationally efficient models are required to capture these mechanisms and obtain realistic estimates of changes in vehicle fuel consumption. Two mechanistic-based approaches are currently used to calculate vehicle fuel consumption as related to structural rolling resistance: dissipation-induced and deflection-induced methods. The deflection-induced approach is adopted in this study, and realistic representation of pavement-vehicle interactions (PVIs) is incorporated. In addition to considering viscoelastic behavior of asphalt concrete layers, the realistic representation of PVIs in this study includes non-uniform three-dimensional tire contact stresses and dynamic analysis in pavement simulations. The effects of analysis type, tire contact stresses, pavement viscoelastic properties, pavement damping coefficients, vehicle speed, and pavement temperature are then investigated.

Development of index based pavement performance models for pavement management system (PMS) of LADOTD.

Science.gov (United States)

2009-03-01

This report focuses on pavement performance and treatment models for Louisiana Department of : Transportation and Development (LADOTD) and is in continuation of Louisiana Transportation : Research Center (LTRC) Report No. 430 Development of Unifor...

Recent rubber crumb asphalt pavement projects in Alberta

Energy Technology Data Exchange (ETDEWEB)

Soleyman, H.R. [Alberta Univ., Edmonton, AB (Canada). Dept. of Civil and Environmental Engineering; Pulles, B.C.M.; Treleaven, L.B. [EBA Engineering Consultants Ltd., Edmonton, AB (Canada)

2003-07-01

Several countries around the world have been using rubber crumb (RC) for pavement applications for more than 20 years. The performance of asphalt pavements is enhanced by the use of recycled tires, which has the added advantage of solving the problem of tire disposal. In 2002, the Tire Recycling Management Association of Alberta (TRMA) and Alberta Transportation (AT) evaluated the feasibility and performance of an overlay using asphalt rubber (AR) pavement in Alberta. A partnership in the project was formed by AT, the City of Calgary, the City of Edmonton, and Strathcona County, where each one paved one section of a road with AR in conjunction with a section using conventional or other asphalt mixture types. The roads selected were: (1) 112 Avenue North West in Calgary, (2) 17 Street and Baseline Road in Strathcona County, (3) 137 Avenue in Edmonton, and (4) highway 630 in the vicinity of North Cooking Lake (Alberta Transportation). Two different AR pavement thicknesses were used to study the effects of overlay thicknesses on the performance of the overlay. The structural and functional factors were monitored before, during and after the construction of all sections. The preliminary evaluation of the application of AR in Alberta was presented, along with a summary of test results and performances of AR pavement sections. A full freeze-thaw cycle is required (Spring 2003) before the results of the analysis of the testing are known. The reduced thickness AR sections performed in a similar manner to those with full thickness AC sections. 10 refs., 5 tabs., 3 figs.

Project Inner Brick - Colorful Plastic Bricks in Psychotherapy - An Introduction to Methodology

Directory of Open Access Journals (Sweden)

Neidert László

2015-06-01

Full Text Available PIB is a research project pertaining to the psychotherapeutic potential of Lego bricks. This is based on Lego Group’s own method called Lego Seriousplay and Eric Berne's transactional analysis as a theoretical background. If we see it from the Lego’s aspect, our plan is a training like LSP. It is only alike because of the special application. We made a lot of modifications according to the original methodology. In this document we would like to present details of our research we have been working on for almost two years. The characteristics of our methodology will be illustrated, too.

Mechanical performance of porous concrete pavement containing nano black rice husk ash

Science.gov (United States)

Ibrahim, M. Y. Mohd; Ramadhansyah, P. J.; Rosli, H. Mohd; Ibrahim, M. H. Wan

2018-01-01

This paper presents an experimental research on the performance of nano black rice husk ash on the porous concrete pavement properties. The performance of the porous concrete pavement mixtures was investigated based on their compressive strength, flexural strength, and splitting tensile strength. The results indicated that using nano material from black rice husk ash improved the mechanical properties of porous concrete pavement. In addition, the result of compressive, flexural, and splitting tensile strength was increased with increasing in curing age. Finally, porous concrete pavement with 10% replacement levels exhibited an excellent performance with good strength compared to others.

Accelerated load testing of geosynthetic base reinforced pavement test sections.

Science.gov (United States)

2011-02-01

The main objective of this research is to evaluate the benefits of geosynthetic stabilization and reinforcement of subgrade/base aggregate layers in flexible pavements built on weak subgrades and the effect of pre-rut pavement sections, prior to the ...

Numerical Study of Tire Hydroplaning Based on Power Spectrum of Asphalt Pavement and Kinetic Friction Coefficient

Directory of Open Access Journals (Sweden)

Shengze Zhu

2017-01-01

Full Text Available Hydroplaning is a driving phenomenon threating vehicle’s control stability and safety. It happens when tire rolls on wet pavement with high speed that hydrodynamic force uplifts the tire. Accurate numerical simulation to reveal the mechanism of hydroplaning and evaluate the function of relevant factors in this process is significant. In order to describe the friction behaviors of tire-pavement interaction, kinetic friction coefficient curve of tire rubber and asphalt pavement was obtained by combining pavement surface power spectrum and complex modulus of tread rubber through Persson’s friction theory. Finite element model of tire-fluid-pavement was established in ABAQUS, which was composed of a 225-40-R18 radial tire and three types of asphalt pavement covered with water film. Mechanical responses and physical behaviors of tire-pavement interaction were observed and compared with NASA equation to validate the applicability and accuracy of this model. Then contact force at tire-pavement interface and critical hydroplaning speed influenced by tire inflation pressure, water film thickness, and pavement types were investigated. The results show higher tire inflation pressure, thinner water film, and more abundant macrotexture enhancing hydroplaning speed. The results could be applied to predict hydroplaning speed on different asphalt pavement and improve pavement skid resistance design.

Performance of Kaolin Clay on the Concrete Pavement

Science.gov (United States)

Abdullah, M. E.; Jaya, R. P.; Shahafuddin, M. N. A.; Yaacob, H.; Ibrahim, M. H. Wan; Nazri, F. M.; Ramli, N. I.; Mohammed, A. A.

2018-05-01

This paper investigates the performance of concrete pavement containing kaolin clay with their engineering properties and to determine the optimum kaolin clay content. The concrete used throughout the study was designed as grade 30 MPa strength with constant water to cement ratio of 0.49. The compressive strength, flexural strength and water absorption test was conducted in this research. The concrete mix designed with kaolin clay as cement replacement comprises at 0%, 5%, 10% and 15% by the total weight of cement. The results indicate that the strength of pavement concrete decreases as the percentage of kaolin clay increases. It also shows that the water absorption increases with the percentage of cement replacement. However, 5% kaolin clay is found to be the optimum level to replace cement in a pavement concrete.

Investigation clogging dynamic of permeable pavement systems using embedded sensors

Science.gov (United States)

Permeable pavement is a stormwater control measure commonly selected in both new and retrofit applications. However, there is limited information about the clogging mechanism of these systems that effects the infiltration. A permeable pavement site located at the Seitz Elementary...

Moisture Content Numerical Simulation on Structural Damage of Hot Mix Asphaltic Pavement

Science.gov (United States)

Abejide, O. S.; Mostafa, M. M. H.

2017-06-01

Considering the merits of road transportation in the economy and communication activities of the modern societies, it is imperative to design a safe, stable, efficient and cost effective road that will lead to increased economic development and growth of the South African nation. Although, the overarching effect of failed roads has in many ways led to increased travel time, loss of life and property; leading to reduced driver control on failed road sections (riding quality). Thus, time rate delamination of flexible pavement is a major focus of this study. Since structural collapse in a flexible pavement structure is caused by the evolution of different types of damage mechanisms; fatigue cracking, advanced crushing, temperature variation, and delamination. The effect of moisture content on HMA was analysed. The analysis from the multi-layered elastic model indicates that increase in moisture content in the underlying layer of HMA pavement results to increase in the strain of the individual layers and culminates to a decrease in the structural carrying capacity of the pavement with respect to number of load cycles that can be carried on the HMA pavement. This study shows a clear relationship between the moisture/saturation coefficient and the Elastic Modulus of the underlying geometric material layer properties of the pavement during the service life of the pavement.

Corrosion resistance of cement brick on an organo-mineral base in a hydrogen sulfide medium

Energy Technology Data Exchange (ETDEWEB)

Potapov, A G; Belousov, G A; Pustovalov, V I; Skorikov, B M

1981-01-01

Results are presented of strength tests of cement brick made of different types of cement as a function of the composition of the mixing liquid and storage conditions. It is established that cement brick made of cement on a cinder base mixed in hydrogen sulfide water possesses the highest corrosive resistance to hydrogen sulfide attack. A marked increase in corrosion resistance is observed in cement brick on an organo-mineral base. Results of industrial tests of organo-mineral grouting mortar in a hydrogen sulfide medium are demonstrated.

Metamaterial bricks and quantization of meta-surfaces

Science.gov (United States)

Memoli, Gianluca; Caleap, Mihai; Asakawa, Michihiro; Sahoo, Deepak R.; Drinkwater, Bruce W.; Subramanian, Sriram

2017-02-01

Controlling acoustic fields is crucial in diverse applications such as loudspeaker design, ultrasound imaging and therapy or acoustic particle manipulation. The current approaches use fixed lenses or expensive phased arrays. Here, using a process of analogue-to-digital conversion and wavelet decomposition, we develop the notion of quantal meta-surfaces. The quanta here are small, pre-manufactured three-dimensional units--which we call metamaterial bricks--each encoding a specific phase delay. These bricks can be assembled into meta-surfaces to generate any diffraction-limited acoustic field. We apply this methodology to show experimental examples of acoustic focusing, steering and, after stacking single meta-surfaces into layers, the more complex field of an acoustic tractor beam. We demonstrate experimentally single-sided air-borne acoustic levitation using meta-layers at various bit-rates: from a 4-bit uniform to 3-bit non-uniform quantization in phase. This powerful methodology dramatically simplifies the design of acoustic devices and provides a key-step towards realizing spatial sound modulators.

GPR used in combination with other NDT methods for assessing pavements in PPP projects

Science.gov (United States)

Loizos, Andreas; Plati, Christina

2014-05-01

In the recent decades, Public-Private Partnerships (PPP) has been adopted for highway infrastructure procurement in many countries. PPP projects typically take the form of a section of highway and connecting roadways which are to be construction and managed for a given concession period. Over the course of the highway concession period, the private agency takes over the pavement maintenance and rehabilitation duties. On this purpose, it is critical to find the most cost effective way to maintain the infrastructure in compliance with the agreed upon performance measures and a Pavement Management Systems (PMS) is critical to the success of this process. For the prosperous operation of a PMS it is necessary to have appropriate procedures for pavement monitoring and evaluation, which is important in many areas of pavement engineering. Non Destructive Testing (NDT) has played a major role in pavement condition monitoring, assessments and evaluation accomplishing continuous and quick collection of pavement data. The analysis of this data can lead to indicators related to trigger values (criteria) that define the pavement condition based on which the pavement "health" is perceived helping decide whether there is the need or not to intervene in the pavement. The accomplished perception appoints required management activities for preserving pavements in favor not only of the involved highway/road agencies but also of users' service. Amongst NDT methods Ground Penetrating Radar (GPR) seems to be a very powerful toll, as it provides a range of condition and construction pavement information. It can support effectively the implementation of PMS activities in the framework of pavement monitoring and evaluation. Given that, the present work aims to the development and adaptation of a protocol for the use of GPR in combination with other NDT methods, such as Falling Weight Deflectometer (FWD), for assessing pavements in PPP projects. It is based on the experience of Laboratory of

"Bricks and mortar" self-assembly approach to graphitic mesoporous carbon nanocomposites

Energy Technology Data Exchange (ETDEWEB)

Fulvio, P. F.; Mayes, R.; Wang, X. Q.; Mahurin, S., M.; Bauer, J. C.; Presser, V.; McDonough, J.; Gogotsi, Y.; Dai, S.

2011-04-20

Mesoporous carbon materials do not have sufficient ordering at the atomic scale to exhibit good electronic conductivity. To date, mesoporous carbons having uniform mesopores and high surface areas have been prepared from partially-graphitizable precursors in the presence of templates. High temperature thermal treatments above 2000 °C, which are usually required to increase conductivity, result in a partial or total collapse of the mesoporous structures and reduced surface areas induced by growth of graphitic domains, limiting their applications in electric double layer capacitors and lithium-ion batteries. In this work, we successfully implemented a “brick-and-mortar” approach to obtain ordered graphitic mesoporous carbon nanocomposites with tunable mesopore sizes below 850 °C without using graphitization catalysts or high temperature thermal treatments. Phenolic resin-based mesoporous carbons act as mortar to highly conductive carbon blacks and carbon onions (bricks). The capacitance and resistivity of final materials can be tailored by changing the mortar to brick ratios.

Use of dry sludge from waste water treatment plants as an additive in prefabricated concrete brick

OpenAIRE

Yagüe, A.; Valls, S.; Vázquez, E.; Kuchinow, V.

2002-01-01

Dry sludge from the Sabadell Water Treatment Plant was used to prepare prefabricated concrete bricks. After characterising the sludge and the manufacturing process used to make the bricks, we define the conditions of addition of the sludges in the manufacture. Reference samples not containing sludge and samples containing 2 % of dry sludge by cement weight were prepared. The variation in density, porosity, absorption coefficient and compressive strength of the bricks with the presence of...

The use of accelerometers in the pavement performance monitoring and analysis

International Nuclear Information System (INIS)

Ryynaenen, T; Belt, J; Pellinen, T

2010-01-01

This study investigated the use of sensor technology to enhance the management of highway infrastructure. With the help of monitoring data, it is possible to assess the current analytical pavement analysis method, which is based on multi-layered elastic analysis, and, thus enhance the pavement design practices in use. Pavement response was measured using different sensors, installed at various depths. Most promising sensors for the continuous monitoring purposes were the accelerometers. The drawback of these sensors is that the measured quantity is acceleration, which must be converted to the deflection via mathematical integration. In this paper some issues related to the manipulation of accelerometer data is presented and discussed, in addition of the discussion of the calculated and measured pavement response.

Determination of coefficient of thermal expansion for Portland Cement Concrete pavements for MEPDG Implementation

Science.gov (United States)

2012-10-01

The Coefficient of Thermal Expansion (CTE) is an important parameter in Portland Cement Concrete (PCC) pavement analysis and design as it is directly proportional to the magnitude of temperature-related pavement deformations throughout the pavement s...

Innovative CO2 LASER-Based Pavement Striping and Stripe Removal

Science.gov (United States)

2014-07-01

This is a Technical Report of an FY2014 NDOT funded project on Innovative CO2 Laserbased Pavement Striping and Stripe Removal. The project was concerned with adopting the laser technology for pavement stripe and markers removal and inferring on its e...

Experimental continuously reinforced concrete pavement parameterization using nondestructive methods

Directory of Open Access Journals (Sweden)

L. S. Salles

Full Text Available ABSTRACT Four continuously reinforced concrete pavement (CRCP sections were built at the University of São Paulo campus in order to analyze the pavement performance in a tropical environment. The sections short length coupled with particular project aspects made the experimental CRCP cracking be different from the traditional CRCP one. After three years of construction, a series of nondestructive testing were performed - Falling Weight Deflectometer (FWD loadings - to verify and to parameterize the pavement structural condition based on two main properties: the elasticity modulus of concrete (E and the modulus of subgrade reaction (k. These properties estimation was obtained through the matching process between real and EverFE simulated basins with the load at the slab center, between two consecutive cracks. The backcalculation results show that the lack of anchorage at the sections end decreases the E and k values and that the longitudinal reinforcement percentage provides additional stiffness to the pavement. Additionally, FWD loadings tangential to the cracks allowed the load transfer efficiency (LTE estimation determination across cracks. The LTE resulted in values above 90 % for all cracks.

The use of whitetopping technology in the aspect of implementation of repairs of flexible pavements

Directory of Open Access Journals (Sweden)

Tomasz Rudnicki

2016-09-01

Full Text Available This paper presents an analysis of technical and economic implementation of repairs of bituminous pavements using whitetopping technology at the example of classical jointed solutions and the continuous reinforcement. The problems of repairs of asphalt roads in the context of steadily progressive degradation of flexible pavements in Poland are discussed.The types of pavement constructions were presented, with particular emphasis on characteristics of flexible pavements. There were identified and described significant factors contributing to damage, which consequently lead to surface degradation. Also there have been described the types of concrete pavements and their characteristics, taking into account modern technology of cement concrete overlays made in various technologies. The results of the analysis of technical and economic implementation of repairs of flexible pavements using whitetopping technology are presented at the example of classical jointed solutions and the continuous reinforcement. The benefits and potential difficulties in the implementation of pavements repairs as cement concrete technology are indicated.[b]Keywords[/b]: road, repair, whitetopping, overlay, flexible surface, cement concrete pavement, continuous reinforcement

Caltrans accelerated pavement testing (CAL/APT) program - test results: 1993-1996

CSIR Research Space (South Africa)

Nokes, WA

1997-08-01

Full Text Available By combining the results of both the HVS and laboratory tests, interpretations of pavement performance are described and recommendations for pavement design and construction have been made to Caltrans....

Assessment of asphalt concrete reinforcement grid in flexible pavements : final report.

Science.gov (United States)

2016-05-01

This report investigated the application of accepted methods of pavement structural evaluation to independently assess the potential structural benefit of asphalt geogrid reinforcement of an operational flexible highway pavement. The asphalt interlay...

Pavement cells and the topology puzzle.

Science.gov (United States)

Carter, Ross; Sánchez-Corrales, Yara E; Hartley, Matthew; Grieneisen, Verônica A; Marée, Athanasius F M

2017-12-01

D'Arcy Thompson emphasised the importance of surface tension as a potential driving force in establishing cell shape and topology within tissues. Leaf epidermal pavement cells grow into jigsaw-piece shapes, highly deviating from such classical forms. We investigate the topology of developing Arabidopsis leaves composed solely of pavement cells. Image analysis of around 50,000 cells reveals a clear and unique topological signature, deviating from previously studied epidermal tissues. This topological distribution is established early during leaf development, already before the typical pavement cell shapes emerge, with topological homeostasis maintained throughout growth and unaltered between division and maturation zones. Simulating graph models, we identify a heuristic cellular division rule that reproduces the observed topology. Our parsimonious model predicts how and when cells effectively place their division plane with respect to their neighbours. We verify the predicted dynamics through in vivo tracking of 800 mitotic events, and conclude that the distinct topology is not a direct consequence of the jigsaw piece-like shape of the cells, but rather owes itself to a strongly life history-driven process, with limited impact from cell-surface mechanics. © 2017. Published by The Company of Biologists Ltd.

Investigation of isothermal water infiltration into fired clay brick by scattered neutrons

International Nuclear Information System (INIS)

El Abd, A.; Abdel-Monem, A.M.; Kansouh, W.A.

2012-01-01

A method based on neutron scattering was proposed to investigate isothermal water infiltration in porous media. Two different kinds of fired clay bricks were investigated. While the sample absorb water, scattered neutrons from the different wetted regions, along the flow direction were continuously recorded. The results were discussed in terms of the theory of water infiltration in unsaturated porous media as well as by an anomalous diffusion approach. It was shown that the infiltration process in the Canadian clay brick (CCB) is Fickian and the water diffusivity was analytically determined, while it is non-Fickian in the Egyptian clay brick (ECB). The infiltration process in ECB can be modeled as a two stage Fickian process, at the low and high absorption times. The anomalous diffusion approach failed to describe the diffusion process in the ECB at all water contents. (author)

Consumers Attitudes towards Internet and Brick and Mortar Store Channels Switching Behavior

Directory of Open Access Journals (Sweden)

Abdolrazagh MADAHI

2014-12-01

Full Text Available he purpose of this study is to examine the role of consumers’ behavioral attitude and intention toward channel switching behavior in regards to Internet and brick and mortar store channels in Malaysia. The survey instrument administered to the Malaysian consumers from regions of Klang Valley and Penang. A total of 497 completed surveys were obtained. Partial least squares (PLS based structural equation modeling (SEM technique was used to analyze data. A total of 497 completed surveys were obtained. Findings showed that compatibility and complexity were significant in predicting attitude in regard to switching channel from Internet to brick and mortar store. Relative advantage and compatibility were relevant in predicting attitude in brick and mortar store channel. Attitude also significantly affected channel switching intention regarding to both channels. Our findings reveal that gender and intention significantly affect channel switching behavior.

Urban pavement surface temperature. Comparison of numerical and statistical approach

Science.gov (United States)

Marchetti, Mario; Khalifa, Abderrahmen; Bues, Michel; Bouilloud, Ludovic; Martin, Eric; Chancibaut, Katia

2015-04-01

The forecast of pavement surface temperature is very specific in the context of urban winter maintenance. to manage snow plowing and salting of roads. Such forecast mainly relies on numerical models based on a description of the energy balance between the atmosphere, the buildings and the pavement, with a canyon configuration. Nevertheless, there is a specific need in the physical description and the numerical implementation of the traffic in the energy flux balance. This traffic was originally considered as a constant. Many changes were performed in a numerical model to describe as accurately as possible the traffic effects on this urban energy balance, such as tires friction, pavement-air exchange coefficient, and infrared flux neat balance. Some experiments based on infrared thermography and radiometry were then conducted to quantify the effect fo traffic on urban pavement surface. Based on meteorological data, corresponding pavement temperature forecast were calculated and were compared with fiels measurements. Results indicated a good agreement between the forecast from the numerical model based on this energy balance approach. A complementary forecast approach based on principal component analysis (PCA) and partial least-square regression (PLS) was also developed, with data from thermal mapping usng infrared radiometry. The forecast of pavement surface temperature with air temperature was obtained in the specific case of urban configurtation, and considering traffic into measurements used for the statistical analysis. A comparison between results from the numerical model based on energy balance, and PCA/PLS was then conducted, indicating the advantages and limits of each approach.

Assessment of technical condition of concrete pavement by the example of district road

Science.gov (United States)

Linek, M.; Nita, P.; Żebrowski, W.; Wolka, P.

2018-05-01

The article presents the comprehensive assessment of concrete pavement condition. Analyses included the district road located in the swietokrzyskie province, used for 11 years. Comparative analyses were conducted twice. The first analysis was carried out after 9 years of pavement operation, in 2015. In order to assess the extent of pavement degradation, the tests were repeated in 2017. Within the scope of field research, the traffic intensity within the analysed road section was determined. Visual assessment of pavement condition was conducted, according to the guidelines included in SOSN-B. Visual assessment can be extended by ground-penetrating radar measurements which allow to provide comprehensive assessment of the occurred structure changes within its entire thickness and length. The assessment included also performance parameters, i.e. pavement regularity, surface roughness and texture. Extension of test results by the assessment of changes in internal structure of concrete composite and structure observations by means of Scanning Electron Microscope allow for the assessment of parameters of internal structure of hardened concrete. Supplementing the observations of internal structure by means of computed tomography scan provides comprehensive information of possible discontinuities and composite structure. According to the analysis of the obtained results, conclusions concerning the analysed pavement condition were reached. It was determined that the pavement is distinguished by high performance parameters, its condition is good and it does not require any repairs. Maintenance treatment was suggested in order to extend the period of proper operation of the analysed pavement.

Utilization of crushed clay brick in concrete industry

Directory of Open Access Journals (Sweden)

Ali A. Aliabdo

2014-03-01

Full Text Available A comprehensive experimental program regarding the use of recycled aggregates produced from demolition of brick buildings is presented. The brick wastes were crushed, sorted and classified into coarse and fine aggregates as well as powder (CBP. The first phase of the research focuses on the effect of incorporating recycled aggregates on physico-mechanical properties of paste, mortar and concrete. Non-traditional tests including X-ray diffraction (XRD, thermo-gravimetric analysis (TGA and micro-structural analysis (MSA were performed. The second phase of the program explores the effect of using recycled aggregates on properties of concrete masonry units. A total of 44 mixtures were utilized throughout the program. Results show cement paste when modified with 25% CBP achieves smaller pore size and lower weight loss under high temperature than reference paste. Furthermore, the use of recycled aggregates reduces the overall unit weight of concrete masonry units. Actually, modified concrete masonry units incorporating recycled aggregates achieve lower unit weight, higher thermal resistance and absorption rate than reference units. Although considerable strength reduction is noticeable by substitution, compressive strength levels meet the Egyptian specifications limitations. Critical replacement ratios are suggested to produce load bearing-concrete masonry units. Based on experimental evidences, it can be stated that the use of recycled aggregate and dust made of clay bricks is promising in many applications where the thermal resistance, cost and environmental aspects are imperative.

Interim revision of the South African Mechanistic-Empirical pavement design method for flexible pavements

CSIR Research Space (South Africa)

Theyse, HL

2011-09-01

Full Text Available Pavement design methods, in combination with network level management systems must enable road authorities to develop reliable long-term financial plans based on the estimated structural capacity of the road network. Inaccurate design models...

Nondestructive pavement evaluation using finite element analysis based soft computing models.

Science.gov (United States)

2009-09-15

Evaluating structural condition of existing, in-service pavements constitutes annually a major part of the : maintenance and rehabilitation activities undertaken by State Highway Agencies (SHAs). Accurate : estimation of pavement geometry and layer m...

The Heat Transfer Coefficient of Recycled Concrete Bricks Combination with EPS Insulation Board Wall

Directory of Open Access Journals (Sweden)

Jianhua Li

2015-01-01

Full Text Available Four tectonic forms samples were conducted to test their heat transfer coefficients. By analyzing and comparing the test values and theoretical values of the heat transfer coefficient, a corrected-value calculation method for determining the heat transfer coefficient was proposed; the proposed method was proved to be reasonably correct. The results indicated that the recycled concrete brick wall heat transfer coefficient is higher than that of the clay brick wall, the heat transfer coefficient of recycled concrete brick wall could be effectively reduced when combined with the EPS insulation board, and the sandwich insulation type was better than that of external thermal insulation type.

Estimating safety effects of pavement management factors utilizing Bayesian random effect models.

Science.gov (United States)

Jiang, Ximiao; Huang, Baoshan; Zaretzki, Russell L; Richards, Stephen; Yan, Xuedong

2013-01-01

Previous studies of pavement management factors that relate to the occurrence of traffic-related crashes are rare. Traditional research has mostly employed summary statistics of bidirectional pavement quality measurements in extended longitudinal road segments over a long time period, which may cause a loss of important information and result in biased parameter estimates. The research presented in this article focuses on crash risk of roadways with overall fair to good pavement quality. Real-time and location-specific data were employed to estimate the effects of pavement management factors on the occurrence of crashes. This research is based on the crash data and corresponding pavement quality data for the Tennessee state route highways from 2004 to 2009. The potential temporal and spatial correlations among observations caused by unobserved factors were considered. Overall 6 models were built accounting for no correlation, temporal correlation only, and both the temporal and spatial correlations. These models included Poisson, negative binomial (NB), one random effect Poisson and negative binomial (OREP, ORENB), and two random effect Poisson and negative binomial (TREP, TRENB) models. The Bayesian method was employed to construct these models. The inference is based on the posterior distribution from the Markov chain Monte Carlo (MCMC) simulation. These models were compared using the deviance information criterion. Analysis of the posterior distribution of parameter coefficients indicates that the pavement management factors indexed by Present Serviceability Index (PSI) and Pavement Distress Index (PDI) had significant impacts on the occurrence of crashes, whereas the variable rutting depth was not significant. Among other factors, lane width, median width, type of terrain, and posted speed limit were significant in affecting crash frequency. The findings of this study indicate that a reduction in pavement roughness would reduce the likelihood of traffic

Evaluation of the MIT-Scan-T2 for non-destructive PCC pavement thickness determination.

Science.gov (United States)

2008-07-01

The MIT-Scan-T2 device is marketed as a non-destructive way to determine pavement thickness on both : HMA and PCC pavements. PCC pavement thickness determination is an important incentivedisincentive : measurement for the Iowa DOT and contractors. Th...

Coal-tar based pavement sealant toxicity to freshwater macroinvertebrates

International Nuclear Information System (INIS)

Bryer, Pamela J.; Scoggins, Mateo; McClintock, Nancy L.

2010-01-01

Non-point-source pollution is a major source of ecological impairment in urban stream systems. Recent work suggests that coal-tar pavement sealants, used extensively to protect parking areas, may be contributing a large portion of the polycyclic aromatic hydrocarbon (PAH) loading seen in urban stream sediments. The hypothesis that dried coal-tar pavement sealant flake could alter the macroinvertebrate communities native to streams in Austin, TX was tested using a controlled outdoor laboratory type approach. The treatment groups were: control, low, medium, and high with total PAH concentrations (TPAH = sum of 16 EPA priority pollutant PAHs) of 0.1, 7.5, 18.4, and 300 mg/kg respectively. The low, medium, and high treatments were created via the addition of dried coal-tar pavement sealant to a sterile soil. At the start of the 24-day exposure, sediment from a minimally impacted local reference site containing a community of live sediment-dwelling benthic macroinvertebrates was added to each replicate. An exposure-dependent response was found for several stream health measures and for several individual taxa. There were community differences in abundance (P = 0.0004) and richness (P < 0.0001) between treatments in addition to specific taxa responses, displaying a clear negative relationship with the amount of coal-tar sealant flake. These results support the hypothesis that coal-tar pavement sealants contain bioavailable PAHs that may harm aquatic environments. - Coal-tar pavement sealants degrade stream invertebrate communities.

Motorist actions at a crosswalk with an in-pavement flashing light system.

Science.gov (United States)

Karkee, Ganesh J; Nambisan, Shashi S; Pulugurtha, Srinivas S

2010-12-01

An in-pavement flashing light system is used at crosswalks to alert motorists and pedestrians of possible conflicts and to influence their behavior to enhance safety. The relative behaviors of the drivers and the pedestrians affect safety. An evaluation of motorist behavior at a pedestrian crosswalk with an in-pavement flashing light system is presented in this manuscript. Field observations provide the basis to evaluate motorist behavior at a crosswalk with an in-pavement flashing light system. Outcomes of pedestrian and motorists actions were observed to quantify measures of effectiveness (MOEs) such as yielding behavior of motorists, vehicle speeds, and yielding distance from the crosswalk. A before-and-after study design was used. The before condition was prior to the activation of the in-pavement flashing light system and the after condition was after the activation of the in-pavement flashing light system. The study was conducted on a relatively low-volume roadway located in the Henderson, Nevada. The significance of the differences in the MOEs between the 2 study periods was evaluated using statistical analysis tools such as a one-tailed test for proportions and the Welch-Satterthwaite t-test. The results show that the installation of the in-pavement flashing light system increased the yielding behavior of motorists significantly (P pavement flashing light system is seen to be effective to improve motorists' yielding behavior and the speeds of vehicles were also observed to decrease in the presence of pedestrians.

A comprehensive study of the energy absorption and exposure buildup factors of different bricks for gamma-rays shielding

Directory of Open Access Journals (Sweden)

M.I. Sayyed

Full Text Available The present investigation has been performed on different bricks for the purpose of gamma-ray shielding. The values of the mass attenuation coefficient (µ/ρ, energy absorption buildup factor (EABF and exposure buildup factor (EBF were determined and utilized to assess the shielding effectiveness of the bricks under investigation. The mass attenuation coefficients of the selected bricks were calculated theoretically using WinXcom program and compared with MCNPX code. Good agreement between WinXcom and MCNPX results was observed. Furthermore, the EABF and EBF have been discussed as functions of the incident photon energy and penetration depth. It has been found that the EABF and EBF values are very large in the intermediate energy region. The steel slag showed good shielding properties, consequently, this brick is eco-friendly and feasible compared with other types of bricks used for construction. The results in this work should be useful in the construction of effectual shielding against hazardous gamma-rays. Keywords: Brick, Mass attenuation coefficient, Buildup factor, G-P fitting, Radiation shielding

Integration of pavement cracking prediction model with asset management and vehicle-infrastructure interaction models.

Science.gov (United States)

2015-01-01

Not long after the construction of a pavement or a new pavement surface, various : forms of deterioration begin to accumulate due to the harsh effects of traffic loading : combined with weathering action. In a recent NEXTRANS project, a pavement crac...

Effects of water on mortar-brick bond

NARCIS (Netherlands)

Groot, C.J.W.P.