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Sample records for viaduct aashto precast

  1. Use of precast concrete deck panels : summary of research panel types I, II, and III.

    Science.gov (United States)

    1999-08-01

    The objective of this research was to investigate the feasibility of using precast concrete deck panels in place of traditional formwork for AASHTO girder type bridges. The precast deck panels span between girders, support the weight of a topping sla...

  2. Structural Precast Concrete Handbook

    DEFF Research Database (Denmark)

    Kjærbye, Per Oluf H

    Structural concept for precast concrete systems. Design og precast reinforced concrete components. Design of precast concrete connections. Illustrations on design of precast concrete buildings. Precast concrete assembly.......Structural concept for precast concrete systems. Design og precast reinforced concrete components. Design of precast concrete connections. Illustrations on design of precast concrete buildings. Precast concrete assembly....

  3. Correlation of shear design between AASHTO LRFD bridge design specifications and AASHTO Guide Specifications for the LRFD Seismic Bridge Design.

    Science.gov (United States)

    2017-01-05

    This report presents the analytical study of the shear capacity of reinforced concrete columns using both the AASHTO LRFD Bridge Design Specifications and the AASHTO Guide Specifications for the LRFD Seismic Bridge Design. The study investigates vari...

  4. Numerical Limit Analysis of Precast Concrete Structures

    DEFF Research Database (Denmark)

    Herfelt, Morten Andersen

    . The strength and efficiency of the presented framework are demonstrated by two real size examples, a two-dimensional precast shear wall and a three-dimensional precast concrete stairwell. The analysis shows that the framework is capable of modelling complex precast concrete structures efficiently. Moreover......Precast concrete elements are widely used in the construction industry as they provide a number of advantages over the conventional in-situ cast concrete structures. Joints cast on the construction site are needed to connect the precast elements, which poses several challenges. Moreover....... The scope is to be able to model entire precast concrete structures while accounting for the local behaviour of the joints. The in-situ cast joints are crucial to the capacity of precast concrete structures, however, the behaviour of joints is in practice assessed by simple, empirical design formulas...

  5. UDOT calibration of AASHTO's new prestress loss design equations.

    Science.gov (United States)

    2009-07-01

    In the next edition of the AASHTO LRFD Bridge Design Specifications the procedure to calculate prestress losses will change dramatically. The new equations are empirically based on high performance concrete from four states (Nebraska, New Hampshire, ...

  6. UDOT's calibration of AASHTO's new prestress loss design equations.

    Science.gov (United States)

    2009-07-01

    In the next edition of the AASHTO LRFD Bridge Design Specifications the procedure to calculate prestress losses will change dramatically. The new equations are empirically based on high performance concrete from four states (Nebraska, New Hampshire, ...

  7. AASHTO mechanistic-empirical pavement design guide parametric study.

    Science.gov (United States)

    2012-03-01

    This study focuses on assessing the robustness of the AASHTO Mechanistic-Empirical Pavement Design Guide (MEPDG v 1.1) for rigid pavement : design projects in Wisconsin. The primary tasks conducted in this study included performing sensitivity analys...

  8. MONITORING OF DISPLACEMENT ABUTMENTS OF MOTORWAY VIADUCT

    Directory of Open Access Journals (Sweden)

    Krzysztof TROJNAR

    Full Text Available The aim of the paper is controlling the behavior of the bridge supports of the motorway viaduct WA-164 on strengthened subsoil using soil-cement columns made in DSM technology. Monitoring of the construction was carried out for a period of 16 months by measuring the settlement and rotation of the structure. The settlements were measured by means of the geodesic precision leveling method. Changes in the rotation of the supports were recorded using a inclinometer sensors installed on the walls of the abutments. For mapping of the construction work, numerical models of span and abutments were performed. The abutment was modeled in computer program SOFiSTiK. The stiffness of subsoil was calibrated with regard to the measured settlement of the abutment on DSM columns. The results of field measurements shows that after backfilling the abutments, it leaned in the embankments direction. This is also confirmed by numerical analysis. Monitoring conducted in 2014 showed that settlement is stabilized, and the measured values are safe and lower than the SLS limit stage. Numerical modeling along with geotechnical and geodetic monitoring has enabled a better understanding of the behavior of the bridge foundation on strengthened subsoil and verify the calculation assumptions taken at the stage of design calculations.

  9. Precast concrete barrier crash testing : final report.

    Science.gov (United States)

    2001-12-01

    The objectives of this project were to crash test the Oregon Standard (32-inch) F-shape precast concrete barrier and the Oregon Tall (42-inch) F-shape precast concrete barrier against the new NCHRP Report 350 standards, to ensure compliance of these ...

  10. EXPERIMENT AL AND THEORETICAL STUDY OF PRECAST ...

    African Journals Online (AJOL)

    EXPERIMENT AL AND THEORETICAL STUDY OF PRECAST BEAM-SLAB. CONSTRUCTION. Girma Zerayohannes and Adil Zekaria. Department of Civil Engineering. Addis Ababa University. ABSTRACT. The use of partially precast beam elements ivith shear connectors in slab construction relieves the requirement of ...

  11. Towards slender, innovative concrete structures for replacement of existing viaducts

    NARCIS (Netherlands)

    Reitsema, A.D.; Lukovic, M.; Hordijk, D.A.; Beushausen, H.

    2016-01-01

    A majority of the bridges and viaducts in the Netherlands were built in the sixties and seventies of the last century and many of them will need to be replaced in the near future due to technical or functional reasons. This is a replacement issue, faced by many countries worldwide. But what about

  12. Proof load testing of the viaduct De Beek

    NARCIS (Netherlands)

    Lantsoght, E.O.L.; Koekkoek, R.T.; Yang, Y.; van der Veen, C.; de Boer, A.; Hordijk, D.A.

    2017-01-01

    Proof load testing can be a suitable method to show that a bridge can carry the required loads from the code without distress. This paper addresses the preparation, execution, and analysis of a proof load test on a four-span reinforced concrete solid slab bridge, viaduct de Beek. The bridge has one

  13. Gates Precast Concrete User Project Phase 1

    Energy Technology Data Exchange (ETDEWEB)

    Love, Lonnie J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Post, Brian K. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Roschli, Alex C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Chesser, Phillip C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-09-01

    The primary objective of the project was to demonstrate the viability of using carbon fiber reinforced ABS plastic and the Big Area Additive Manufacturing (BAAM) technology to rapidly manufacture molds for the precast concrete industry.

  14. Performance evaluation of precast prestressed concrete pavement.

    Science.gov (United States)

    2007-11-01

    This report describes in detail an experimental investigation of an innovative precast prestressed concrete pavement (PPCP) system used to rehabilitate a 1,000 ft. section of interstate highway located on the northbound lanes of I-57 near Charleston,...

  15. Precast concrete elements for accelerated bridge construction : laboratory testing of precast substructure components, Boone County bridge.

    Science.gov (United States)

    2009-01-01

    Vol. 1-1: In July 2006, construction began on an accelerated bridge project in Boone County, Iowa that was composed of precast substructure : elements and an innovative, precast deck panel system. The superstructure system consisted of full-depth dec...

  16. Lightweight Aggregate Concrete. The materials in the precast elements

    DEFF Research Database (Denmark)

    Goltermann, Per; Larsen, Henning; Ingholt, N.U.

    1996-01-01

    The precast lightweight aggregate concrete (LAC) elements are used extensively in Denmark, where the use of precast elements domonates the building structures. Similar elements are used in other parts of Nothern Europe, which have lead to development of an European standard for precast LAC elements...

  17. 29 CFR 1926.704 - Requirements for precast concrete.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Requirements for precast concrete. 1926.704 Section 1926..., DEPARTMENT OF LABOR (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Concrete and Masonry Construction § 1926.704 Requirements for precast concrete. (a) Precast concrete wall units, structural framing...

  18. LIGHTWEIGHT SLAB CAST OVER PRECAST JOISTS

    Directory of Open Access Journals (Sweden)

    Koyankin Aleksandr Aleksandrovich

    2017-07-01

    Full Text Available Precast-monolithic house-building in domestic and world practice is a significant part in the mass construction. We propose a relatively large number of designs of precast-monolithic buildings, as well as its individual elements. Despite this, we cannot say that found the most effective constructive solutions able to satisfy the requirements of consumers (future residents and builders. On this basis, we developed quite effective, from the point of view of construction and further operation, a constructive solution of light weight precast-monolithic overlap. Some features offered are overlapping: smaller mass, compared with beams of heavy concrete; increased heat and sound insulation properties; optimal use of the structural properties of heavy and light precast monolithic concrete and longitudinal reinforcement, depending on the stage of construction. The author has carried out in this article the results of numerical studies the proposed design of precast-monolithic overlap, confirming its compliance with the requirements of 1st and 2nd group of limit States.

  19. 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

  20. Software for AASHTO LRFD combined shear and torsion computations using modified compression field theory and 3D truss analogy.

    Science.gov (United States)

    2011-10-01

    The shear provisions of the AASHTO LRFD Bridge Design Specifications (2008), as well as the simplified : AASHTO procedure for prestressed and non-prestressed reinforced concrete members were investigated and compared : to their equivalent ACI 318-08 ...

  1. Reflective Cracking between Precast Prestressed Box Girders

    Science.gov (United States)

    2017-06-30

    The adjacent precast prestressed concrete box-beam bridge is the bridge of choice for short and short-to-medium span bridges. This choice is because of the ease of construction, favorable span-to-depth ratios, aesthetic appeal, and high torsional sti...

  2. Training Guidelines. Operatives-Precast Concrete.

    Science.gov (United States)

    Ceramics, Glass, and Mineral Products Industry Training Board, Harrow (England).

    This manual is intended to provide guidelines for firms in the precast concrete industry in planning their training programs particularly with reference to new entrants into the industry. Details for preparing training syllabuses for various job specifications are given--mould makers in timber, steel, and glass fiber; makers; finishers; site…

  3. Seismic Performance of Precast Polystyrene RC Walls

    Directory of Open Access Journals (Sweden)

    Wibowo Ari

    2017-01-01

    Full Text Available Precast concrete structure such as precast wall is a concept that is growing rapidly these days. However, the earthquake resistance is believed to be one of its drawbacks. Additionally, the large weight of solid elements also increase the building weight significantly which consequently increase the earthquake base shear force as well. Therefore, investigation on the seismic performance of precast concrete wall has been carried out. Three RC wall specimens using wire mesh reinforcement and EPS (Extended Polystyrene System panel have been tested. This wall was designed as a structural wall that was capable in sustaining lateral loads (in-plane yet were lightweight to reduce the total weight of the building. Parameter observed was the ratio of height to width (aspect ratio of wall of 1.0, 1.5 and 2.0 respectively with the aim to study the behaviour of brittle to ductile transition of the wall. Incremental static load tests were conducted until reaching peak load and then followed by displacement control until failure. Several data were measured at every stage of loading comprising lateral load-displacement behaviour, ultimate strength and collapse mechanism. The outcomes showed that precast concrete walls with a steel wire and EPS panel filler provided considerably good resistance against lateral load.

  4. Development of high performance precast/prestressed bridge girders

    Science.gov (United States)

    Akhnoukh, Amin K.

    Demand continues to increase for bridges with long spans and shallow depths. Due to safety concerns, four-span overpasses are being replaced with two span overpasses to avoid placement of piers near the highway shoulders. In the meantime, the bridge profile is restricted due to existing businesses nearby. Thus, nearly the same superstructure depth must be used for double the span length. This dissertation focuses on topics aiming at providing precast prestressed concrete girders with the shallowest possible depth for a given span. It forms parts of larger projects conducted by the University of Nebraska for the Nebraska Department of Roads and for the Wire Reinforcement Institute. Specifically, the following issues were researched: (1) Use of 0.7 in. diameter Grade 270 ksi strands for pretensioning of precast concrete girders at a strand spacing of 2 inches by 2 inches. This arrangement gives nearly 190 percent of the prestressing with 0.5 in. diameter strands and nearly 135 percent with 0.6 in. strands. The research focuses on the required confinement steel to allow determination of transfer and development lengths according to current procedures in the AASHTO LRFD Bridge Design Specifications for smaller strands. (2) Develop a self consolidating concrete (SCC) mix, using Nebraska aggregates that will allow for a specified design strength at service of 15 ksi and a minimum strength at one day of 10 ksi, representing the demand at the time of release of the prestress to the concrete member. Prior to this study, standard concrete strength prevailing in Nebraska has been 8 ksi at service and 6.5 ksi at release. It was the goal of the research to keep the cost of materials as low as possible but not exceeding 250 per cubic yard, compared to the proprietary mixes that cost approximately four times this amount. (3) Use of 80 ksi welded wire reinforcement (WWR) as the auxiliary reinforcement for shear, web end splitting and flange confinement. This would result in higher

  5. Assessment of structural reliability of precast concrete buildings

    Directory of Open Access Journals (Sweden)

    Koyankin Alexandr

    2018-01-01

    Full Text Available Precast housing construction is currently being under rapid development, however, reliability of building structures made from precast reinforced concrete cannot be assessed rationally due to insufficient research data on that subject. In this regard, experimental and numerical studies were conducted to assess structural reliability of precast buildings as described in the given paper. Experimental studies of full-scale and model samples were conducted; numerical studies were held based on finite element models using “Lira” software. The objects under study included fragment of flooring of a building under construction, full-size fragment of flooring, full-scale models of precast cross-beams-to-columns joints and joints between hollow-core floor slabs and precast and cast-in-place cross-beams. Conducted research enabled to perform an objective assessment of structural reliability of precast buildings.

  6. Precast/Prestressed Concrete Experiments - Series 1 (Volume 1)

    Science.gov (United States)

    2008-11-01

    AFRL-RX-TY-TR-2008-4616 PRECAST/ PRESTRESSED CONCRETE EXPERIMENTS – SERIES 1 (VOLUME I) Clay J. Naito Associate Professor Department of...specific retrofit. To illustrate this concept, the blast resistances of non-load bearing precast, prestressed concrete sandwich wall panels (WP) are...resistances of non-load bearing precast, prestressed concrete sandwich wall panels (WP) are examined. These components are used extensively in

  7. A Study on Hybrid Precast walls

    Science.gov (United States)

    Rohith, S.; Chidambaram, C. R.; Karthikeyan, K.; Santhi, M. Helen

    2017-07-01

    This study proposes an innovative wall system so called as hybrid precast walls (HW). HW uses both mild steel and high strength steel angles for flexural resistance across horizontal joint. High strength steel plates are used for steel angles connection at the horizontal precast joint and also at places where angles cross which assist for the re-centering property of the HW walls. HW is designed with mild steel to yield both tension and compression whereas the steel angles provide re-centering capability and thereby reducing lateral displacements. Efficiency of the structure depends upon the performance of both reinforcements accordingly to what it is meant to be. This paper presents the seismic performance studies of HW under gradually applied lateral static load. Experimental studies were carried out which account for steel yielding, concrete cracking and crushing.

  8. Natural frequencies of a flat viaduct road part simply supported on ...

    Indian Academy of Sciences (India)

    related environmental pollution. In this study, bending vibrations of rectangular plate viaduct roads, which are supported by six fixed elements of rectangular cross-sectional elements are con- sidered. Natural frequencies are obtained using the ...

  9. Evaluation of structural systems in precast concrete buildings by ...

    African Journals Online (AJOL)

    In general, the precast concrete is the type of concrete that constructing, casting and curing in the standard factory conditions with high quality and then it will be transported with proper equipments and then it will be installed in the final position. In fact, the precast concrete buildings are the combined of several types of ...

  10. Assessment of current AASHTO LRFD methods for static pile capacity analysis in Rhode Island soils.

    Science.gov (United States)

    2013-07-01

    This report presents an assessment of current AASHTO LRFD methods for static pile capacity analysis in Rhode : Island soils. Current static capacity methods and associated resistance factors are based on pile load test data in sands : and clays. Some...

  11. Numerical Limit Analysis of Precast Concrete Structures

    DEFF Research Database (Denmark)

    Herfelt, Morten Andersen; Poulsen, Peter Noe; Hoang, Linh Cao

    2016-01-01

    Design and analysis of precast concrete structures in the ultimate limit state is largely done by simple analytical calculations and linear elastic finite element analysis, which necessarily leads to suboptimal designs. Numerical limit analysis provides a framework well suited for this task...... optimisation as well as material optimisation is given and a four-storey shear wall is analysed using load optimisation. The analysis yields a capacity more than three times larger than the design load for the critical load case, and the collapse mode and stress distribution are analysed. Finally, numerical...

  12. Retaining Walls Made of Precast Cylindrical Valuts

    Directory of Open Access Journals (Sweden)

    N. Ungureanu

    2005-01-01

    Full Text Available Retaining walls are large category of engineering structures of multiple uses, having an essential safety ensuring role. The structural systems are varied because the situations and requirements derived from both site conditions and other criteria are varied. The paper enlarges upon retaining walls systems that use an outstanding amount of precast units and multiple cylindrical vault type structural systems supported by abutments [1], [2]. The paper proposes extending the structural system to retaining walls and develops certain specific issues. Some considerations regarding structural design are made.

  13. Re-evaluation of the AASHTO-flexible pavement design equation with neural network modeling.

    Science.gov (United States)

    Tiğdemir, Mesut

    2014-01-01

    Here we establish that equivalent single-axle loads values can be estimated using artificial neural networks without the complex design equality of American Association of State Highway and Transportation Officials (AASHTO). More importantly, we find that the neural network model gives the coefficients to be able to obtain the actual load values using the AASHTO design values. Thus, those design traffic values that might result in deterioration can be better calculated using the neural networks model than with the AASHTO design equation. The artificial neural network method is used for this purpose. The existing AASHTO flexible pavement design equation does not currently predict the pavement performance of the strategic highway research program (Long Term Pavement Performance studies) test sections very accurately, and typically over-estimates the number of equivalent single axle loads needed to cause a measured loss of the present serviceability index. Here we aimed to demonstrate that the proposed neural network model can more accurately represent the loads values data, compared against the performance of the AASHTO formula. It is concluded that the neural network may be an appropriate tool for the development of databased-nonparametric models of pavement performance.

  14. Re-evaluation of the AASHTO-flexible pavement design equation with neural network modeling.

    Directory of Open Access Journals (Sweden)

    Mesut Tiğdemir

    Full Text Available Here we establish that equivalent single-axle loads values can be estimated using artificial neural networks without the complex design equality of American Association of State Highway and Transportation Officials (AASHTO. More importantly, we find that the neural network model gives the coefficients to be able to obtain the actual load values using the AASHTO design values. Thus, those design traffic values that might result in deterioration can be better calculated using the neural networks model than with the AASHTO design equation. The artificial neural network method is used for this purpose. The existing AASHTO flexible pavement design equation does not currently predict the pavement performance of the strategic highway research program (Long Term Pavement Performance studies test sections very accurately, and typically over-estimates the number of equivalent single axle loads needed to cause a measured loss of the present serviceability index. Here we aimed to demonstrate that the proposed neural network model can more accurately represent the loads values data, compared against the performance of the AASHTO formula. It is concluded that the neural network may be an appropriate tool for the development of databased-nonparametric models of pavement performance.

  15. Effect of portland cement (current ASTM C150/AASHTO M85) with limestone and process addition (ASTM C465/AASHTO M327) on the performance of concrete for pavement and bridge decks.

    Science.gov (United States)

    2014-02-01

    The Illinois Department of Transportation (IDOT) is making several changes to concrete mix designs, using revisions to : cement specification ASTM C150/AASHTO M85 and ASTM C465/AASHTO M327. These proposed revisions will enable the : use of more susta...

  16. Evaluation of precast concrete slabs using a heavy vehicle simulator

    CSIR Research Space (South Africa)

    Kohler, E

    2008-10-01

    Full Text Available Precast slabs are considered an attractive pavement option for rehabilitation or reconstruction cases where traffic closures of less than eight hours are required. Benefits include long life expectancy of concrete cast in factory...

  17. Implementation of precast concrete deck system NUDECK (2nd generation).

    Science.gov (United States)

    2013-12-01

    The first generation of precast concrete deck system, NUDECK, developed by the University of NebraskaLincoln (UNL) for Nebraska Department of Roads (NDOR), was implemented on the Skyline Bridge, : Omaha, NE in 2004. The project was highly successful ...

  18. Reflective Cracking between Precast Prestressed Box Girders : Research Brief

    Science.gov (United States)

    2017-08-01

    Ease of construction, favorable span-to-depth ratios, aesthetic appeal and high torsional stiffness make adjacent precast prestressed concrete box-beams a popular option for short-to-medium span bridges. However, persisting durability and performance...

  19. Rapid bridge construction technology : precast elements for substructures.

    Science.gov (United States)

    2011-06-01

    The goal of this research was to propose an alternate system of precast bridge substructures which can : substitute for conventional cast in place systems in Wisconsin to achieve accelerated construction. : Three types of abutment modules (hollow wal...

  20. Spalling solution of precast-prestressed bridge deck panels.

    Science.gov (United States)

    2010-10-01

    This research has examined spalling of several partial-depth precast prestressed concrete (PPC) bridge decks. It was recently obser : that some bridges with this panel system in the MoDOT inventory have experienced rusting of embedded steel reinforce...

  1. Evaluation of continuity detail for precast prestressed girders.

    Science.gov (United States)

    2011-08-01

    The construction of highway bridges using precast prestressed concrete (PSC) girders is considered one of the most : economical construction alternatives because of the advantages they offer (e.g. reducing formwork and rapid construction). : Construc...

  2. Evaluation of continuity detail for precast prestressed girders : tech summary.

    Science.gov (United States)

    2011-08-01

    Building multi-simple span bridges using precast prestressed concrete girders is an easy construction. However, the existence of : expansion joints often leads to a host of problems in their vicinity due to drainage leaks. Furthermore, debris accumul...

  3. Investigation of post-earthquake displacements in viaducts using Geodetic and Finite Element Methods

    Directory of Open Access Journals (Sweden)

    D. Güney

    2010-12-01

    Full Text Available This paper presents the results of research into the post-earthquake displacements of the partially constructed road viaducts in Bolu, Turkey after the Izmit/Kocaeli, (Mw = 7.4, and Düzce (Mw = 7.1 earthquakes on 17 August and 12 November 1999, respectively. The investigations on the viaducts were carried out using both Geodetic and Finite Element Methods (FEM. Firstly, all the geodetic network stations selected for the project were checked because of the recent deformation in the area. Then, new control stations were placed between the piers of the viaducts. 28 object points were placed and measured on each pier to determine their displacements. In the second stage, the behaviours of the viaducts were modelled using the FEM, and the Düzce earthquake acceleration record was analysed to observe the response of the viaducts in a time history domain. The modelled displacement response of the viaducts was compared with the geodetic measurements in order to interpret the sensitivity of the design calculation of the engineering model. The pier displacements that were geodetically measured and calculated using FEM peak pier displacements showed an increase in the piers located closer to the surface rupture from the Izmit/Kocaeli and Düzce earthquakes. The agreement between the observed and modelled displacements decreases with the increase in the distance from the fault line. Since, near the fault trace the horizontal displacement field is discontinuous and large inelastic deformation is expected, the behaviour of the part of the structure located near the fault line cannot be easily reproduced by FEM simulations. This is because the applied model loads derived from the source acceleration spectra cannot be included in the localized finite deformation effects. In order to obtain an improved engineering analysis, it is necessary to utilise more parameters in the numerical analysis.

  4. 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.

  5. Accelerated slab replacement using temporary precast panels and self-consolidating concrete : [summary].

    Science.gov (United States)

    2016-06-01

    Researchers at Florida State University demonstrated the feasibility of using precast reinforced concrete panels to temporarily fill slab removal pits. The precast slabs can be driven on so traffic lanes can be open during the day, and new slab casti...

  6. Natural frequencies of a flat viaduct road part simply supported on ...

    Indian Academy of Sciences (India)

    In this study, bending vibrations of rectangular plate viaduct roads, which are supported by six fixed elements of rectangular cross-sectional elements are considered. ... Yildiz Technical University, Mechanical Engineering Faculty, Mechanical Engineering Department, 34349, Beşiktaş, İstanbul, Turkey; Yildiz Technical ...

  7. Precast Slab Literature Review Report: Repair of Rigid Airfield Pavements Using Precast Concrete Panels - A State-of-the-Art Review

    Science.gov (United States)

    2010-06-01

    accommodate stresses imposed during handling and transportation of precast panels. 4 Prestressed concrete contains prestressing tendons (generally high...runway), or a highway. A highway example includes the construction of 305 m (1000 ft) long and 11.5 m (38 ft) wide precast prestressed concrete pavement...precast prestressed concrete panels is an evolving specialized construction technology. The development of this technology is supported by the

  8. Rail expansion devices monitored by FBG sensors on an urban railway viaduct

    Science.gov (United States)

    Li, Weilai; Pang, Jin; Lu, Xiaoshan; Liu, Jie

    2014-06-01

    The fiber Bragg grating (FBG) sensing technology was used to monitor the situation of a crevice of the continuous beam joint and rails near rail expansion devices on a viaduct of the urban railway. The monitoring items consisted of the rail temperature, rail displacement, viaduct beam displacement, and strain of sliding rail in the rail expansion device section. The strain sensor was a prefabricate FBG strain gauge, the displacement sensor with different scales used an FBG stress ring, and the FBG of the temperature sensor was pre-drawn and fixed in a metal tube. Compensation sensors were used to balance environmental temperature changes. All FBGs were suspended adhered, therefore the chirped phenomenon of the FBG reflection peak was avoided, and the measurement accuracy was improved. The monitoring results matched to the manual test and theoretical estimation.

  9. Safe, High-Performance, Sustainable Precast School Design

    Science.gov (United States)

    Finsen, Peter I.

    2011-01-01

    School design utilizing integrated architectural and structural precast and prestressed concrete components has gained greater acceptance recently for numerous reasons, including increasingly sophisticated owners and improved learning environments based on material benefits such as: sustainability, energy efficiency, indoor air quality, storm…

  10. A flexible mold for double curved precast concrete elements

    NARCIS (Netherlands)

    Schipper, H.R.; Vambersky, J.N.J.A.

    2010-01-01

    The manufacturing of double curved precast concrete elements is still expensive, due to the high costs and limited possibilities for repetitive use of the molds or formwork. The goal of a PhD project recently initiated at TU Delft is to develop a production method that overcomes these difficulties

  11. Experimental and theoretical study of precast beam-slab construction

    African Journals Online (AJOL)

    The use of partially precast beam elements with shear connectors in slab construction relieves the requirement of extensive use of soffit formwork and props and will have the advantage of faster construction. It also reduces adverse effects associated deforestation. Experimental and theoretical investigations were conducted ...

  12. QUALITY CONTROL IN PRECAST PRODUCTION A case study on Tunnel Segment Manufacture

    Directory of Open Access Journals (Sweden)

    Yee Weng Cheong

    2005-01-01

    Full Text Available Quality control forms an integral part of precast production. An efficient quality system is most critical in the mass production of precast components in any project. In this study, the quality control system implemented in a precast factory is discussed. The precast factory is set up for the manufacture of large quantity of tunnel segments under a contract. Processes in the precast manufacture are discussed with respect to the control procedures in the quality inspection plan. The standard tests involved, roles of inspectors and corrective actions on-site are highlighted. Critical issues pertaining to the productivity and quality of precast production are reviewed. These include the quality of staff and maintenance, which could potentially affect the efficiency of the quality system. Some considerations should also be given to improve the workflow and productivity of the plant.

  13. Analytical Assessment of the Blast Resistance of Precast, Prestressed Concrete Components (PREPRINT)

    Science.gov (United States)

    2007-04-01

    AFRL-ML-TY-TP-2007-4529 PREPRINT ANALYTICAL ASSESSMENT OF THE BLAST RESISTANCE OF PRECAST, PRESTRESSED CONCRETE COMPONENTS Nicholas...Precast, Prestressed Concrete Components Nicholas Cramsey1 and Clay Naito2 SYNOPSIS Four blast tests were performed on 30-ft (9.1-m) tall precast... prestressed concrete wall panels. Two conventional sandwich panels and a control panel were examined and shown to perform adequately under the blast

  14. Evaluation of Precast Panels for Airfield Pavement Repair. Phase 1: System Optimization and Test Section Construction

    Science.gov (United States)

    2013-06-01

    ERDC/GSL TR-13-24 130 Hachiya, Y. 2001. Rapid Repair with Precast Prestressed Concrete Slab Pavements using Compression Joint System, 7th...Research Laboratory (AFRL) reviewed the use of precast concrete panels for pavement repair applications in the U.S. and around the world. Based on this...installation for emergency and contingency portland cement concrete (PCC) pavement repairs. Seven precast concrete panels were fabricated for use in an

  15. Cost efficiency assessment of automated quality control of precast structures

    Directory of Open Access Journals (Sweden)

    Kaverzina Liudmila

    2018-01-01

    Full Text Available Relevance of the research is conditioned by the necessity to enhance the factory quality control of reinforced concrete structures based on integral assessment of their reliability. The current system of selective quality control of precast concrete structures does not provide reliability assurance of the whole lot of products. The present research aims to develop operational procedure and consider economic feasibility of automated quality control of precast RC structures. Quality control is performed each shift according to the developed software system based on probabilistic methods considering statistic variability of the controlled parameters. The critical criterion of operational integrity of structures is integral assessment of the reliability indicators. The following theoretical research methods were used in the study: probabilistic-statistical, methods of system and economic analysis. Validity of the obtained results and economic feasibility were proved by experimental studies including full-scale tests.

  16. Variety of Displacement Dependent Devices Used for Bridges and Viaducts Certified by Icecon Cert SRL

    Science.gov (United States)

    Alexandru, Carmen

    2017-12-01

    The paper is specially addressed to the seismic device manufacturer, designers and end users of these products, to explicitness the provisions of EN 15129:2009 regarding the tests shall be performed for the displacement depended devices used for bridges and viaducts. Are presented some of examples of dynamic tests carried out under the supervision of the certification body ICECON CERT SRL for the assessment and verification of constancy of performance, based on the evaluation of conformity procedures indicated in the reference document and the regulation EU no (305)/2011

  17. Evaluasi Struktural Perkerasan Kaku Menggunakan Metoda AASHTO 1993 dan Metoda AUSTROADS 2011 Studi Kasus : Jalan Cakung-Cilincing

    Directory of Open Access Journals (Sweden)

    Shinta Rahmalia Irawan

    2017-08-01

    Full Text Available Cakung-Cilincing Jakarta National Road Section has very rapid traffic load for rigid pavement. The purpose of this study are determining overlay thickness and choosing suitable method for implementation. AASHTO 1993 and AUSTROADS 2011 method are used in this study and using on Falling Weight Deflectometer (FWD data. This study shows that value of Concrete Elasticity Modulus less than 3 million, then this rigid pavement is severely damaged. Based on AASHTO 1993 Method analysis, it needs 11 cm for flexible overlay and 12 cm for rigid overlay on lane 1 with 59% remaining life and lane 2 with 53% remaining life. AUSTROADS 2011 Methods use only FWD data and for overlay thickness determination is use new pavement analysis. Analysis using AUSTROADS 2011 Methods shows that flexible overlay requirement is 24 cm and rigid overlay requirement is 18.50 cm. Comparation between these two methods shows that AASHTO 1993 Method Analysis produce less overlay thickness than AUSTROADS 2011 Methods.

  18. Lower bound element and submodel for modelling of joints between precast concrete panels

    DEFF Research Database (Denmark)

    Herfelt, Morten Andersen; Poulsen, Peter Noe; Hoang, Linh Cao

    2015-01-01

    In practice, precast concrete structures are designed using either analytical methods or linear finite element tools, and the in-situ cast joints between the precast panels are assessed using conservative empirical design formulas. This often leads to a suboptimal design, and local mechanisms...

  19. A theoretical investigation on influences of slab tracks on vertical dynamic responses of railway viaducts

    Science.gov (United States)

    Shi, Li; Cai, Yuanqiang; Wang, Peng; Sun, Honglei

    2016-07-01

    A railway viaduct model consisting of infinite spans of elastically-supported girders carrying a slab track of infinite length is established to investigate the influence of the slabs on the vertical dynamic response of the viaduct, when a moving harmonic point load or a moving sprung wheel is applied. The infinite rail, the discontinuous slabs and girders of identical span lengths are idealized as Euler-Bernoulli beams. The rail fasteners, the cushion layer beneath the slab and the elastic bearings at the girder supports are represented by discretely distributed springs of hysteretic damping. Due to the repetitive nature of the girders, the model can be divided into periodic three-beam units by the span length of the girder, and then solved analytically in the frequency domain using the property of periodic structure. Besides the first natural frequency of the girder with elastic bearings, it is found that the resonance frequency of the slab on the cushion layer has a significant influence on the dynamic response of the track and the girder. Parametric excitations due to the moving wheel periodically passing the discontinuous slabs contribute significantly to the wheel/rail interactions.

  20. Failure of landslide stabilization measures: The Sidi Rached viaduct case (Constantine, Algeria)

    Science.gov (United States)

    Guemache, Mehdi A.; Chatelain, Jean-Luc; Machane, Djamel; Benahmed, Sihem; Djadia, Leila

    2011-03-01

    The goal of this paper is to document causes of the failure of stabilization measures undertaken for stabilizing a complex landslide threatening the Sidi Rached viaduct in Constantine, Algeria. Since the first instabilities, documented in 1910 during its construction, significant disturbances have been regularly observed on its eastern part and reinforcements carried out were only temporarily effective. Observed disturbances are inherently related to the fact that the eastern abutment and the three subsequent piers are built on unstable Maastrichtian marls whereas the remainder of the viaduct rests on stable Turonian limestone. The five main factors controlling the activation of the failure process are reviewed: (1) geomorphology, (2) geology, (3) human activities, (4) climate, and (5) seismicity. Data interpretation of two inclinometer surveys carried out close to the eastern abutment shows that the unstable mass moves westward, towards the Rhumel gorges. The main slip surface is located in the Maastrichtian schistose marl, at a depth ranging from about 8 m (west) to about 30 m (east). This translational slide is associated with a settling phenomenon due to the petrophysical properties of the unstable marl.

  1. Modeling Heat and Moisture Transport in Steam-Cured Mortar: Application to Aashto Type Vi Beams.

    Science.gov (United States)

    Hernández-Bautista, E; Sandoval-Torres, S; de J Cano-Barrita, P F; Bentz, D P

    2017-10-01

    During steam curing of concrete, temperature and moisture gradients are developed, which are difficult to measure experimentally and can adversely affect the durability of concrete. In this research, a model of cement hydration coupled to moisture and heat transport was used to simulate the process of steam curing of mortars with water-to-cement (w/c) ratios by mass of 0.30 and 0.45, considering natural convection boundary conditions in mortar and concrete specimens of AASHTO Type VI beams. The primary variables of the model were moisture content, temperature, and degree of hydration. Moisture content profiles of mortar specimens (40 mm in diameter and 50 mm in height) were measured by magnetic resonance imaging. The degree of hydration was obtained by mass-based measurements of loss on ignition to 1000 °C. The results indicate that the model correctly simulates the moisture distribution and degree of hydration in mortar specimens. Application of the model to the steam curing of an AASHTO Type VI beam indicates temperature differences (between the surface and the center) higher than 20 °C during the cooling stage, and internal temperatures higher than 70 °C that may compromise the durability of the concrete.

  2. Evaluasi Struktural Perkerasan Lentur Menggunakan Metode AASHTO 1993 dan Metode Bina Marga 2013 Studi Kasus: Jalan Nasional Losari - Cirebon

    Directory of Open Access Journals (Sweden)

    Akhmad Haris Fahruddin Aji

    2015-08-01

    Full Text Available The purpose of of this research is to analyze structural flexible pavement by using Bina Marga 2013 Method and comparing with AASHTO 1993 Method, both of which are part of the non-destructive evaluation methods. Structural evaluation of flexible pavement by AASHTO 1993 Method carried out based on data deflections d1 and d6 of survey FWD (Falling Weight Deflectometer to calculate value of Resilient Modulus of subgrade (MR and Pavement Effective Modulus (EP, and then it used to determine SNeff value (Structural Number Effective, SNf value (Structural Number in the Future, and overlay thickness. While Bina Marga 2013 Method, first step of evaluation is analyzing the choice of treatment which is based on 3 trigger value, ie: Deflection Trigger, IRI Trigger, and Conditions Trigger, then continued by calculation of overlay thickness through mechanistic design approaches with graphics and General Mechanistic Procedure (GMP. Comparison of the two methods shows that overlay thickness calculation of Bina Marga 2013, is thinner than calculation of AASHTO 1993 for the same modeling assumptions, this is because Bina Marga 2013 using the analytical method with the help of CIRCLY programs so that strain stress analysis of structural as a response of pavement can be determined more accurately and represent the actual conditions on site, compared to analytical-empirical method used in AASHTO 1993 Method.

  3. Characteristics of Recycled Concrete Aggregates from Precast Slab Block Buildings

    Science.gov (United States)

    Venkrbec, Václav; Nováková, Iveta; Henková, Svatava

    2017-10-01

    Precast slab block buildings (PSBB) typically and frequently occur in Central and Eastern Europe, as well as elsewhere in the world. Some of these buildings are currently used beyond their service life capacity. The utilization of recycled materials from these buildings with regard to applying the principles of sustainable construction and using recycled materials will probably be significant in the following years. Documentation from the manufacturing processes of prefabricated blocks for precast slab block buildings is not available, and also it is difficult to declare technological discipline during the construction of these buildings. Therefore, properties of recycled concrete aggregates (RCA) produced from construction and demolition waste (C&DW) of precast slab block buildings build between 1950s to 1990s are not sufficiently known. The demolition of these buildings is very rare today, but it can be assumed an increase in demolitions of these buildings in the future. The use of RCA in new concrete requires verification/testing of the geometrical and physical properties of RCA according to the EN 12 620+A1 standard. The aim of the contribution is to present a case study of the demolition of slab block building with emphasis on RCA usage. The paper presents the results of the tests according to European standards for determining selected geometrical and physical properties of the RCA. The paper describes and evaluates tests such as determination of particle size distribution - Sieve Analysis, content of fine particles, determination of density and water absorption. The results of the properties testing of RCA are compared with the properties of natural aggregate. The general boundary conditions of RCA particular tests are presented.

  4. Beneficial Use of Carbon Dioxide in Precast Concrete Production

    Energy Technology Data Exchange (ETDEWEB)

    Shao, Yixin [McGill Univ., Montreal, QC (Canada)

    2014-06-26

    The feasibility of using carbon dioxide as feedstock in precast concrete production is studied. Carbon dioxide reacts with calcium compounds in concrete, producing solid calcium carbonates in binding matrix. Two typical precast products are examined for their capacity to store carbon dioxide during the production. They are concrete blocks and fiber-cement panels. The two products are currently mass produced and cured by steam. Carbon dioxide can be used to replace steam in curing process to accelerate early strength, improve the long-term durability and reduce energy and emission. For a reaction within a 24-hour process window, the theoretical maximum possible carbon uptake in concrete is found to be 29% based on cement mass in the product. To reach the maximum uptake, a special process is developed to promote the reaction efficiency to 60-80% in 4-hour carbon dioxide curing and improve the resistance to freeze-thaw cycling and sulfate ion attack. The process is also optimized to meet the project target of $10/tCO2 in carbon utilization. By the use of self-concentrating absorption technology, high purity CO2 can be produced at a price below $40/t. With low cost CO2 capture and utilization technologies, it is feasible to establish a network for carbon capture and utilization at the vicinity of carbon sources. If all block produces and panel producers in United States could adopt carbon dioxide process in their production in place of steam, carbon utilization in these two markets alone could consume more than 2 Mt CO2/year. This capture and utilization process can be extended to more precast products and will continue for years to come.

  5. Precast concrete unit assessment through GPR survey and FDTD modelling

    Science.gov (United States)

    Campo, Davide

    2017-04-01

    Precast concrete elements are widely used within United Kingdom house building offering ease in assembly and added values as structural integrity, sound and thermal insulation; most common concrete components include walls, beams, floors, panels, lintels, stairs, etc. The lack of respect of the manufacturer instruction during assembling, however, may induce cracking and short/long term loss of bearing capacity. GPR is a well-established not destructive technique employed in the assessment of structural elements because of real-time imaging, quickness of data collecting and ability to discriminate finest structural details. In this work, GPR has been used to investigate two different precast elements: precast reinforced concrete planks constituting the roof slab of a school and precast wood-cement blocks with insulation material pre-fitted used to build a perimeter wall of a private building. Visible cracks affected both constructions. For the assessment surveys, a GSSI 2.0 GHz GPR antenna has been used because of the high resolution required and the small size of the antenna case (155 by 90 by 105mm) enabling scanning up to 45mm from any obstruction. Finite Difference Time Domain (FDTD) numerical modelling was also performed to build a scenario of the expected GPR signal response for a preliminary real-time interpretation and to help solve uncertainties due to complex reflection patterns: simulated radargrams were built using Reflex Software v. 8.2, reproducing the same GPR pulse used for the surveys in terms of wavelet, nominal frequency, sample frequency and time window. Model geometries were derived from the design projects available both for the planks and the blocks; the electromagnetic properties of the materials (concrete, reinforcing bars, air-filled void, insulation and wooden concrete) were inferred from both values reported in literature and a preliminary interpretation of radargrams where internal layer interfaces were clearly recognizable and

  6. Self-Compacting Concrete in Precast Elements Industry

    Directory of Open Access Journals (Sweden)

    Corneliu Bob

    2005-01-01

    Full Text Available In this paper the authors present information about the Self-Compacting Concrete and experimental results regarding the use of them into precast element industry. This type of concrete does not require vibration for placing and compaction; it is able to flow under its own weight, completely filling formwork and achieving full compaction, even in the presence of congested reinforcement. The experimental programme has take into account two prestressed beams which were prefabricated and tested on a special stands. The beams of Self-Compacting Concrete with the length of 24 m were prepared at „Beton-Star” Kft, Kecsekenet, Hungary, and used at the CASCO, Satu-Mare.

  7. Advanced bridge safety initiative, task 3 : slab bridge load rating using AASHTO methodology and finite element analysis - an analysis of 20 bridges.

    Science.gov (United States)

    2011-12-01

    Current AASHTO provisions for the conventional load rating of flat slab bridges rely on the equivalent strip method : of analysis for determining live load effects, this is generally regarded as overly conservative by many professional : engineers. A...

  8. Synthesis and evaluation of lightweight concrete research relevant to the AASHTO LRFD bridge design specifications : potential revisions for definition and mechanical properties.

    Science.gov (United States)

    2012-11-01

    Much of the fundamental basis for the current lightweight concrete provisions in the AASHTO LRFD Bridge : Design Specifications is based on research of lightweight concrete (LWC) from the 1960s. The LWC that was : part of this research used tradition...

  9. Synthesis and evaluation of lightweight concrete research relevant to the AASHTO LRFD bridge design specifications : identification of articles for further evaluation and potential revision.

    Science.gov (United States)

    2012-11-01

    Much of the fundamental basis for the current lightweight concrete provisions in the AASHTO LRFD Bridge : Design Specifications is based on research of lightweight concrete (LWC) from the 1960s. The LWC that was : part of this research used tradition...

  10. Evaluating the constructability of NUDECK precast concrete deck panels for Kearney Bypass Project.

    Science.gov (United States)

    2015-02-01

    The first generation of precast concrete deck system, NUDECK, was implemented on the Skyline Bridge, : Omaha, NE in 2004. The second generation of NUDECK system was developed to further simplify the : system and improve its constructability and durab...

  11. Durability of precast prestressed concrete piles in marine environment : reinforcement corrosion and mitigation - Part 1.

    Science.gov (United States)

    2011-06-01

    Research conducted in Part 1 has verified that precast prestressed concrete piles in : Georgias marine environment are deteriorating. The concrete is subjected to sulfate and : biological attack and the prestressed and nonprestressed reinforcement...

  12. Durability of precast prestressed concrete piles in marine environment, part 2. Volume 1 : concrete.

    Science.gov (United States)

    2012-06-01

    The overall purpose of this research was to determine methods which may be applied : economically to mitigate corrosion of reinforcement in precast prestressed concrete piles in : Georgias marine environments. The research was divided into two par...

  13. Nanoporous thin film additives to improve precast concrete construction of transportation facilities.

    Science.gov (United States)

    2011-12-01

    The national transportation network contains a significant number of highway and railway bridges. This research is intended to transform the use of precast/pre-stressed materials in the transportation infrastructure. Specifically it examines how nano...

  14. Development of a precast bridge deck overhang system for the rock creek bridge.

    Science.gov (United States)

    2008-12-01

    Precast, prestressed panels are commonly used at interior beams for bridges in Texas. The use of these : panels provides ease of construction, sufficient capacity, and good economy for the construction of : bridges in Texas. Current practice for the ...

  15. Laboratory testing and finite element modeling of precast bridge deck panel transverse connections.

    Science.gov (United States)

    2010-08-06

    Precast bridge deck panels are increasingly used to reduce construction times and associated traffic delays as part of many DOTs push for accelerated bridge construction. They allow a bridge deck to be built or replaced in days instead of months. ...

  16. Abrasion-resistant concrete mix designs for precast bridge deck panels.

    Science.gov (United States)

    2010-08-01

    The report documents laboratory investigations undertaken to develop high performance concrete (HPC) for precast and pre-stressed bridge deck components that would reduce the life-cycle cost of bridges by improving the studded tire wear (abrasion) re...

  17. Improving the accuracy of camber predictions for precast pretensioned concrete beams.

    Science.gov (United States)

    2015-07-01

    The discrepancies between the designed and measured camber of precast pretensioned concrete beams (PPCBs) observed by the : Iowa DOT have created challenges in the field during bridge construction, causing construction delays and additional costs. Th...

  18. Seismic Behavior and Design of Segmental Precast Post-Tensioned Concrete Piers

    Science.gov (United States)

    2011-06-01

    Segmental precast column construction is an economic environmental friendly solution to accelerate bridge construction in the United : States. Also, concrete-filled fiber reinforced polymer tubes (CFFT) represents a potential economic solution for du...

  19. Health monitoring of precast bridge deck panels reinforced with glass fiber reinforced polymer (GFRP) bars.

    Science.gov (United States)

    2012-03-01

    The present research project investigates monitoring concrete precast panels for bridge decks that are reinforced with Glass Fiber Reinforced Polymer (GFRP) bars. Due to the lack of long term research on concrete members reinforced with GFRP bars, lo...

  20. Evaluating Louisiana new deck continuity detail for precast prestressed concrete girder bridges : research project capsule.

    Science.gov (United States)

    2014-08-01

    The goal of everyone in the transportation community is to build bridges : that are economic, easy to construct, and durable. Therefore, accelerating : bridge construction through the use of precast concrete or prefabricated : steel girders is a comm...

  1. Ensaios MSCR segundo as normas ASTM D7405-10a e AASHTO T350-14: um estudo de caso envolvendo ligantes asfálticos modificados

    Directory of Open Access Journals (Sweden)

    Matheus David Inocente Domingos

    2016-12-01

    especially the AC+rubber and the AC+rubber+PPA. The AC+PPA showed low stress sensitivity and the best results for the parameters R and Jnr at 3,200 Pa either in the ASTM or the AASHTO protocols, which justifies its choice as the best formulation. The data from the modified asphalt binders suggest that the change from the ASTM protocol to the AASHTO one is recommended.

  2. Precast Slabs for Contingency Rigid Airfield Pavement Damage Repairs (BRIEFING SLIDES)

    Science.gov (United States)

    2010-04-01

    efficiency of using different precast concrete panel installation techniques for contingency repair of damaged airfield pavements . Fast-setting polymer ...AFRL-RX-TY-TP-2010-0055 PRECAST SLABS FOR CONTINGENCY RIGID AIRFIELD PAVEMENT DAMAGE REPAIRS (BRIEFING SLIDES) Reza Ashtiani Applied...Rigid Airfield Pavement Damage Repairs (BRIEFING SLIDES) FA4819-09-C-0028 62102F 4915 D1 4915D14E Ashtiani, Reza; *Hammons, Michael I. Applied Research

  3. Pre-Cast Concrete Panels for Contingency Rigid Airfield Pavement Damage Repairs

    Science.gov (United States)

    2010-06-01

    Micro- texture of the particle plays an important role in aggregate interlock. Therefore, mixes consisting of less polished aggregates are expected to...AFRL-RX-TY-TR-2010-0095 PRECAST CONCRETE PANELS FOR CONTINGENCY RIGID AIRFIELD PAVEMENT DAMAGE REPAIRS Reza S. Ashtiani, Christopher J...Final Technical Report 01-JAN-2008 -- 30-APR-2010 Pre-Cast Concrete Panels for Rapid Repair of Airfield Rigid Pavements FA4819-09-C-0028 62102F 4915 D1

  4. Precast/Prestressed Concrete Experiments Performance on Non-Load Bearing Sandwich Wall Panels

    Science.gov (United States)

    2011-01-01

    AFRL-RX-TY-TR-2011-0021 PRECAST/ PRESTRESSED CONCRETE EXPERIMENTS PERFORMANCE ON NON-LOAD BEARING SANDWICH WALL PANELS Clay J. Naito...2008 -- 20-NOV-2010 Precast/ Prestressed Concrete Experiments Performance on Non-Loadbearing Sandwich Wall Panels FA8903-08-D-8768-0002 99999F GOVT F0...Wall Construction [TCA 2006] .............................................. 5 3. Prestressed Concrete Sandwich Wall Construction [PCI 1997

  5. Design Limits for Precast Concrete Sandwich Walls Subjected to External Explosions (PREPRINT)

    Science.gov (United States)

    2010-02-01

    Structures Congress, 12-14 May 2010, in Orlando FL. The use of precast/ prestressed concrete and tilt‐up concrete for exterior walls is common...Army Engineer Research & Development Center, CEERD-GS-V, 3909 Halls Ferry Road, Vicksburg, MS 39180. ABSTRACT The use of precast/ prestressed concrete ...developed based on historical data on the performance of reinforced concrete systems. The estimates for prestressed concrete systems are based on limited

  6. Anchorage Zone Design for Pretensioned Precast Bulb-T Bridge Girders in Virginia

    OpenAIRE

    E.D. Crispino; Cousins, Thomas E.; Roberts-Wollmann, Carin L.

    2009-01-01

    Precast/prestressed concrete girders are commonly used in bridge construction in the United States. The application and diffusion of the prestress force in a pretensioned girder cause a vertical tension force to develop near the end of the beam. Field surveys of the beam ends of pretensioned bridge girders indicate that many of the precast bulb-T (PCBT) beams used in Virginia develop cracks within the anchorage zone region. The lengths and widths of these cracks range from acceptable to poor ...

  7. Modeling of two-storey precast school building using Ruaumoko 2D program

    Science.gov (United States)

    Hamid, N. H.; Tarmizi, L. H.; Ghani, K. D.

    2015-05-01

    The long-distant earthquake loading from Sumatra and Java Island had caused some slight damages to precast and reinforced concrete buildings in West Malaysia such as cracks on wall panels, columns and beams. Subsequently, the safety of existing precast concrete building is needed to be analyzed because these buildings were designed using BS 8110 which did not include the seismic loading in the design. Thus, this paper emphasizes on the seismic performance and dynamic behavior of precast school building constructed in Malaysia under three selected past earthquakes excitations ; El Centro 1940 North-South, El Centro East-West components and San Fernando 1971 using RUAUMOKO 2D program. This program is fully utilized by using prototype precast school model and dynamic non-linear time history analysis. From the results, it can be concluded that two-storey precast school building has experienced severe damage and partial collapse especially at beam-column joint under San Fernando and El Centro North-South Earthquake as its exceeds the allowable inter-storey drift and displacement as specified in Eurocode 8. The San Fernando earthquake has produced a massive destruction to the precast building under viscous damping, ξ = 5% and this building has generated maximum building displacement of 435mm, maximum building drift of 0.68% and maximum bending moment at 8458kNm.

  8. The Significance of Coordination for Industrialised Building System (IBS Precast Concrete in Construction Industry

    Directory of Open Access Journals (Sweden)

    Fitri Othman Mohd Khairul

    2017-01-01

    Full Text Available IBS precast concrete is construction system which is meant to improve the conventional construction process. However IBS precast concrete projects are suffering from serious problems such as cost overrun, delays and less quality of the end product. The absence of coordination is perceived as the reason for this issue. The purpose of this paper is to review the significance of coordination for IBS precast concrete in the construction industry. It if found that the fragmentation which occurs in the construction industry requires continuity of coordination due to the construction activities are intertwined in nature. Coordination is designated to assist stakeholders in completing and complementing each other with the paramount focus of achieving the objective. Proper coordination is required in delivering the desired construction product at the ideal time, cost and quality. As for the findings, the significance of coordination for IBS precast concrete can be seen through the precast concrete construction phases which consist of planning; design; manufacturing; transportation and installation/construction. These phases are meant to complement construction process with the purpose to reduce issues of fragmentation and enhance IBS precast concrete project delivery.

  9. Spinning Induced Compression Strength of Precast Hollow Concrete Piles

    Directory of Open Access Journals (Sweden)

    Gogot Setyo Budi

    2017-09-01

    Full Text Available Prefabricated precast-hollow concrete pile is widely used as deep foundations due to its several benefits such as the uniformity in concrete quality and its durability. It is also called spun pile since the spinning method is utilized to compact the fresh concrete. During spinning, the fresh concrete is propelled outward due to centrifugal force, which generates a compaction process and develops a hollow in the center of the pile. Several factors, such as the rate of spinning, frequency, and duration of spinning, are affecting the quality of the pile. This paper presents the study of density and compressive strength of spun piles. The specimens were cored from the spun piles with diameter of 800 mm. The results show that the density and the compressive strength of the concrete at outer region of the spun pile are bigger than those at the inner side.

  10. Cost Effectiveness of Precast Reinforced Concrete Roof Slabs

    Science.gov (United States)

    Parskiy, N. D.; Molodtsov, M. V.; Molodtsova, V. E.

    2017-11-01

    Engineers always seek to free interior space from intermediate supporting elements. Nowadays plants, being at the forefront of technology, produce a new generation of exclusive patented prefabricated reinforced concrete elements with a high load-bearing capacity, excellent heat resistance characteristics combined with the aesthetics and beauty. It is a system of Seagull Gabbiano prestressed roof slabs for the spans of 12m - 40m. The article shows the advantages of the Seagull slabs over conventional precast reinforced concrete and metal roof trusses. It also gives the analysis of the technical and economic indices of design and construction of a building with the Seagull slabs depending on the size of spans to cover. The use of structural systems with increased spans allows for the modern buildings and structures of prefabricated reinforced concrete with enhanced functionality and aesthetics alongside with a wide range of planning solutions.

  11. Study on the Stiffness Correction Method of Novel Antivibration Bearing for Urban Rail Transit Viaduct

    Directory of Open Access Journals (Sweden)

    Weiping Xie

    2017-01-01

    Full Text Available A novel antivibration bearing is developed to reduce the train-induced vibrations for urban rail transit viaduct. It adopts four high-damping thick rubber blocks stacking slantingly to reduce the vibration and provide large lateral stiffness. But the existing stiffness calculation method of laminated rubber bearing aimed at horizontal seismic isolation is unsuitable for thick rubber bearing designed for vertical vibration reduction. First, the stiffness correction method has been proposed based on the characteristics of the novel bearing. Second, to validate the design method, mechanical property tests are performed on a specimen of the novel bearing with design frequency at 8 Hz and with 3500 kN bearing capacity. Third, damping effects of the novel bearing are investigated through impulse vibration tests on scaled models. Results show that the mechanical property of the novel bearing can satisfy the engineering demand, and the proposed method for calculating the stiffness agrees well with the test results. The overall insertion loss of the novel bearing is 13.49 dB which is 5.32 dB larger than that of steel bearing, showing that the novel bearing is very promising to be used in the field to mitigate train-induced vibrations.

  12. Flexural and Shear Behavior of FRP Strengthened AASHTO Type Concrete Bridge Girders

    Directory of Open Access Journals (Sweden)

    Nur Yazdani

    2016-01-01

    Full Text Available Fiber-reinforced polymers (FRP are being increasingly used for the repair and strengthening of deteriorated or unsafe concrete structures, including structurally deficient concrete highway bridges. The behavior of FRP strengthened concrete bridge girders, including failure modes, failure loads, and deflections, can be determined using an analytical finite element modeling approach, as outlined in this paper. The differences in flexural versus shear FRP strengthening and comparison with available design guidelines are also beneficial to design professionals. In this paper, a common AASHTO type prestressed concrete bridge girder with FRP wrapping was analyzed using the ANSYS FEM software and the ACI analytical approach. Both flexural and shear FRP applications, including vertical and inclined shear strengthening, were examined. Results showed that FRP wrapping can significantly benefit concrete bridge girders in terms of flexure/shear capacity increase, deflection reduction, and crack control. The FRP strength was underutilized in the section selected herein, which could be addressed through decrease of the amount of FRP and prestressing steel used, thereby increasing the section ductility. The ACI approach produced comparable results to the FEM and can be effectively and conveniently used in design.

  13. Cyclic performance and simplified pushover analyses of precast segmental concrete bridge columns with circular section

    Science.gov (United States)

    Bu, Zhanyu; Guo, Jian; Zheng, Rongyue; Song, Jianwei; Lee, George C.

    2016-06-01

    In recent years, precast segmental concrete bridge columns became prevalent because of the benefits of accelerated construction, low environmental impact, high quality and low life cycle costs. The lack of a detailed configuration and appropriate design procedure to ensure a comparable performance with monolithic construction has impeded this structural system from being widely used in areas of high seismicity. In this study, precast segmental bridge column cyclic loading tests were conducted to investigate the performance of unbonded post-tensioned segmental bridge columns. One monolithic and two precast segmental columns were tested. The precast segmental column exhibited minor damage and small residual displacement after the maximum 7% cyclic drift; energy dissipation (ED) can be enhanced byadding ED bars. The experimental results were modeled by a simplified pushover method (SPOM), as well as a fiber model (FIBM) finite element method. Forty-five cases of columns with different aspect ratios, axial load ratios and ED bar ratios were analyzed with the SPOM and FIBM, respectively. Using these parametric results, a simplified design method was suggested by regressive analysis. Satisfactory correlation was found between the experimental results and the simplified design method for precast segmental columns with different design parameters.

  14. Flexural Behaviour of Precast Aerated Concrete Panel (PACP with Added Fibrous Material: An Overview

    Directory of Open Access Journals (Sweden)

    Abdul Rahim Noor Hazlin

    2017-01-01

    Full Text Available The usage of precast aerated concrete panel as an IBS system has become the main alternative to conventional construction system. The usage of this panel system contributes to a sustainable and environmental friendly construction. This paper presents an overview of the precast aerated concrete panel with added fibrous material (PACP. PACP is fabricated from aerated foamed concrete with added Polypropylene fibers (PP. The influence of PP on the mechanical properties of PACP are studied and reviewed from previous research. The structural behaviour of precast concrete panel subjected to flexure load is also reviewed. It is found that PP has significant affects on the concrete mixture’s compressive stregth, tensile strength and flexural strength. It is also found that PP manage to control the crack propagation in the concrete panel.

  15. Tensile Capacity of U-bar Loop Connections with Precast Fiber Reinforced Dowels

    DEFF Research Database (Denmark)

    Sørensen, Jesper Harrild; Hoang, Linh Cao; Olesen, John Forbes

    2016-01-01

    This paper describes an investigation of the tensile capacity of in-situ cast U-bar loop connections between precast concrete elements. The basic idea is to introduce a small precast cylindrical dowel of fiber reinforced mortar that fits into the bend diameter of the overlapping U...... to ideal ductile behavior than that of the specimens grouted with regular mortar. The experimental results of the tensile tests are compared with calculations based on an upper bound plasticity model and satisfactory agreement has been obtained....... that use of a precast fiber reinforced dowel performs at a slightly lower load level, as compared to a connection grouted solely with regular mortar and reinforced with the same amount of transverse reinforcement. However, the load-displacement response of specimens with a fiber reinforced dowel is closer...

  16. Precast Prestressed Concrete Truss-Girder for Roof Applications

    Directory of Open Access Journals (Sweden)

    Peter Samir

    2014-01-01

    Full Text Available Steel trusses are the most popular system for supporting long-span roofs in commercial buildings, such as warehouses and aircraft hangars. There are several advantages of steel trusses, such as lightweight, ease of handling and erection, and geometric flexibility. However, they have some drawbacks, such as high material and maintenance cost, and low fire resistance. In this paper, a precast concrete truss is proposed as an alternative to steel trusses for spans up to 48 m (160 ft without intermediate supports. The proposed design is easy to produce and has lower construction and maintenance costs than steel trusses. The truss consists of two segments that are formed using standard bridge girder forms with block-outs in the web which result in having diagonals and vertical members and reduces girder weight. The two segments are then connected using a wet joint and post-tensioned longitudinally to form a crowned truss. The proposed design optimizes the truss-girder member locations, cross-sections, and material use. A 9 m (30 ft long truss specimen is constructed using self-consolidated concrete to investigate the constructability and structural capacity of the proposed design. A finite element analysis of the specimen is conducted to investigate stresses at truss diagonals, verticals, and connections. Testing results indicate the production and structural efficiency of the developed system.

  17. Development of a new connection for precast concrete walls subjected to cyclic loading

    Science.gov (United States)

    Vaghei, Ramin; Hejazi, Farzad; Taheri, Hafez; Jaafar, Mohd Saleh; Aziz, Farah Nora Aznieta Abdul

    2017-01-01

    The Industrialized Building System (IBS) was recently introduced to minimize the time and cost of project construction. Accordingly, ensuring the integration of the connection of precast components in IBS structures is an important factor that ensures stability of buildings subjected to dynamic loads from earthquakes, vehicles, and machineries. However, structural engineers still lack knowledge on the proper connection and detailed joints of IBS structure construction. Therefore, this study proposes a special precast concrete wall-to-wall connection system for dynamic loads that resists multidirectional imposed loads and reduces vibration effects (PI2014701723). This system is designed to connect two adjacent precast wall panels by using two steel U-shaped channels (i.e., male and female joints). During casting, each joint is adapted for incorporation into a respective wall panel after considering the following conditions: one side of the steel channel opens into the thickness face of the panel; a U-shaped rubber is implemented between the two channels to dissipate the vibration effect; and bolts and nuts are used to create an extension between the two U-shaped male and female steel channels. The developed finite element model of the precast wall is subjected to cyclic loads to evaluate the performance of the proposed connection during an imposed dynamic load. Connection performance is then compared with conventional connections based on the energy dissipation, stress, deformation, and concrete damage in the plastic range. The proposed precast connection is capable of exceeding the energy absorption of precast walls subjected to dynamic load, thereby improving its resistance behavior in all principal directions.

  18. SEISMIC SAFETY OF THE PRECAST BALCONY CANTILEVER ELEMENTS FOR PREVENTION OF THERMAL BRIDGES

    Directory of Open Access Journals (Sweden)

    Boris Azinović

    2014-12-01

    Full Text Available In the paper the seismic response of precast balcony cantilever structural elements for prevention of thermal bridges was analysed. This solution has been developed in seismic non-prone areas with the main purpose of eliminating a thermal bridge at the point where the balcony is fixed to the building. The solution has been specially made to withstand vertical static loading, not accounting for eventual vertical seismic loads in the case of transferring the solution to more active seismic zones. This paper deals with the seismic analysis of existent precast cantilever elements exposed to vertical accelerations and has proven that some elements in the case of lifting are not sufficient from the safety point of view. The results of the main research results obtained by numerous seismic analyses can be summarized as follows: 1 the insertion of a precast load-bearing thermal insulation element increases the flexibility of RC fixed base cantilevers and therefore limits their length to 300–400 cm, 2 vertical seismic loads can result in the cantilever uplift, which means that tensile stresses could appear also at the bottom of the cross-section 3 precast elements, that appear on the Slovenian market to this day, do not have the appropriate steel reinforcement in the bottom part of the cross-section. For this reason, the possibility of damage is considerably higher for precast cantilever structural elements than for RC fixed base cantilevers. Statistically calculated probability of cantilever uplift for Ljubljana, which would result in severe damage, is relatively low (3% in the 50-year life span. However, the calculated value is greater than the maximum acceptable level of seismic risk for collapse. One of the possible solutions to prevent the negative influences of cantilever uplift is to consider the proper reinforcement also at the bottom of the precast elements' crosssection, or by other measures preventing uplift.

  19. Prediction and mitigation analysis of ground vibration caused by running high-speed trains on rigid-frame viaducts

    Science.gov (United States)

    Sun, Liangming; Xie, Weiping; He, Xingwen; Hayashikawa, Toshiro

    2016-03-01

    In this study a 3D numerical analysis approach is developed to predict the ground vibration around rigid-frame viaducts induced by running high-speed trains. The train-bridge-ground interaction system is divided into two subsystems: the train-bridge interaction and the soil-structure interaction. First, the analytical program to simulate bridge vibration with consideration of train-bridge interaction is developed to obtain the vibration reaction forces at the pier bottoms. The highspeed train is described by a multi-DOFs vibration system and the rigid-frame viaduct is modeled with 3D beam elements. Second, applying these vibration reaction forces as input external excitations, the ground vibration is simulated by using a general-purpose program that includes soil-structure interaction effects. The validity of the analytical procedure is confirmed by comparing analytical and experimental results. The characteristics of high-speed train-induced vibrations, including the location of predominant vibration, are clarified. Based on this information a proposed vibration countermeasure using steel strut and new barrier is found effective in reducing train-induced vibrations and it satisfies environmental vibration requirements. The vibration screening efficiency is evaluated by reduction VAL based on 1/3 octave band spectral analysis.

  20. Performance-Based Seismic Design of Bitlis River Viaduct Based on Damage Control Using Seismic Isolation and Energy Dissipation Devices

    Science.gov (United States)

    Dicleli, Murat; Salem Milani, Ali

    2017-06-01

    This paper presents a sample application of seismic isolation techniques in performance-based design of a major viaduct. The Bitlis River viaduct is located in a seismically active region. The targeted performance goal required no damage at 475-year return period earthquake and repairable damage at 2475-year return period earthquake. The bridge is designed with a seismic isolation system composed of spherical bearings and MRSD (Multidirectional Re-centering steel Damper) hysteretic dampers. The MRSD is a recently-developed hysteretic damper with a controllable post-elastic stiffness. To keep the dampers from being activated during the thermal displacements, the attachment of the dampers to the deck are made through elongated holes oriented in the longitudinal direction of the bridge. The gaps are sized based on the amount of expected maximum thermal displacement in each pier. The gap length is thus different for different piers. This means that the number of the dampers to be engaged during an earthquake will depend on the intensity of the displacements. The distinct feature in this design is how it achieves double purpose: (i)preventing the dampers from engagement during service life as a result of thermal displacements and (ii) sequential engagement of the dampers depending on the level of seismically-induced displacements. The paper presents the basic design features of this seismically isolated bridge designed based on performance-based principles, a brief description of the newly-developed damper and a summary of analyses results.

  1. Structural Behavior and Design of Barrier-Overhang Connection in Concrete Bridge Superstructures Using AASHTO LRFD Method

    Directory of Open Access Journals (Sweden)

    Byungik Chang

    2012-01-01

    Full Text Available The U.S. Departments of Transportation adopted the AASHTO LRFD Bridge Design Specifications during the year 2007, which is mandated by AASHTO and FHWA. The application of LRFD specification initiated numerous research works in this field. This investigation addresses the LRFD and Standard design methodologies of concrete deck slab, deck overhang, barrier and combined barrier-bridge overhang. The purpose of this study is to propose a simplified manual design approach for the barrier-deck overhang in concrete bridges. For concrete deck slab overhang and barrier, application of National Cooperative Highway Research Program crash test is reviewed. The failure mechanism, design philosophy and load cases including extreme event limit states for barrier and overhang are discussed. The overhang design for the combined effect of bending moment and axial tension is probably the most important part of the design process. The overhang might be a critical design point of the deck with significantly higher amount of reinforcement. The design process becomes complicated due to combined force effect, LRFD crash test level requirement and the existence of several load combinations. Using this program, different LRFD load combinations are plotted together with the interaction diagram and the design is validated.

  2. Connections in Precast Buildings using Ultra High-Strength Fibre Reinforced Concrete

    DEFF Research Database (Denmark)

    Jensen, Bjarne Chr.; Jensen, Lars Rom; Hansen, F. Toft

    1995-01-01

    Precast elements have been used for decades in the building industry. Main reason for this are reduction in price, reduction in erection time, and increase of the quality as production in factories often reduce the possibility of faults. Since the beginning of the 70's, we have in Denmark made se...

  3. Double-curved precast concrete elements : Research into technical viability of the flexible mould method

    NARCIS (Netherlands)

    Schipper, H.R.

    2015-01-01

    The production of precast, concrete elements with complex, double-curved geometry is expensive due to the high costcosts of the necessary moulds and the limited possibilities for mould reuse. Currently, CNC-milled foam moulds are the solution applied mostly in projects, offering good aesthetic

  4. Partial depth precast concrete deck panels on curved bridges : finite element analytical model of PCPs.

    Science.gov (United States)

    2017-03-01

    A number of full-scale tests have been carried out in the laboratory focused on the shear : performance of simulated precast concrete deck panels (PCP). Shear tests were carried out to : simulate the type of loading that will be applied to the deck p...

  5. Three-dimensional submodel for modelling of joints in precast concrete structures

    DEFF Research Database (Denmark)

    Herfelt, Morten Andersen; Poulsen, Peter Noe; Hoang, Linh Cao

    2016-01-01

    The shear capacity of in-situ cast joints is crucial to the overall stability of precast concrete structures. The current design is based on empirical formulas, which account for neither the reinforcement layout of the joint nor the three-dimensional stress states present within the joint...

  6. Mathematical Model of Hybrid Precast Gravity Frames for Smart Construction and Engineering

    OpenAIRE

    Seon-Chee Park; Won-Kee Hong; Sunkuk Kim; Xiangyu Wang

    2014-01-01

    The structural stability, constructability, economic feasibility, environmental-friendliness, and energy efficiency of hybrid composite frame systems have been demonstrated by practical application and research. A hybrid composite frame system combines the economy of precast concrete structures with the constructability of steel frame structures, including erection speed. Novel composite frames will ultimately maximize the efficiency of structural design and facilitate construction. This pape...

  7. Performance and Characterization of Shear Ties for Use in Insulated Precast Concrete Sandwich Wall Panels

    Science.gov (United States)

    2010-11-01

    prestressed concrete ; composite; test; constitutive model U U U UU 21 Paul Sheppard Reset To be submitted to ASCE Structural Journal Page 1... Prestressed Concrete , Composite, Test, Constitutive 19 Model 20 21 1 Associate Professor...computes the shear demand 22 from the flexural capacity of the section. This method is recommended by the Precast/ Prestressed 23 Concrete Institute (PCI

  8. Application of yield line theory in pre-cast waffle slab | Akinyele ...

    African Journals Online (AJOL)

    Analysis of precast waffle slabs have concentrated on the rib portions, while the slab portion were left unanalyzed. This has led to cracks or outright failure of the slab portions due to under reinforcement. This paper proposed the use of yield line theory in solving this problem. Yield line theory was adopted to develop a ...

  9. Tests and limit analysis of loop connections between precast concrete elements loaded in tension

    DEFF Research Database (Denmark)

    Jørgensen, Henrik Brøner; Hoang, Linh Cao

    2013-01-01

    This paper deals with loop connections loaded in tension. Such connections; also known as U-bar joints, are frequently used in practice to establish continuity between precast deck elements in steel–concrete composite bridges. The tensile strength of a loop connection may either be governed by yi...

  10. Strength of precast concrete shear joints reinforced with high-strength wire ropes

    DEFF Research Database (Denmark)

    Joergensen, Henrik B.; Hoang, Linh Cao; Hagsten, Lars German

    2017-01-01

    This paper concerns the in-plane shear strength of connections between precast concrete wall elements reinforced with looped high-strength wire ropes. The looped wire ropes are pre-installed in so-called ‘wire boxes’ which function as shear keys. Although only a small amount of research on the sh...

  11. Monolithic Concrete vs Precast Concrete for the Construction of Bridge by Th Cantilever Method

    Directory of Open Access Journals (Sweden)

    Morlova Dumitru Daniel

    2015-07-01

    Full Text Available In the article "Monolithic Concrete vs Precast Concrete for the Construction of Bridges by the Cantilever Method", there are approached a number of issues that come out in the design and execution of prestressed concrete bridge structures using the cantilever method.

  12. PVC stay-in-place panel covers for tilt-up and pre-cast construction

    OpenAIRE

    ECT Team, Purdue

    2012-01-01

    Octaform™ stay-in-place concrete forming system is PVC insulated concrete form system. These forms have been used in the industry for various applications to improve the insulation and corrosion resistance of structures. Octaform™ has developed the panel covers so the advantages of PVC stay-in-place concrete forming systems could be applied to tilt-up and pre-cast construction.

  13. Anchorage zone design for pretensioned precast bulb-T bridge girders in Virginia.

    Science.gov (United States)

    2009-01-01

    Precast/prestressed concrete girders are commonly used in bridge construction in the United States. The application and diffusion of the prestress force in a pretensioned girder cause a vertical tension force to develop near the end of the beam. Fiel...

  14. Implementation of a Precast Inverted T-Beam System in Virginia: Part I : Laboratory Investigations

    Science.gov (United States)

    2017-10-01

    The inverted T-beam system provides an accelerated bridge construction alternative for short-to-medium-span bridges. The system consists of adjacent precast inverted T-beams with a cast-in-place concrete topping. This bridge system is not expected to...

  15. Investigation of panel-to-panel connections and block-outs for full-depth precast concrete bridge decks.

    Science.gov (United States)

    2015-06-01

    Experimental tests were performed at Virginia Tech to investigate transverse panel-to-panel connections and horizontal shear : connector block-outs for full-depth precast concrete bridge deck panels. The connections were designed for a deck replaceme...

  16. Durability of precast prestressed concrete piles in marine environment, part 2. Volume 2 : stainless steel prestressing strand and wire.

    Science.gov (United States)

    2012-06-01

    The overall purpose of this research was to determine methods which may be applied : economically to mitigate corrosion of reinforcement in precast prestressed concrete piles in : Georgias marine environments. The research was divided into two par...

  17. Damaged Concrete Viaduct in an Italian Highway: Concrete Characterization and Possible Strengthening Techniques by FRP Applications in Comparison

    Science.gov (United States)

    Tittarelli, Francesca; Ruello, Maria Letizia; Capuani, Domenico; Aprile, Alessandra

    2017-10-01

    The “Fornello” viaduct in the Italian Orte-Ravenna highway (E45) is seriously damaged. In this paper, the concrete of the reinforced slab has been widely characterized to evaluate the level of damage and to identify the causes of degradation. No-destructive tests, as those based on ultrasonic waves, as well as chemical, physical and mechanical destructive tests have been carried out on specimens drawn from deteriorated and not deteriorated zones of the R/C bridge decks. Into the slab thickness, the concentration distribution of main anions has been quantified by ion chromatography. Porosimetry tests have been carried out to detect the resistance to freeze-thaw cycles of cement paste. Possible strengthening techniques by FRP applications have been compared.

  18. Correlation between Wavelength Dispersive X-ray Fluorescence (WDXRF) analysis of hardened concrete for chlorides vs. Atomic Absorption (AA) analysis in accordance with AASHTO T- 260; sampling and testing for chloride ion in concrete and concrete raw mater

    Science.gov (United States)

    2014-04-01

    A correlation between Wavelength Dispersive X-ray Fluorescence(WDXRF) analysis of Hardened : Concrete for Chlorides and Atomic Absorption (AA) analysis (current method AASHTO T-260, procedure B) has been : found and a new method of analysis has been ...

  19. Research, Development and Application of High Performance Earthquake Resistant Precast System as Green Construction in Indonesia

    OpenAIRE

    Nurjaman Hari; Hariandja Binsar; Suprapto Gambiro; Faizal Lutfi; Sitepu Haerul

    2017-01-01

    Sustainable construction is a topic that emerges in the world construction as a response to climate change issue. Building construction stage is a stage in sustainable development. Construction concept that confirm to the concept is referred to as green construction. Precast concrete construction is a construction system that meets green construction criteria, because applies the usage of material and construction method that optimize energy consumption and minimize environment impact during ...

  20. Development of a Skewed Pipe Shear Connector for Precast Concrete Structures.

    Science.gov (United States)

    Kim, Sang-Hyo; Choi, Jae-Gu; Park, Sejun; Lee, Hyunmin; Heo, And Won-Ho

    2017-05-13

    Joint connection methods, such as shear key and loop bar, improve the structural performance of precast concrete structures; consequently, there is usually decreased workability or constructional efficiency. This paper proposes a high-efficiency skewed pipe shear connector. To resist shear and pull-out forces, the proposed connectors are placed diagonally between precast concrete segments and a cast-in-place concrete joint part on a girder. Design variables (such as the pipe diameter, length, and insertion angle) have been examined to investigate the connection performance of the proposed connector. The results of our testing indicate that the skewed pipe shear connectors have 50% higher ductility and a 15% higher ratio of maximum load to yield strength as compared to the corresponding parameters of the loop bar. Finite element analysis was used for validation. The resulting validation indicates that, compared to the loop bar, the skewed pipe shear connector has a higher ultimate shear and pull-out resistance. These results indicate that the skewed pipe shear connector demonstrates more idealized behavior than the loop bar in precast concrete structures.

  1. Experimental Study for Structural Behaviour of Precast Lightweight Panel (PLP) Under Flexural Load

    Science.gov (United States)

    Goh, W. I.; Mohamad, N.; Tay, Y. L.; Rahim, N. H. A.; Jhatial, A. A.; Samad, A. A. A.; Abdullah, R.

    2017-06-01

    Precast lightweight concrete slab is first fabricated in workshop or industrial before construction and then transported to site and installed by skilled labour. It can reduce construction time by minimizing user delay and time for cast-in-situ to increase workability and efficiency. is environmental friendly and helps in resource reduction. Although the foamed concrete has low compressive strength compared to normal weight concrete but it has excellent thermal insulation and sound absorption. It is environmental friendly and helps in resource reduction. To determine the material properties of foamed concrete, nine cubes and six cylindrical specimens were fabricated and the results were recorded. In this study, structural behaviour of precast lightweight panel (PLP) with dry density of 1800 kg/m3 was tested under flexural load. The results were recorded and analysed in terms of ultimate load, crack pattern, load-deflection profiles and strain distribution. Linear Voltage Displacement Transducers (LVDT) and strain gauges were used to determine the deflection and strain distribution of PLP. The theoretical and experimental ultimate load of PLP was analysed and recorded to be 70 and 62 kN respectively, having a difference of 12.9%. Based on the results, it can be observed that PLP can resist the adequate loading. Thus, it can be used in precast industry for construction purposes.

  2. User costs as one of main advantages of precast concrete application in highway construction

    Science.gov (United States)

    Tomek, Radan

    2017-09-01

    Road user cost primarily refer to the monetized components of road (re)construction impacts, such as the user delay costs, vehicle operating costs, crash costs and emission costs. Objective of this paper is to analyze and appraise the advantages and benefits of the innovative prefabrication approach in contrast to traditional cast-in-place construction method. The goal is to reduce these additional costs borne by motorists and the community at-large as a result of road construction activity to their minimum through application of the prefabrication. Assessing two basic possible approaches to highway infrastructure construction - casting the road pavements and structures either in place or precast off the site - it can be concluded that the initial capital investment costs do not vary much. Substantial differences can be recognized when comparing their life-cycle costs and an extent to which their construction process affects the public, environment and the local economy. Prefabrication of any structure component off-site offers major construction time and user cost savings in comparison with the traditional cast-in-place methods of construction. Precast prestressed road pavements’ technology and precasting bridges’ parts and elements offers dramatic increase in durability, while it also substantially decreases construction time and resulting user costs.

  3. Development of a Cantilever-Type Electrostatic Energy Harvester and Its Charging Characteristics on a Highway Viaduct

    Directory of Open Access Journals (Sweden)

    Hideaki Koga

    2017-09-01

    Full Text Available We have developed a micro-electro-mechanical systems (MEMS electrostatic vibratory power generator with over 100 μ W RMS of (root-mean-square output electric power under 0.03 G RMS (G: the acceleration of gravity accelerations. The device is made of a silicon-on-insulator (SOI wafer and is fabricated by silicon micromachining technology. An electret built-in potential is given to the device by electrothermal polarization in silicon oxide using potassium ions. The force factor, which is defined by a proportional coefficient of the output current with respect to the vibration velocity, is 2.34 × 10 − 4 C/m; this large value allows the developed vibration power generator to have a very high power efficiency of 80.7%. We have also demonstrated a charging experiment by using an environmental acceleration waveform with an average amplitude of about 0.03 G RMS taken at a viaduct of a highway, and we obtained 4.8 mJ of electric energy stored in a 44 μ F capacitor in 90 min.

  4. Strength of precast concrete shear joints reinforced with high-strength wire ropes

    DEFF Research Database (Denmark)

    Joergensen, Henrik B.; Hoang, Linh Cao; Hagsten, Lars German

    2017-01-01

    This paper concerns the in-plane shear strength of connections between precast concrete wall elements reinforced with looped high-strength wire ropes. The looped wire ropes are pre-installed in so-called ‘wire boxes’ which function as shear keys. Although only a small amount of research...... on the shear strength of such connections can be found in the literature, this type of connection is increasingly being used because wire ropes are much more construction-friendly than traditional U-bars. A rigid plastic upper bound model for the shear strength of wall connections reinforced with looped wire...

  5. Design and performance of self-consolidating concrete for connecting precast concrete deck panels and bridge I-girders.

    Science.gov (United States)

    2014-08-01

    Existing full-depth precast concrete deck systems use either open channels or pockets to accommodate the shear connectors of supporting girders for achieving composite systems. The use of open channels or pockets requires cast-in-place concrete/grout...

  6. Assessment of precast beam-column using capacity demand response spectrum subject to design basis earthquake and maximum considered earthquake

    Science.gov (United States)

    Ghani, Kay Dora Abd.; Tukiar, Mohd Azuan; Hamid, Nor Hayati Abdul

    2017-08-01

    Malaysia is surrounded by the tectonic feature of the Sumatera area which consists of two seismically active inter-plate boundaries, namely the Indo-Australian and the Eurasian Plates on the west and the Philippine Plates on the east. Hence, Malaysia experiences tremors from far distant earthquake occurring in Banda Aceh, Nias Island, Padang and other parts of Sumatera Indonesia. In order to predict the safety of precast buildings in Malaysia under near field ground motion the response spectrum analysis could be used for dealing with future earthquake whose specific nature is unknown. This paper aimed to develop of capacity demand response spectrum subject to Design Basis Earthquake (DBE) and Maximum Considered Earthquake (MCE) in order to assess the performance of precast beam column joint. From the capacity-demand response spectrum analysis, it can be concluded that the precast beam-column joints would not survive when subjected to earthquake excitation with surface-wave magnitude, Mw, of more than 5.5 Scale Richter (Type 1 spectra). This means that the beam-column joint which was designed using the current code of practice (BS8110) would be severely damaged when subjected to high earthquake excitation. The capacity-demand response spectrum analysis also shows that the precast beam-column joints in the prototype studied would be severely damaged when subjected to Maximum Considered Earthquake (MCE) with PGA=0.22g having a surface-wave magnitude of more than 5.5 Scale Richter, or Type 1 spectra.

  7. Production of Curved Precast Concrete Elements for Shell Structures and Free-form Architecture using the Flexible Mould Method

    NARCIS (Netherlands)

    Schipper, H.R.; Grünewald, S.; Eigenraam, P.; Raghunath, P.; Kok, M.A.D.

    2014-01-01

    Free-form buildings tend to be expensive. By optimizing the production process, economical and well-performing precast concrete structures can be manufactured. In this paper, a method is presented that allows producing highly accurate double curved-elements without the need for milling two expensive

  8. Modelling the behaviour of steel fibre reinforced precast beam-to-column connection

    Science.gov (United States)

    Chai, C. E.; Sarbini, NN; Ibrahim, I. S.; Ma, C. K.; Tajol Anuar, M. Z.

    2017-11-01

    The numerical behaviour of steel fibre reinforced concrete (SFRC) corbels reinforced with different fibre volume ratio subjected to vertical incremental load is presented in this paper. Precast concrete structures had become popular in the construction field, which offer a faster, neater, safer, easier and cheaper construction work. The construction components are prefabricated in controlled environment under strict supervision before being erected on site. However, precast beam-column connections are prone to failure due to the brittle properties of concrete. Finite element analysis (FEA) is adopted due to the nonlinear behaviour of concrete and SFRC. The key objective of this research is to develop a reliable nonlinear FEA model to represent the behaviour of reinforced concrete corbel. The developed model is validated with experimental data from previous researches. Then, the validated FEA model is used to predict the behaviour of SFRC corbel reinforced with different fibre volume ratio by changing the material parameters. The results show that the addition of steel fibre (SF) increases the load carrying capacity, ductility, stiffness, and changed the failure mode of corbel from brittle bending-shear to flexural ductile. On the other hand, the increasing of SF volume ratio also leads to increased load carrying capacity, ductility, and stiffness of corbel.

  9. Cement-base bearing pads mortar for connections in the precast concrete: study of surface roughness

    Directory of Open Access Journals (Sweden)

    M. K. El Debs

    Full Text Available Bearing pads are used in precast concrete connections to avoid concentrated stresses in the contact area between the precast elements. In the present research, the bearing pads are Portland cement mortar with styrene-butadiene latex (SB, lightweight aggregate (expanded vermiculite-term and short fibers (polypropylene, glass and PVA, in order to obtain a material with low modulus of elasticity and high tenacity, compared with normal Portland cement mortar. The objective of this paper is to analyze the influence of surface roughness on the pads and test other types of polypropylene fibers. Tests were carried out to characterize the composite and test on bearing pads. Characterization tests show compressive strength of 41MPa and modulus of elasticity of 12.8GPa. The bearing pads tests present 30% reduction of stiffness in relation to a reference mortar. The bearing pads with roughness on both sides present a reduction up to 30% in stiffness and an increase in accumulated deformation of more than 120%, regarding bearing pads with both sides smooth.

  10. Design, development, and application of precast and prestressed concrete system for rigid pavement in Indonesia

    Science.gov (United States)

    Nurjaman, Hari; Faizal, Lutfi; Suaryana, Nyoman; Hariandja, Binsar; Gambiro, Purnomo, Wicaksono, Siswo

    2017-11-01

    The performance of highways in Indonesia until today is yet to be optimum. Flexible or rigid pavement construction generally do not reach designed service lives, either due to the fact that the construction do not meet specifications or unavoidable excessive load. Precast and prestressed concrete system has been applied since 2007, but unfortunately the application has not been optimum due to the fact that the construction method is not integrally carried out. This paper deals with a construction concept that developed in 2015-2017. The concept applies green construction based on integrated manufacture industry, starting from design, construction, function, maintenance and demolition. The concept is applied on the three highway sub-layers, i.e., sub grade, sub base, and surface, and drainage system. Sub grade improvement may use soil dislocation, chemical improvement or concrete matress. Sub base material uses foam mortar, which is material easy in quality control compared to conventional materials. Pavement material uses precast and prestressed concrete components with controlled quality, quickly function as flexible pavement, and moreover, may anticipate excessive loadings. Cost estimation is carried out integrated by life cycle cost: initial investment, obstruction while construction, and maintenance cost during operation. This innovation has passed tests in technical construction method aspects as well as construction work in 2015-2017, so it is available to support infrastructure construction acceleration which achieves quality demanded to date.

  11. A numerical study on seismic response of self-centring precast segmental columns at different post-tensioning forces

    Directory of Open Access Journals (Sweden)

    Ehsan Nikbakht

    Full Text Available Precast bridge columns have shown increasing demand over the past few years due to the advantages of such columns when compared against conventional bridge columns, particularly due to the fact that precast bridge columns can be constructed off site and erected in a short period of time. The present study analytically investigates the behaviour of self-centring precast segmental bridge columns under nonlinear-static and pseudo-dynamic loading at different prestressing strand levels. Self-centring segmental columns are composed of prefabricated reinforced concrete segments which are connected by central post-tensioning (PT strands. The present study develops a three dimensional (3D nonlinear finite element model for hybrid post-tensioned precast segmental bridge columns. The model is subjected to constant axial loading and lateral reverse cyclic loading. The lateral force displacement results of the analysed columns show good agreement with the experimental response of the columns. Bonded post-tensioned segmental columns at 25%, 40% and 70% prestressing strand stress levels are analysed and compared with an emulative monolithic conventional column. The columns with a higher initial prestressing strand levels show greater initial stiffness and strength but show higher stiffness reduction at large drifts. In the time-history analysis, the column samples are subjected to different earthquake records to investigate the effect post-tensioning force levels on their lateral seismic response in low and higher seismicity zones. The results indicate that, for low seismicity zones, post-tensioned segmental columns with a higher initial stress level deflect lower lateral peak displacement. However, in higher seismicity zones, applying a high initial stress level should be avoided for precast segmental self-centring columns with low energy dissipation capacity.

  12. A PROPOSAL FOR AN ASSESSMENT METHOD OF THE DYNAMIC RESISTANCE OF CONCRETE SLAB VIADUCTS SUBJECTED TO IMPACT LOADS CAUSED BY MINING TREMORS

    Directory of Open Access Journals (Sweden)

    Janusz RUSEK

    Full Text Available The article presents a method for assessing dynamic resistance of existing reinforced concrete slab road viaducts subjected to mining tremors. For this purpose there are formulated six criteria to determine the maximum permissible value of the component ground vibrations (ax,dop, ay,dop, az,dop.Within each criterion, a reference is made to the most critical components, for which for which the Author has formulated strength and kinematic conditions, reflecting the behaviour of the structure under dynamic excitation caused by mining tremor. The permissible range of structural behaviour was set by comparing the effects of load combinations adopted at the design stage with a seismic combination proposed in [12]. In the field of dynamic analysis the response spectrum method was used, taking into account the guidelines for the adaptation of Eurocode 8 for the calculation the response of construction to the influence of mining tremors. Finally, in accordance with the established procedure calculations were carried out and and results are presented for a sample reinforced concrete slab road viaduct.

  13. Pseudo-dynamic tests on masonry residential buildings seismically retrofitted by precast steel reinforced concrete walls

    Science.gov (United States)

    Li, Wenfeng; Wang, Tao; Chen, Xi; Zhong, Xiang; Pan, Peng

    2017-07-01

    A retrofitting technology using precast steel reinforced concrete (PSRC) panels is developed to improve the seismic performance of old masonry buildings. The PSRC panels are built up as an external PSRC wall system surrounding the existing masonry building. The PSRC walls are well connected to the existing masonry building, which provides enough confinement to effectively improve the ductility, strength, and stiffenss of old masonry structures. The PSRC panels are prefabricated in a factory, significantly reducing the situ work and associated construction time. To demonstrate the feasibility and mechanical effectivenss of the proposed retrofitting system, a full-scale five-story specimen was constructed. The retrofitting process was completed within five weeks with very limited indoor operation. The specimen was then tested in the lateral direction, which could potentially suffer sigifnicant damage in a large earthquake. The technical feasibility, construction workability, and seismic performance were thoroughly demonstrated by a full-scale specimen construction and pseudo-dynamic tests.

  14. A method for the realization of complex concrete gridshell structures in pre-cast concrete

    DEFF Research Database (Denmark)

    Larsen, Niels Martin; Egholm Pedersen, Ole; Pigram, Dave

    2012-01-01

    This paper describes a method for the design and fabrication of complex funicular structures from discrete precast concrete elements. The research proposes that through the integration of digital form finding techniques, computational file-to-fabrication workflows and innovative sustainable...... in collaboration between the Aarhus School of Architecture and the University of Technology, Sydney (UTS). Basic research in casting techniques defined the framework for the design process, and a custom written dynamic relaxation software application became the primary form-generating tool in the design process...... of a constructed pavilion. Fabrication and construction constraints were embedded within the design of both the overall structure and its components. Finite Element Analysis [FEA] was completed in order to verify the form-finding results, to ensure structural stability, and to direct adjustments of the structure...

  15. Synthesis and Characterization of Functional Composite Carbon-Geopolymers for Precast Panel Application

    Directory of Open Access Journals (Sweden)

    Noor Afifah Kharisma

    2017-01-01

    Full Text Available The purpose of this study is to examine the influence of carbon (C particles as filler (aggregate in the production of geopolymers functional composite for possible precast panel application. Geopolymers was synthesized through alkali activation of metakaolin added with carbon particles relative to the mass of metakaolin. The mixture was cured at 70°C for 2 hours and the resulting composites were stored in open air for 28 days. The bulk density and the apparent porosity of the composites were measured by using Archimedes method. The thermal properties of the samples was examined by using thermal conductivity measurement and differential scanning calorimetry (DSC. The microstructure characterization of the samples were performed by using x-ray diffraction (XRD and Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS.

  16. Cost optimization of load carrying thin-walled precast high performance concrete sandwich panels

    DEFF Research Database (Denmark)

    Hodicky, Kamil; Hansen, Sanne; Hulin, Thomas

    2015-01-01

    The paper describes a procedure to find the structurally and thermally efficient design of load-carrying thin-walled precast High Performance Concrete Sandwich Panels (HPCSP) with an optimal economical solution. A systematic optimization approach is based on the selection of material’s performances...... and HPCSP’s geometrical parameters as well as on material cost function in the HPCSP design. Cost functions are presented for High Performance Concrete (HPC), insulation layer, reinforcement and include labour-related costs. The present study reports the economic data corresponding to specific manufacturing....... The solution of the optimization problem is performed in the computer package software Matlab® with SQPlab package and integrates the processes of HPCSP design, quantity take-off and cost estimation. The proposed optimization process outcomes in complex HPCSP design proposals to achieve minimum cost of HPCSP....

  17. Thermal Performance of Precast Concrete Sandwich Panel (PCSP) Design for Sustainable Built Environment

    Science.gov (United States)

    Ern, Peniel Ang Soon; Ling, Lim Mei; Kasim, Narimah; Hamid, Zuhairi Abd; Masrom, Md Asrul Nasid Bin

    2017-10-01

    Malaysia’s awareness of performance criteria in construction industry towards a sustainable built environment with the use of precast concrete sandwich panel (PCSP) system is applied in the building’s wall to study the structural behaviour. However, very limited studies are conducted on the thermal insulation of exterior and interior panels in PCSP design. In hot countries such as Malaysia, proper designs of panel are important to obtain better thermal insulation for building. This study is based on thermal performance of precast concrete sandwich panel design for sustainable built environment in Malaysia. In this research, three full specimens, which are control specimen (C), foamed concrete (FC) panels and concrete panels with added palm oil fuel ash (FC+ POFA), where FC and FC+POFA sandwiched with gypsum board (G) were produced to investigate their thermal performance. Temperature difference of exterior and interior surface of specimen was used as indicators of thermal-insulating performance of PCSP design. Heat transfer test by halogen lamp was carried out on three specimens where the exterior surface of specimens was exposed to the halogen lamp. The temperature reading of exterior and interior surface for three specimens were recorded with the help of thermocouple. Other factors also studied the workability, compressive strength and axial compressive strength of the specimens. This study has shown that FC + POFA specimen has the strength nearer to normal specimen (C + FC specimen). Meanwhile, the heat transfer results show that the FC+POFA has better thermal insulation performance compared to C and FC specimens with the highest temperature difference, 3.4°C compared to other specimens. The results from this research are useful to be implemented in construction due to its benefits such as reduction of energy consumption in air-conditioning, reduction of construction periods and eco-friendly materials.

  18. Behaviour of partially composite precast concrete sandwich panels under flexural and axial loads

    Science.gov (United States)

    Tomlinson, Douglas George

    Precast concrete sandwich panels are commonly used on building exteriors. They are typically composed of two concrete wythes that surround rigid insulation. They are advantageous as they provide both structural and thermal resistance. The structural response of sandwich panels is heavily influenced by shear connectors that link the wythes together. This thesis presents a study on partially composite non-prestressed precast concrete wall panels. Nine flexure tests were conducted on a wall design incorporating 'floating' concrete studs and Glass Fibre Reinforced Polymer (GFRP) connectors. The studs encapsulate and stiffen the connectors, reducing shear deformations. Ultimate loads increased from 58 to 80% that of a composite section as the connectors' reinforcement ratio increased from 2.6 to 9.8%. This design was optimized by reinforcing the studs and integrating them with the structural wythe; new connectors composed of angled steel or Basalt-FRP (BFRP) were used. The load-slip response of the new connector design was studied through 38 double shear push-through tests using various connector diameters and insertion angles. Larger connectors were stronger but more likely to pull out. Seven flexure tests were conducted on the new wall design reinforced with different combinations of steel and BFRP connectors and reinforcement. Composite action varied from 50 to 90% depending on connector and reinforcement material. Following this study, the axial-bending interaction curves were established for the new wall design using both BFRP and steel connectors and reinforcement. Eight panels were axially loaded to predesignated loads then loaded in flexure to failure. A technique is presented to experimentally determine the effective centroid of partially composite sections. Beyond the tension and compression-controlled failure regions of the interaction curve, a third region was observed in between, governed by connector failure. Theoretical models were developed for the bond

  19. Evaluation Analysis of the CO2 Emission and Absorption Life Cycle for Precast Concrete in Korea

    Directory of Open Access Journals (Sweden)

    Taehyoung Kim

    2016-07-01

    Full Text Available To comply with recent international trends and initiatives, and in order to help achieve sustainable development, Korea has established a greenhouse gas (GHG emission reduction target of 37% (851 million tons of the business as usual (BAU rate by 2030. Regarding environmentally-oriented standards such as the IGCC (International Green Construction Code, there are also rising demands for the assessment on CO2 emissions during the life cycle in accordance with ISO (International Standardization Organization’s Standard 14040. At present, precast concrete (PC engineering-related studies primarily cover structural and construction aspects, including improvement of structural performance in the joint, introduction of pre-stressed concrete and development of half PC. In the manufacture of PC, steam curing is mostly used for the early-strength development of concrete. In steam curing, a large amount of CO2 is produced, causing an environmental problem. Therefore, this study proposes a method to assess CO2 emissions (including absorption throughout the PC life cycle by using a life cycle assessment (LCA method. Using the proposed assessment method, CO2 emissions during the life cycle of a precast concrete girder (PCG were assessed. In addition, CO2 absorption was assessed against a PCG using conventional carbonation and CO2 absorption-related models. As a result, the CO2 emissions throughout the life cycle of the PCG were 1365.6 (kg-CO2/1 PCG. The CO2 emissions during the production of raw materials among the CO2 emissions throughout the life cycle of the PCG were 1390 (kg-CO2/1 PCG, accounting for a high portion to total CO2 emissions (nearly 90%. In contrast, the transportation and manufacture stages were 1% and 10%, respectively, having little effect on total CO2 emissions. Among the use of the PCG, CO2 absorption was mostly decided by the CO2 diffusion coefficient and the amount of CO2 absorption by cement paste. The CO2 absorption by carbonation

  20. Viability of utilization of waste materials from ceramic products in precast concretes

    Directory of Open Access Journals (Sweden)

    Sánchez de Rojas, M. I.

    2001-12-01

    Full Text Available The recycled and re-valuation process of waste materials involves studies lead to a deep acknowledges of them, finding applications for their intended use. The waste materials from ceramic products can be recycled into the construction sector, as arid or pozzolanic materials. The current work deals with the incorporation of ceramic materials in these two different ways, checking the behaviour of the elaborated mortar by mean of laboratory tests. Also, tests are developed in factory, using these as components for precast concrete tiles.

    Todo proceso de reciclado y revalorización de residuos implica estudios encaminados a un conocimiento profundo de los mismos, de forma que se busquen aplicaciones concretas de uso. Los materiales de desecho procedentes de productos cerámicos pueden ser reciclados dentro del sector de la construcción, ya sea como áridos o como materiales puzolánicos. El presente trabajo aborda la incorporación de materiales cerámicos desde estas dos vertientes, comprobando, en cada caso, el comportamiento de los morteros elaborados mediante ensayos de laboratorio. También se llevan a cabo pruebas en fábrica, siendo utilizados como componentes en prefabricados de hormigón.

  1. Constraint-aware interior layout exploration for pre-cast concrete-based buildings

    KAUST Repository

    Liu, Han

    2013-05-03

    Creating desirable layouts of building interiors is a complex task as designers have to manually adhere to various local and global considerations arising from competing practical and design considerations. In this work, we present an interactive design tool to create desirable floorplans by computationally conforming to such design constraints. Specifically, we support three types of constraints: (i) functional constraints such as number of rooms, connectivity among the rooms, target room areas, etc.; (ii) design considerations such as user modifications and preferences, and (iii) fabrication constraints such as cost and convenience of manufacturing. Based on user specifications, our system automatically generates multiple floor layouts with associated 3D geometry that all satisfy the design specifications and constraints, thus exposing only the desirable family of interior layouts to the user. In this work, we focus on pre-cast concrete-based constructions, which lead to interesting discrete and continuous optimization possibilities. We test our framework on a range of complex real-world specifications and demonstrate the control and expressiveness of the exposed design space relieving the users of the task of manually adhering to non-local functional and fabrication constraints. © 2013 Springer-Verlag Berlin Heidelberg.

  2. Semi-Active Control of Precast RC Columns under Seismic Action

    Science.gov (United States)

    Caterino, Nicola; Spizzuoco, Mariacristina

    2017-10-01

    This work is inspired by the idea of dissipating seismic energy at the base of prefabricated RC columns via semi-active (SA) variable dampers exploiting the base rocking. It was performed a wide numerical campaign to investigate the seismic behaviour of a pre-cast RC column with a variable base restraint. The latter is based on the combined use of a hinge, elastic springs, and magnetorheological (MR) dampers remotely controlled according to the instantaneous response of the structural component. The MR devices are driven by a SA control algorithm purposely written to modulate the dissipative capability so as to reduce base bending moment without causing excessive displacement at the top. The proposed strategy results to be really promising, since the base restraint relaxation, that favours the base moment demand reduction, is accompanied by a high enhancement of the dissipated energy due to rocking that can be even able to reduce top displacement in respect to the “fixed base rotation” conditions.

  3. Beneficial reuse of precast concrete industry sludge to produce alkaline stabilized biosolids.

    Science.gov (United States)

    Gowda, C; Seth, R; Biswas, N

    2008-01-01

    The precast concrete industry generates waste called concrete sludge during routine mixer tank washing. It is highly alkaline and hazardous, and typically disposed of by landfilling. This study examined the stabilization of municipal sewage sludge using concrete sludge as an alkaline agent. Sewage sludge was amended with 10 to 40% of concrete sludge by wet weight, and 10 and 20% of lime by dry weight of the sludge mix. Mixes containing 30 and 40% of concrete sludge with 20% lime fulfilled the primary requirements of Category 1 and 2 (Canada) biosolids of maintaining a pH of 12 for at least 72 hours. The heavy metals were below Category 1 regulatory limits. The 40% concrete sludge mix was incubated at 52 degrees C for 12 of the 72 hours to achieve the Category 1 and 2 regulations of less than 1000 fecal coliform/g solids. The nutrient content of the biosolids was 8.2, 10 and 0.6 g/kg of nitrogen, phosphorus and potassium respectively. It can be used as a top soil or augmented with potassium for use as fertilizer. The study demonstrates that concrete sludge waste can be beneficially reused to produce biosolids, providing a long-term sustainable waste management solution for the concrete industry.

  4. Structural Health Monitoring of Precast Concrete Box Girders Using Selected Vibration-Based Damage Detection Methods

    Directory of Open Access Journals (Sweden)

    Zhengjie Zhou

    2010-01-01

    Full Text Available Precast, prestressed concrete box girders are commonly used as superstructure components for short and medium span bridges. Their configuration and typical side-by-side placement make large portions of these elements inaccessible for visual inspection or the application of nondestructive testing techniques. This paper demonstrates that vibration-based damage detection (VBDD is an effective alternative for monitoring their structural health. A box girder removed from a dismantled bridge was used to evaluate the ability of five different VBDD algorithms to detect and localize low levels of spalling damage, with a focus on using a small number of sensors and only the fundamental mode of vibration. All methods were capable of detecting and localizing damage to a region within approximately 1.6 times the longitudinal spacing between as few as six uniformly distributed accelerometers. Strain gauges configured to measure curvature were also effective, but tended to be susceptible to large errors in near support damage cases. Finite element analyses demonstrated that increasing the number of sensor locations leads to a proportional increase in localization accuracy, while the use of additional modes provides little advantage and can sometimes lead to a deterioration in the performance of the VBDD techniques.

  5. Influence of the wind direction on the chloride profiles of structures close to the Caribbean Sea. The case of the Turiguanó- Coco Key Viaduct in Cuba

    Directory of Open Access Journals (Sweden)

    Pérez García, E. J.

    2005-03-01

    Full Text Available Interpretation of chlorides profiles is important to predict concrete structures service life, among other factors. However, reported results are, in general, from small specimens exposed to specific atmospheres instead of real structures. The objective of this work was the obtention and interpretation of the chlorides profiles forms from several bridges of the Turiguanó-Coco Key viaduct in Cuba. The results verified data from other authors but on different structural elements and similar atmospheres. The form of the chloride profile for structures similar to those in the viaduct bridges, exposed to tropical marine atmosphere, is consistent and changes in intensity with the winds direction and the blocking to them by parts of the structure. The possible effect of the wet and drying process is also discussed.

    En años recientes se le ha dado importancia a la interpretación de los perfiles de cloruros en el hormigón armado con fines de predicción de vida útil, entre otros. Sin embargo, los datos que se han constatado pertenecen, por lo general, a experimentos sobre probetas que han sido expuestas, por un tiempo determinado, a atmósferas específicas más que a estructuras reales. El objetivo de este trabajo fue la obtención e interpretación de la forma de los perfiles de cloruros de varios puentes del viaducto Turiguanó-Cayo Coco en Cuba. Los resultados ratificaron los datos encontrados por otros autores en otros elementos y ambientes similares, pero en un tipo de estructura diferente. En todos los casos estudiados se pudo verificar que, la forma del perfil de concentración de cloruros para estructuras similares a los puentes del viaducto estudiado expuestas a un ambiente tropical marino, es consistente y cambia de intensidad con la dirección de los vientos y del apantallamiento a los mismos por parte de la estructura y de sus partes. Se discute el posible efecto del mojado y secado.

  6. Shear Performance of Horizontal Joints in Short Precast Concrete Columns with Sleeve Grouted Connections under Cyclic Loading

    OpenAIRE

    Feng, Bo; Xiong, Feng; Liu, Bingyu; Chen, Jiang; Zhang, Yiping

    2016-01-01

    In this study, two short precast concrete columns and two cast-in-situ concrete columns were tested under cyclic loads. It was shown that the sleeve grouted connection was equivalent to the cast-in-situ connections for short columns when the axial compression ratio was 0.6. In order to determine the influence of the axial compression ratio and the shear-span ratio on the shear capacity of the horizontal joint, a FE model was established and verified. The analysis showed that the axial compres...

  7. Underground Parking structure built with deep foundations and vault precast elements in Spain

    Directory of Open Access Journals (Sweden)

    Fernández-Ordóñez, D.

    2012-09-01

    Full Text Available In many cases the only places available for the construction of a new car park are the existing streets or roads. These streets may also have important or historic buildings very close to the structure, which means that they cannot be disturbed in any way during the construction of the parking structure. In this particular case, the novelty is that the top deck is solved with a unique structure: a vault that interacts with the pile wall not only for vertical but also for horizontal loads due to the arch mechanism. The construction of the vault is solved as a large precast element of one piece of more than 16 in length and 2.40m in width, which is built in the factory, transported with the help of trucks and erected on site with large cranes.

    En muchos casos las únicas localizaciones para construir aparcamientos son las calles o carreteras. Estas calles también suelen tener alrededor importantes edificios históricos muy cercanos a la propia estructura. En este caso particular la novedad reside en que el forjado superior está resuelto con una estructura especial: una bóveda que interacciona con la pantalla de pilotes no solo en el sentido vertical sino también en el horizontal formando un verdadero mecanismo de arco. La construcción de la bóveda se ha resuelto con grandes elementos prefabricados de una pieza de más de 16m de longitud y de 2,40m de ancho. Se han fabricado en una factoría, transportados y montados en obra con grandes grúas.

  8. A High-Speed Target-Free Vision-Based Sensor for Bus Rapid Transit Viaduct Vibration Measurements Using CMT and ORB Algorithms

    Directory of Open Access Journals (Sweden)

    Qijun Hu

    2017-06-01

    Full Text Available Bus Rapid Transit (BRT has become an increasing source of concern for public transportation of modern cities. Traditional contact sensing techniques during the process of health monitoring of BRT viaducts cannot overcome the deficiency that the normal free-flow of traffic would be blocked. Advances in computer vision technology provide a new line of thought for solving this problem. In this study, a high-speed target-free vision-based sensor is proposed to measure the vibration of structures without interrupting traffic. An improved keypoints matching algorithm based on consensus-based matching and tracking (CMT object tracking algorithm is adopted and further developed together with oriented brief (ORB keypoints detection algorithm for practicable and effective tracking of objects. Moreover, by synthesizing the existing scaling factor calculation methods, more rational approaches to reducing errors are implemented. The performance of the vision-based sensor is evaluated through a series of laboratory tests. Experimental tests with different target types, frequencies, amplitudes and motion patterns are conducted. The performance of the method is satisfactory, which indicates that the vision sensor can extract accurate structure vibration signals by tracking either artificial or natural targets. Field tests further demonstrate that the vision sensor is both practicable and reliable.

  9. Optimization of Post-Tensioned Box Girder Bridges with Special Reference to Use of High-Strength Concrete Using AASHTO LRFD Method

    Directory of Open Access Journals (Sweden)

    Byungik Chang

    2012-01-01

    Full Text Available With the Federal Highway Administration-mandated implementation of the LRFD specifications, many state departments of transportation (DOTs have already started implementing LRFD specifications as developed by the AASHTO. Many aspects of the LRFD specifications are being investigated by DOTs and researchers in order for seamless implementation for design and analysis purposes. This paper presents the investigation on several design aspects of post-tensioned box girder bridges designed by LRFD Specifications using conventional or High-Strength Concrete (HSC. A computer spreadsheet application was specifically developed for this investigation. It is capable of analysis, design, and cost evaluation of the superstructure for a cast-in-place post-tensioned box girder bridge. Optimal design of a post-tensioned box girder is achievable by correct selection of design variables. Cost evaluation of superstructures with different geometrical and material configurations has led to the development of optimum design charts for these types of superstructures. Variables used to develop these charts include, among others, span length, section depth, web spacing, tendon profile, and concrete strength. It was observed that HSC enables the achievement of significantly longer span lengths and/or longer web spacing that is not achievable when using normal strength concrete.

  10. Using loose-fill perlite with normal weight precast wall panels to lower the cost, time of construction projects, and to provide an alternative to lightweight concrete

    Science.gov (United States)

    Al kulabi, Ahmed Kamil

    Lightweight concrete has been used in construction because of its properties, such as thermal, and fire resistances although it is more expensive and less available than normal weight concrete. One way to save time, cost, and to provide an alternative to lightweight concrete in construction projects is to reduce the number of installed insulations on precast wall panels and to improve the properties of normal weight concrete panels, respectively. These goals can be achieved by improving the four properties of precast panels, such as thermal resistance, fire resistance, heat capacity, and sound insulation by using perlite as insulation. The main goals of this research are getting buildings constructed or modified in less time and cost by producing superior wall panels and improving the properties of normal weight panels. Superior wall panels are new panels that provide the four properties listed above. Precast panels with different cross sections, concrete type, and different amounts of perlite will be investigated to observe the impact of each factor on the mentioned properties. The cost of each panel will be studied, and analytical methods will be used to find the optimum panel that provides the four mentioned properties with least cost. Moreover, theoretical methods will be applied to calculate the four properties for each panel. The preliminary theoretical calculations approved a good improvement in the four properties. In summary, the four properties of precast panels can be improved, time, and cost of construction can be reduced by using perlite as insulation.

  11. SEISMIC PERFORMANCE OF A PRECAST REINFORCED CONCRETE WALL WITH CUT-OUT OPENING RETROFITTED USING CARBON FIBRE STRIPS

    Directory of Open Access Journals (Sweden)

    Fofiu M.

    2015-05-01

    Full Text Available The Precast Reinforced Concrete Wall Panel (PRCWP presented in this paper is part of an experimental study regarding the seismic performance of precast reinforced concrete wall panels, strengthening strategies and investigation on the weakening induced by modifying the opening in these elements due to architectural demands, change of function of buildings or other reasons. The element presented is 1:1.2 scale typical Reinforced Concrete Wall Panel with a window opening used in Romania, in which the opening was changed to a door opening due to comfort considerations. The specimen was subjected to cyclic loading with the lateral loads being applied in displacement control of 0.1% drift ratio. This simulates the shear behaviour of the element. After testing the unstrengthen element we proceed to retrofit it using Carbon Fibre Strips anchored with Carbon Fibre Mash. The purpose of the paper is to present the strengthening strategy and restore the initial load bearing capacity of the element or even increase it. The experimental results of strengthen and unstrengthen specimens will be presented.

  12. Structural Behaviour of Precast Reinforced Concrete Frames on a Non-Engineered Building Subjected to Lateral Loads

    Directory of Open Access Journals (Sweden)

    Mochamad Teguh

    2016-06-01

    Full Text Available Past earthquakes in Indonesia have caused loss of life and major damage to buildings and infrastructure. Most of the damage was experienced on non-engineered buildings, which were conventionally built with less consideration of earthquake resistant design. In this research, a precast system was introduced for non-engineered building structures to connect their practical beams and columns as a reinforced concrete frame. This paper presents experimental tests on precast reinforced concrete frames with and without infill masonry walls using local materials. All undamaged and repaired specimens were set up with the same loading arrangements where lateral loads were gradually applied to one side of the beam column joint until the ultimate load was reached. Simple retrofitting and strengthening techniques were applied to the damaged specimens were conducted. The results were compared based on the experimental tests, and showed that retrofitted and strengthened specimens significantly increased their strength, stiffness, and displacement ductility to improve the structural behaviour of non-engineered building structures.

  13. Environmental performance and mechanical analysis of concrete containing recycled asphalt pavement (RAP) and waste precast concrete as aggregate.

    Science.gov (United States)

    Erdem, Savaş; Blankson, Marva Angela

    2014-01-15

    The overall objective of this research project was to investigate the feasibility of incorporating 100% recycled aggregates, either waste precast concrete or waste asphalt planning, as replacements for virgin aggregates in structural concrete and to determine the mechanical and environmental performance of concrete containing these aggregates. Four different types of concrete mixtures were designed with the same total water cement ratio (w/c=0.74) either by using natural aggregate as reference or by totally replacing the natural aggregate with recycled material. Ground granulated blast furnace slag (GGBS) was used as a mineral addition (35%) in all mixtures. The test results showed that it is possible to obtain satisfactory performance for strength characteristics of concrete containing recycled aggregates, if these aggregates are sourced from old precast concrete. However, from the perspective of the mechanical properties, the test results indicated that concrete with RAP aggregate cannot be used for structural applications. In terms of leaching, the results also showed that the environmental behaviour of the recycled aggregate concrete is similar to that of the natural aggregate concrete. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. ENERGY DEMANDS OF THE EXISTING COLLECTIVE BUILDINGS WITH BEARING STRUCTURE OF LARGE PRECAST CONCRETE PANELS FROM TIMISOARA

    Directory of Open Access Journals (Sweden)

    Pescari S.

    2015-05-01

    Full Text Available One of the targets of EU Directives on the energy performance of buildings is to reduce the energy consumption of the existing buildings by finding efficient solutions for thermal rehabilitation. In order to find the adequate solutions, the first step is to establish the current state of the buildings and to determine their actual energy consumption. The current paper aims to present the energy demands of the existing buildings with bearing structure of large precast concrete panels in the city of Timisoara. Timisoara is one of the most important cities in the west side of Romania, being on the third place in terms of size and economic development. The Census of Population and Housing of 2011 states that Timisoara has about 127841 private dwellings and 60 percent of them are collective buildings. Energy demand values of the existing buildings with bearing structure of large precast concrete panels in Timisoara, in their current condition, are higher than the accepted values provided in the Romanian normative, C107. The difference between these two values can reach up to 300 percent.

  15. Recycling power plant slag for use as aggregate in precast concrete components

    Directory of Open Access Journals (Sweden)

    Orna Carmona, M.

    2010-12-01

    Full Text Available The need to eliminate waste generates costs. When considering the preservation of the environment, the minimization of the consumption of natural resources and energy savings criteria, the need and advisability of studying the feasibility of waste re-use seems clear. However, waste re-use depends on whether they are economically competitive. Therefore, the aim of this study is to evaluate the possible use of slag from a steam power station as aggregate in the manufacture of concrete. This study included the determination of the physical, chemical and thermal properties of the material, comparing the results to those required by the Spanish structural concrete code (EHE in determining their acceptance or rejection as a concrete component. The ultimate aim of the research was to determine the highest slag content that could be added to concrete without modifying its strength or durability, with a view to obtaining savings in the manufacture of precast structures.

    La necesidad de eliminar residuos genera gastos. Considerando criterios de conservación ambiental, minimización del consumo de recursos naturales y ahorro de energía parece claro la necesidad y conveniencia de estudiar la viabilidad del uso de residuos. Sin embargo la utilización de residuos depende de que sean competitivos económicamente. Por tanto el propósito de esta investigación es evaluar el posible uso de las escorias de fondo de una central térmica como áridos para la fabricación de hormigón. En este estudio se incluye la determinación de características físicas, químicas y térmicas y se han comparado los resultados a los requeridos por la EHE para determinar su aceptación o rechazo como componente de un hormigón. El objetivo final de la investigación responde a la utilización de hormigón con el máximo contenido en escorias sin modificar las condiciones de resistencia y durabilidad, consiguiendo un ahorro económico en la fabricación de estructuras

  16. Application of the Hybrid Simulation Method for the Full-Scale Precast Reinforced Concrete Shear Wall Structure

    Directory of Open Access Journals (Sweden)

    Zaixian Chen

    2018-02-01

    Full Text Available The hybrid simulation (HS testing method combines physical test and numerical simulation, and provides a viable alternative to evaluate the structural seismic performance. Most studies focused on the accuracy, stability and reliability of the HS method in the small-scale tests. It is a challenge to evaluate the seismic performance of a twelve-story pre-cast reinforced concrete shear-wall structure using this HS method which takes the full-scale bottom three-story structural model as the physical substructure and the elastic non-linear model as the numerical substructure. This paper employs an equivalent force control (EFC method with implicit integration algorithm to deal with the numerical integration of the equation of motion (EOM and the control of the loading device. Because of the arrangement of the test model, an elastic non-linear numerical model is used to simulate the numerical substructure. And non-subdivision strategy for the displacement inflection point of numerical substructure is used to easily realize the simulation of the numerical substructure and thus reduce the measured error. The parameters of the EFC method are calculated basing on analytical and numerical studies and used to the actual full-scale HS test. Finally, the accuracy and feasibility of the EFC-based HS method is verified experimentally through the substructure HS tests of the pre-cast reinforced concrete shear-wall structure model. And the testing results of the descending stage can be conveniently obtained from the EFC-based HS method.

  17. Strain monitoring of a newly developed precast concrete track for high speed railway traffic using embedded fiber optic sensors

    Science.gov (United States)

    Crail, Stephanie; Reichel, D.; Schreiner, U.; Lindner, E.; Habel, Wolfgang R.; Hofmann, Detlef; Basedau, Frank; Brandes, K.; Barner, A.; Ecke, Wolfgang; Schroeder, Kerstin

    2002-07-01

    In a German slab track system (Feste Fahrbahn FF, system Boegl) for speeds up to 300 km/h and more different fiber optic sensors have been embedded in several levels and locations of the track system. The track system consists of prestressed precast panels of steel fiber concrete which are supported by a cat-in-situ concrete or asphalt base course. The sensors are to measure the bond behavior or the stress transfer in the track system. For that, tiny fiber-optic sensors - fiber Fabry-Perot and Bragg grating sensors - have been embedded very near to the interface of the layers. Measurements were taken on a full scale test sample (slab track panel of 6.45 m length) as well as on a real high speed track. The paper describes the measurement task and discusses aspects with regard to sensor design and prefabrication of the sensor frames as well as the embedding procedure into the concrete track. Results from static and dynamic full scale tests carried out in the testing laboratory of BAM and from measurements on a track are given.

  18. The use of bamboo and autoclaved aerated concrete block to reduce the weight of precast concrete beam

    Science.gov (United States)

    Dewi, Sri Murni; Simatupang, Roland Martin; Waluyohadi, Indra

    2017-09-01

    The lightweight structure is important for precast beam to reduce the dead loads and the handling loads. Steel reinforcement substitution with bamboo can be used to reduce the weight. For reinforced concrete beams, the concrete in tension side does not need a high compressive strength, hence it can be replaced with Autoclaved Aerated Concrete (AAC) Block. Purpose of this research is to study the strength and density behavior of the bamboo reinforced concrete beam substitute with the AAC block in tension area. The research variable was the portion of the AAC block height to the total beam height. The beam dimension was 16 cm × 20 cm × 200 cm. The concrete strength varied between 20 MPa and 25 MPa. Two variation of AAC block height were 6.5 cm and 8 cm. The beam tested in simple supported and two point loads. The control beam was made without AAC block, and 20 MPa concrete strength, and was used to compare the strength and the density of the beam. The experiment results show that the density of the beam varied between 1900 kg /m3 and 2000 kg/m3 and no significant decrease of the strength.

  19. Shear Performance of Horizontal Joints in Short Precast Concrete Columns with Sleeve Grouted Connections under Cyclic Loading.

    Science.gov (United States)

    Feng, Bo; Xiong, Feng; Liu, Bingyu; Chen, Jiang; Zhang, Yiping

    2016-01-01

    In this study, two short precast concrete columns and two cast-in-situ concrete columns were tested under cyclic loads. It was shown that the sleeve grouted connection was equivalent to the cast-in-situ connections for short columns when the axial compression ratio was 0.6. In order to determine the influence of the axial compression ratio and the shear-span ratio on the shear capacity of the horizontal joint, a FE model was established and verified. The analysis showed that the axial compression ratio is advantageous to the joint and the shear capacity of the horizontal joint increases with increase of the shear-span ratio. Based on the results, the methods used to estimate the shear capacity of horizontal joints in the Chinese Specification and the Japanese Guidelines are discussed and it was found that both overestimated the shear capacity of the horizontal joint. In addition, the Chinese Specification failed to consider the influence of the shear-span ratio.

  20. Shear Performance of Horizontal Joints in Short Precast Concrete Columns with Sleeve Grouted Connections under Cyclic Loading.

    Directory of Open Access Journals (Sweden)

    Bo Feng

    Full Text Available In this study, two short precast concrete columns and two cast-in-situ concrete columns were tested under cyclic loads. It was shown that the sleeve grouted connection was equivalent to the cast-in-situ connections for short columns when the axial compression ratio was 0.6. In order to determine the influence of the axial compression ratio and the shear-span ratio on the shear capacity of the horizontal joint, a FE model was established and verified. The analysis showed that the axial compression ratio is advantageous to the joint and the shear capacity of the horizontal joint increases with increase of the shear-span ratio. Based on the results, the methods used to estimate the shear capacity of horizontal joints in the Chinese Specification and the Japanese Guidelines are discussed and it was found that both overestimated the shear capacity of the horizontal joint. In addition, the Chinese Specification failed to consider the influence of the shear-span ratio.

  1. Flexural Behavior and Strut-and-tie Model of Joints with headed bar details Connecting Precast Members

    Directory of Open Access Journals (Sweden)

    Lungui Li

    2016-03-01

    Full Text Available This paper focuses on an investigation of an improved longitudinal joint with headed bar details connecting precast decked bulb tee girders for accelerated bridge construction. The testing study included two phases. In phase I, five beam specimens with various headed bar details and a continuous reinforced specimen were tested under flexure loadings. A headed bar detail with 152 mm lap length was recommended for further study. In phase II, two slabs connected by the selected joint were tested under flexure and flexure-shear loadings. Test results were evaluated based on structural behaviors including capacity, deflection, and failure mode. At last, a validated strut-and-tie model was developed to anticipate the capacity of the improved longitudinal joint. It shows that the proposed headed bar details can provide a continuous force transfer in the joint. The lap length interacting with the spacing of the headed bar is the most significant parameter of the improved joint details. To develop a full strength joint, the lap length should not be less than 152 mm and be designed by the strength requirement. The strut-and-tie model can provide a conservative strength anticipation of the joint and it is the lower bound of the ultimate capacity of the joint.

  2. Practical assessment of magnetic methods for corrosion detection in an adjacent precast, prestressed concrete box-beam bridge

    Science.gov (United States)

    Fernandes, Bertrand; Titus, Michael; Nims, Douglas Karl; Ghorbanpoor, Al; Devabhaktuni, Vijay Kumar

    2013-06-01

    Magnetic methods are progressing in the detection of corrosion in prestressing strands in adjacent precast, prestressed concrete box-beam bridges. This study is the first field trial of magnetic strand defect detection systems on an adjacent box-beam bridge. A bridge in Fayette County, Ohio, which was scheduled for demolition, was inspected. Damage to prestressed box-beams is often due to corrosion of the prestressing strands. The corroded strands show discontinuities and a reduced cross-sectional area. These changes, due to corrosion, are reflected in the magnetic signatures of the prestressing steel. Corrosion in the prestressing steel was detected using two magnetic methods, namely the 'magnetic flux leakage' (MFL) and the 'induced magnetic field'. The purpose of these tests was to demonstrate the ability of the magnetic methods to detect hidden corrosion in box-beams in the field and tackle the logistic problem of inspecting box-beams from the bottom. The inspections were validated by dissecting the bottom of the box-beams after the inspections. The results showed that the MFL method can detect hidden corrosion and strand breaks. Both magnetic field methods were also able to estimate corrosion by detecting the effective cross-sectional area of the strand in sections of the beams. Thus, it was shown that the magnetic methods can be used to predict hidden corrosion in prestressing strands of box-beams.

  3. Effect of section properties on load carrying capacity of 10m span precast concrete closed spandrel arch bridge with corrugated section

    Science.gov (United States)

    Ong, Chong Yong; Choong, Kok Keong; Miralimov, Mirzakhid

    2017-10-01

    Various precast concrete arch bridge systems have been developed since 1960's. The reinforced concrete section of these systems is solid rectangular which is not an efficient section. Inspired by the nature of banana tree trunk, a relatively new corrugated section of precast concrete arch bridge was introduced and patented in Malaysia in 2008. This folded plate section is an open section which tends to open under vehicular loading. Hence, effect of section properties on load carrying capacity of precast concrete closed spandrel arch bridge with corrugated section under vehicle loading is presented in this paper. The arch bridge model has a clear span of 10m with 2.5m, 3.0m and 3.5m clear rise. For the corrugated section dimension model, overall depth varies from 475mm to 575mm, top and bottom flange thickness varies from 135mm to 155mm and web thickness varies from 90mm to 120mm. Linear and non-linear computational analysis are carried out using 2D PLAXIS software (in longitudinal direction) and LUSAS software (in transverse direction). In longitudinal direction, the sagging moment in non-linear analysis increases approximately 18% compared to linear analysis for different rise span ratio. From the analysis results, as the rise of arch increases, the sagging moment and hogging moment increases, but the axial force decreases. Besides, as the overall depth of corrugated section increases, the internal forces of the arch also increase. In transverse direction, the maximum tensile stress of concrete at crown and haunch decreases as slenderness ratio increases.

  4. Influence of mix design parameters on dynamic segregation of self-consolidating concrete and consequences on performance of precast beams

    Science.gov (United States)

    Ley Hernandez, Aida Margarita

    Self-Consolidating Concrete (SCC) is more vulnerable to stability problems as a consequence of its high flowing ability compared to conventional vibrated concrete. Dynamic segregation refers to the tendency of the concrete constituents to separate from the suspended matrix, usually in horizontal direction while being cast into the formwork or due to an impact. Similarly to static segregation, dynamic segregation can affect the homogeneity of SCC. Therefore, it is highly essential to ensure a proper dynamic stability in order to enhance the uniformity of in-situ properties of pre-stressed beams. In this research project, the effects of SCC mix design parameters are investigated using the T-box test as a method to assess dynamic segregation. Changes in chemical admixture type and content, paste volume, sand-to-total aggregate ratio (S/A), w/cm and the width of the T-box have been evaluated. The results show that dynamic segregation of SCC is dependent on the rheological properties of the concrete, paste volume and S/A. In a second part, the influence of dynamic segregation on the uniformity of precast, pre-stressed beams is investigated. Six 9 m and three 18 m long beams were produced with SCC. To determine the uniformity of the mixture, a comparative survey across the beam height and along its length was performed. Also, the bond strength of pre-stress strands with SCC was investigated. Results from the UPV and compressive strength demonstrate a variation in the uniformity of the concrete, mainly at the casting point. For the bond strength, with increasing dynamic segregation, the bond between the strand and the concrete at the top 1/3rd of the beam height, relative to the bond in the middle 1/3rd, decreases.

  5. Contribution to assessing the stiffness reduction of structural elements in the global stability analysis of precast concrete multi-storey buildings

    Directory of Open Access Journals (Sweden)

    M. C. Marin

    Full Text Available This study deals with the reduction of the stiffness in precast concrete structural elements of multi-storey buildings to analyze global stability. Having reviewed the technical literature, this paper present indications of stiffness reduction in different codes, standards, and recommendations and compare these to the values found in the present study. The structural model analyzed in this study was constructed with finite elements using ANSYS® software. Physical Non-Linearity (PNL was considered in relation to the diagrams M x N x 1/r, and Geometric Non-Linearity (GNL was calculated following the Newton-Raphson method. Using a typical precast concrete structure with multiple floors and a semi-rigid beam-to-column connection, expressions for a stiffness reduction coefficient are presented. The main conclusions of the study are as follows: the reduction coefficients obtained from the diagram M x N x 1/r differ from standards that use a simplified consideration of PNL; the stiffness reduction coefficient for columns in the arrangements analyzed were approximately 0.5 to 0.6; and the variation of values found for stiffness reduction coefficient in concrete beams, which were subjected to the effects of creep with linear coefficients from 0 to 3, ranged from 0.45 to 0.2 for positive bending moments and 0.3 to 0.2 for negative bending moments.

  6. Design and construction of a cable-stayed composite girder bridge with precast RC-slabs; Purekyasuto shohan gosei keta shachokoyo no sekkei to seko

    Energy Technology Data Exchange (ETDEWEB)

    Maeda, K. [Tokyo Metropolitan Univ. (Japan). Faculty of Technology; Shimura, T.; Tachibana, Y.; Echigo, S. [Kawada Industries Inc., Tokyo (Japan)

    1995-09-20

    A report on design and execution of cable-stayed composite girder bridge with precast RC-slabs constructed first in Japan though in small scale was described. This bridge adopted steel slabs relatively low in slab height for main slab and with two boxes slab section, and was designed at an aim of being more economic and shorter in its working term in comparison with steel girder slab type, on a base of the design in a region allowable with the existing design standards. This bridge is mainly in accordance with the regulation on continuous bridge in the prescription of road bridge, and is designed for normal RC-girder selecting between girder supports to direction normal to bridge axis as usual without using specially strong concrete to the girder. And, in order to fill with the regulation on allowable tensile stress on considering effects of creep and drying shrinkage, a method adding prestress to the slabs was adopted. Furthermore, a loop-like overlap joint for cable joint for the precast girders, expansion concrete for joint portion to compose the girder with the steel slab and so forth were adopted. 12 refs., 22 figs., 5 tabs.

  7. Experiments on Hybrid Precast Concrete Shear Walls Emulating Monolithic Construction with Different Amounts of Posttensioned Strands and Different Debond Lengths of Grouted Reinforcements

    Directory of Open Access Journals (Sweden)

    Zhangfeng Zhu

    2016-01-01

    Full Text Available This paper proposed a hybrid precast concrete shear wall emulating monolithic construction (HPWEM that utilized grouted vertical connecting reinforcements and unbonded posttensioned high-strength strands across the horizontal joint for the lateral resistance. The grouted reinforcements with predetermined debond length were used to provide strength by tension and energy dissipation by yielding. The posttensioned strands were mainly employed to offer the restoring force to reduce the residual displacement by elastic extension. The overlapping welded closed stirrups improved the confinement property of the restrained concrete, avoiding the brittle failure. Six HPWEM specimens, considering variables including the amounts of strands and the debond lengths of grouted reinforcements, as well as one referenced cast-in-place monolithic wall specimen, were tested under the low-cycle reversed lateral load. The HPWEM specimens were capable of providing strength, stiffness, ductility, and energy dissipation equivalent to that of the monolithic wall specimen under certain variable condition.

  8. Properties of pre-cast terrazzo tiles and recommended specifications Propriedades de telhas de terrazzo pré-moldadas e especificações recomendadas

    Directory of Open Access Journals (Sweden)

    G. Karam

    2009-03-01

    Full Text Available A targeted experimental program was carried out to establish basic reference physical and mechanical properties of commercially available pre-cast marble chip terrazzo tiles and to investigate the effects of varying manufacturing process parameters on those properties. The transverse strength, density, water absorption, and abrasion resistance were measured as a function of casting pressure and residence time in the casting mold for a standard mix design. A simple surface abrasion index test was developed and applied comparing pre-cast terrazzo tiles with reference natural tiling stones. Recommendations for improving existing specifications and developing quality control measures are presented.Foi feito um programa experimental direcionado para estabelecer propriedades físicas e mecânicas como referências básicas de telhas de terrazzo de peças de mármore pré-moldadas disponíveis comercialmente e para investigar os efeitos de vários parâmetros de processo de fabricação nessas propriedades. A resistência transversal, a densidade, a absorção de água e a resistência ao desgaste foram medidas em função da pressão de moldagem e do tempo de residência do molde de um projeto de mistura padrão. Um teste simples de índice de desgaste de superfície foi desenvolvido e aplicado na comparação de telhas de terrazzo pré-moldadas com pedras de telhas naturais de referência. As recomendações para a melhoria das especificações existentes e o desenvolvimento de medidas para controle de qualidade são apresentadas.

  9. Study of potential advantages of pre-soaking on the properties of pre-cast concrete made with recycled coarse aggregate

    Directory of Open Access Journals (Sweden)

    Sánchez-Roldán, Z.

    2016-03-01

    Full Text Available Recycled aggregate (RA from construction and demolition waste is traditionally used for the manufacture of concrete for different applications. Due primarily to high water content required by RA, the quality of the concrete is determined by the amount of replacement RA. The aim of this study is to determine if RA pre-soaking enhances the properties of pre-cast concrete for street furniture, with low mechanical and structural requirements, in which 100% of the coarse fraction is replaced. The results of physical and mechanical tests performed on concrete specimens in which the RA was pre-soaked using five different methods applied are compared with a reference concrete sample and a concrete sample made with non-pre-soaked RA. The results show that non-pre-soaked RA offers improved physical-mechanical properties for pre-cast concrete, except for the workability; problems arising from poorer workability could be improved with the use of plasticizers, which can be easily included in the production process.El árido reciclado (AR procedente de residuos de construcción y demolición se utiliza tradicionalmente en la elaboración de hormigón para diferentes aplicaciones. Debido principalmente al mayor contenido en agua requerido por el AR, la calidad del hormigón está determinada por la cantidad de AR reemplazado. El objetivo de este estudio es determinar si el AR premojado mejora las propiedades del hormigón prefabricado para mobiliario urbano, con bajas exigencias mecánicas y estructurales, en el que se sustituye el 100% de la fracción gruesa. Los resultados de los ensayos físicos y mecánicos realizados sobre muestras de hormigón en las cuales el AR se ha premojado usando cinco métodos diferentes se han comparado con una muestra de hormigón de referencia y una muestra de hormigón fabricada con AR no premojado. Los resultados muestran que el AR no premojado proporciona propiedades físico-mecánicas mejoradas en el hormigón prefabricado

  10. Advanced Bridge Capacity and Structural Integrity Assessment Methodology

    Science.gov (United States)

    2013-03-01

    bridges , including reinforced concrete bridges with continuous girders across a support and prestressed structures. Identifying the class of...assessment of reinforced concrete bridges by making improved estimates of the level of longitudinal and shear reinforcement. The pro- posed assessment...Figure 7. AASHTO HS20-44 Truck (Precast/ Prestressed Concrete Institute 2003). ......................... 11 Figure 8. California Permit Truck (Caltrans

  11. Análise numérica e experimental de vigotas pré-moldadas em concreto armado para emprego em lajes nervuradas=Numerical and experimental analysis of precast reinforced concrete ribs for slabs.

    Directory of Open Access Journals (Sweden)

    Altevir Castro dos Santos

    2011-07-01

    Full Text Available Uma das aplicações mais comuns de elementos pré-moldados de concreto se dá nas lajes nervuradas de forro e piso. Numa concepção relativamente recente, surgiram lajes nervuradas pré-moldadas bidirecionais, feitas a partir de nervuras com armadura em forma de treliça espacial, com a possibilidade de uso de blocos de poliestireno expandido (EPS, com um formato diferenciado, como material de enchimento. Para se levar em conta a fissuração do concreto, no cálculo das deformações desse tipo de laje, neste trabalho foram adotados os modelos de momento-curvatura de Ghalli e Frave e de Branson, utilizando-se soluções lineares e não-lineares, por meio dos programas computacionais SAP2000® e ANSYS®. Esses modelos foram comparados com dados experimentais de vigas submetidas a ensaios de flexão pura. Também foi adotado um modelo tridimensional para a análise de vigas, baseado no elemento solid65 disponível no programa ANSYS®, o qual possibilita a análise não-linear de sólidos de materiais reforçados, como o concreto armado.One of the most common applications of precast concrete is done on ribbed slabs. A relatively recent conception emerged from precast concrete ribs with three-dimensional truss reinforcement. The use of expanded polystyrene (EPS blocks as a core material is possible in substitution of ceramic elements. To take into account the effect of concrete cracking on slab deformation, some theoretical models were considered in this work. These models were based on the moment-curvature equation of Ghalli and Frave and of Branson, using linear and non-linear solutions, through computer programs SAP2000® and ANSYS®. The theoretical values were compared to experimental data of beams tested under four-point loading. Also tested was a numerical solution for three-dimensional analysis of beams, based on the element solid65 available in the program ANSYS®, which allows non-linear analysis of solids with structural reinforcement

  12. Programa de Comparaciones Interlaboratoriales que organiza el AASHTO - NIST (AASHTO Materials Reference Laboratory - AMRL) para Laboratorios de Ensayos de Asfaltos

    OpenAIRE

    Jorge Grgich

    2011-01-01

    Un laboratorio debe llevar a cabo periódicamente controles de calidad internos y externos con la finalidad de verificar que sus resultados tienen una precisión y exactitud aceptable y mejorar en conjunto el funcionamiento del mismo. Dentro de los controles externos tenemos:Ensayos de Aptitud Interlaboratorio - " Proficiency Testing". La participación en estos ensayos permite al laboratorio comparar sus resultados frente a los de otros laboratorios que participan en dichos programas. Se expond...

  13. Programa de Comparaciones Interlaboratoriales que organiza el AASHTO - NIST (AASHTO Materials Reference Laboratory - AMRL para Laboratorios de Ensayos de Asfaltos

    Directory of Open Access Journals (Sweden)

    Jorge Grgich

    2011-04-01

    Full Text Available Un laboratorio debe llevar a cabo periódicamente controles de calidad internos y externos con la finalidad de verificar que sus resultados tienen una precisión y exactitud aceptable y mejorar en conjunto el funcionamiento del mismo. Dentro de los controles externos tenemos:Ensayos de Aptitud Interlaboratorio - " Proficiency Testing". La participación en estos ensayos permite al laboratorio comparar sus resultados frente a los de otros laboratorios que participan en dichos programas. Se expondrá con algunos ejemplos la evaluación de los resultados obtenidos como una manera de comprobar la calidad de los ensayos, y se señalan las medidas que se adoptan de ser necesario. El caso se refiere al Laboratorio de Asfaltos del LATU (Departamento Construcciones, acreditado por UKAS que participa en dicho programa. Mostraremos como se realiza la calificación de los resultados reportados por un laboratorio y presentaremos algunos de los resultados obtenidos a la fecha para los programas en los cuales participamos: AMRL Emulsified Asphalt Proficiency Sample Program AMRL Viscosity Graded Asphalt Cement Proficiency Sample Program AMRL Bituminous Asphalt Proficiency Sample Program

  14. Lightweight Building Floors Using Precast Reinforced Concrete ...

    African Journals Online (AJOL)

    The panels are designed based on loads of self-weight, partition wall, service and ceiling, screed and live load. The investigations have been focused on concrete usage, structural weight, and structural functions of both ultimate and service conditions. It has been observed that 'C-channels' are more economical and ...

  15. Flexible Mould for Precast Concrete Elements

    DEFF Research Database (Denmark)

    Jepsen, Christian Raun; Kristensen, Mathias Kræmmergaard; Kirkegaard, Poul Henning

    2010-01-01

    , both in-situ cast and modular. Today, such elements are usually cast in milled formwork that is expensive and produces a lot of waste. Architects are often limited in their freedom of design by the high costs of the existing methods and as a result, the possibilities for drawing and evaluating complex...

  16. Second generation precast deck panel (NUDECK) system.

    Science.gov (United States)

    2010-12-01

    "The majority of todays bridge decks are built using cast-in-place concrete construction. This is due to the perceived : low initial cost and constructor familiarity with the system. This research report describes the design, details, and : constr...

  17. Faster bridge construction using precast substructures : brief.

    Science.gov (United States)

    2011-07-01

    Bridge replacement often requires road closures and detours that frustrate road users. It remains a key goal of Wisconsin DOT to reduce construction-related road use interruptions. This will be a challenge with bridges: Bridge inspections in 2007 ide...

  18. Precast Pearl-Chain concrete arch bridges

    DEFF Research Database (Denmark)

    Halding, Philip Skov; Hertz, Kristian Dahl; Schmidt, Jacob Wittrup

    2015-01-01

    A Pearl-Chain Bridge is a closed-spandrel arch bridge consisting of a number of straight pre-fabricated so called Super-Light Deck elements put together in an arch shape by post-tensioning cables. Several Pearl-Chain arches can be positioned adjacent to each other by a crane to achieve a bridge...... the technology was used. We also study other important components and details in the Pearl-Chain Bridge concept and review the effects of different types of loads. A theoretical case study of a circular 30 m span Pearl-Chain Bridge is presented showing the influence of a number of parameters: The number of post......-tensioning cables, the rise to span ratio, the height of the filling, and the height of the Super-Light Decks. We find that Pearl-Chain Bridges can be adjusted to resist specific moment loads by changing the normal force in the arch cross section by altering the above parameters. It is also found that the negative...

  19. Force Time History During the Impact of a Barge Train with a Lock Approach Wall Using Impact_Force

    Science.gov (United States)

    2010-06-01

    cross-section of the hollow, prestressed concrete impact beam is shown in Figure A.4. The impact beam is 10 feet wide and 8 feet high.1 The impact face...Vessel Collision Design of Highway Bridges , Volume 1: Final Report, February 1991 (AASHTO 1991). Table 2.2 contains information on barge capacity...is a precast, prestressed hollow beam (i.e., flexible structure) with a length of 117 feet 7 3/4 inches. A cross-section of the hollow beam is shown

  20. Puente de Almodóvar sobre el río Guadalquivir, cerca de Córdoba

    Directory of Open Access Journals (Sweden)

    Fernández Casado, Carlos

    1967-02-01

    Full Text Available The Almodóvar Bridge is the first of several structural works forming part of the new Cordoba-Sevilla motorway. The construction procedure adopted—cantilever method by means of precast sections—is very interesting and will be used also for other similar bridges. The bridge structure, with its two approach viaducts, consists of a Gerber beam of prestressed concrete resting on two piers, including a central span of 70 m and two side cantilevers of 35 m. The suspended span, 30 m long, and the two approach viaducts are constituted by precast prestressed beams. The central cantilever arms of the Gerber beam are constructed by means of precast sections which are subsequently connected together by prestressing bars. The article describes the design principles, the bridge structure as well as the methods of construction.Es la primera de una serie de obras destinadas a la construcción de la autopista Córdoba-Sevilla. El método de voladizos sucesivos de hormigón pretensado que se ha adoptado para su construcción, es de gran interés y permitirá su empleo en obras posteriores. La estructura del puente, que está constituida por una viga Gerber apoyada en dos pilas intermedias, comprende un tramo central de 70 m de luz y dos vanos laterales de 35 m de luz cada uno de ellos. El tramo central está formado por una viga prefabricada de hormigón pretensado, de 30 m de luz, simplemente apoyada en dos voladizos de 20 m. Los tramos en voladizo se ejecutaron mediante elementos sucesivos prefabricados, solidarizados mediante los cables del pretensado. Completan la obra los dos viaductos de acceso, con tableros construidos con vigas pretensadas prefabricadas. Este artículo describe el proyecto y ejecución de la obra.

  1. Hot mix asphalt (HMA) characterization for the 2002 AASHTO design guide.

    Science.gov (United States)

    2008-09-30

    The two study objectives were to conduct dynamic modulus and APA rutting tests of selected Mississippi HMA mixtures. A total of twenty-five mixtures were tested including aggregate combinations of gravel and gravel/limestone; 9.5mm, 12.5mm and 19.0mm...

  2. Traffic and data preparation for AASHTO DARWin-ME analysis and design.

    Science.gov (United States)

    2015-02-01

    Pavement ME Design (MEPDG/DARWin-ME) is a significant advancement in pavement design, but : requires much more inputs from various sources. Through the transportation pooled fund study TPF- : 5(242), a full-production software Prep-ME with comprehens...

  3. Traffic and data preparation for AASHTO DARWin-ME analysis and design : [tech summary].

    Science.gov (United States)

    2015-02-01

    Although the Mechanistic Empirical Pavement Design Guide (MEPDG), now called Pavement ME Design, is a signi cant advancement : in pavement design, it requires much more input from designers. Many data sets, such as weigh-in-motion (WIM) tra c d...

  4. Update of bridge design standards in Alabama for AASHTO LRFD seismic design requirements.

    Science.gov (United States)

    2013-11-01

    The Alabama Department of Transportation (ALDOT) has been required to update their bridge design to the LRFD Bridge Design Specifications. This transition has resulted in changes to the seismic design standards of bridges in the state. Multiple bridg...

  5. Philippine mitochondrial DNA diversity: a populated viaduct between Taiwan and Indonesia?

    Science.gov (United States)

    Tabbada, Kristina A; Trejaut, Jean; Loo, Jun-Hun; Chen, Yao-Ming; Lin, Marie; Mirazón-Lahr, Marta; Kivisild, Toomas; De Ungria, Maria Corazon A

    2010-01-01

    Relatively little is known about the genetic diversity of the Philippine population, and this is an important gap in our understanding of Southeast Asian and Oceanic prehistory. Here we describe mitochondrial DNA (mtDNA) variation in 423 Philippine samples and analyze them in the context of the genetic diversity of other Southeast Asian populations. The majority of Philippine mtDNA types are shared with Taiwanese aboriginal groups and belong to haplogroups of postglacial and pre-Neolithic origin that have previously been identified in East Asian and Island Southeast Asian populations. Analysis of hypervariable segment I sequence variation within individual mtDNA haplogroups indicates a general decrease in the diversity of the most frequent types (B4a1a, E1a1a, and M7c3c) from the Taiwanese aborigines to the Philippines and Sulawesi, although calculated standard error measures overlap for these populations. This finding, together with the geographical distribution of ancestral and derived haplotypes of the B4a1a subclade including the Polynesian Motif, is consistent with southward dispersal of these lineages "Out of Taiwan" via the Philippines to Near Oceania and Polynesia. In addition to the mtDNA components shared with Taiwanese aborigines, complete sequence analyses revealed a minority of lineages in the Philippines that share their origins--possibly dating back to the Paleolithic--with haplogroups from Indonesia and New Guinea. Other rare lineages in the Philippines have no closely related types yet identified elsewhere.

  6. Dynamic Test of a Viaduct on the Orastie–Sibiu Highway

    Directory of Open Access Journals (Sweden)

    Lucian Ghindea Cristian

    2017-07-01

    Full Text Available Dynamic testing of bridges has as target to establish their response on pulse forces between the wheels and unevenness of road surface. Generally, during the tests, real time accelerations or deformations are to be measured and which through successive processing methods lead to other data as velocities, displacements, dynamic impact factor, but also the damping ratio. In order to validate the bridge response following testing, the measured data are compared both with allowable limits existing in standards and with the results obtained using analytical or numerical models.

  7. Heavy vehicle simulator testing on pre-cast concrete panels

    CSIR Research Space (South Africa)

    Du Plessis, L

    2007-07-01

    Full Text Available pavement slabs and perform in the same way. Dowel slots cast on the bottom of the slabs provide two benefits. First, they keep dowel grout on the bottom, protecting it from de-icing chemicals and degradation from freeze/ thaw activity. Secondly... an indication of their size, the brass sensor caps are 75mm in diameter). Drill cores obtained from various locations in both test sections indicated very good performance of the dowel grout. There was no sign of looseness of the dowel, which means...

  8. Design and construction of precast piles with stainless reinforcing steel.

    Science.gov (United States)

    2014-02-01

    The service life of prestressed concrete piles is, in part, dictated by the time required to corrode the steel once : chloride ions are at the surface of the steel. Stainless steel materials, although limited in availability in strand : form, have a ...

  9. Precast alternative for flat slab bridges : final report.

    Science.gov (United States)

    2013-10-26

    The cast-in-place (CIP) concrete slab bridge and the hollow core flat slab bridge are two very common bridge types utilized by the : South Carolina Department of Transportation (SCDOT). The CIP bridge is durable but has a long construction time while...

  10. Construction-friendly ductile shear joints for precast concrete panels

    DEFF Research Database (Denmark)

    Sørensen, Jesper Harrild; Hoang, Linh Cao; Fischer, Gregor

    2015-01-01

    for the mounting of a vertical locking bar. Where limited space is available bending and subsequent straightening of the U-bars are required to assemble the adjacent panels, a procedure which imposes substantial ductility requirements on the reinforcement as well as some manual workload. This paper introduces...

  11. Creep behavior of precast segmental box girder bridge

    Science.gov (United States)

    Xihua, Dai; Liangfang, Liu; Rong, Xian

    2017-08-01

    The concrete creep effect is more obvious when the box girder is assembled by segment. It is necessary to consider the influence of the loading value of the section at different time and the different age of concrete at different stages. In this paper, ACI209R-92, CEB-FIP MC90 and B3 and other concrete creep models are compared. The results show that the B3 model has many factors to consider and the calculation accuracy is high. Secondly, this paper discusses the influence of the segmental construction technology on the creep calculation, and puts forward the characteristics of the stress analysis of the segmental box girder. Finally, on the basis of the B3 model of concrete creep, the Midas software is used to establish the calculation model of segmental box girder, and the internal force and deformation of the box girder are calculated. The results show that the internal force and deformation of the box girder is too large due to the poor integrity of the segmental assembling process, which will seriously affect the normal service performance.

  12. Manufacturing Double Curved Precast Concrete Panels using a Flexible Mould

    NARCIS (Netherlands)

    Schipper, H.R.; Janssen, B.

    2011-01-01

    Free form architecture with complex geometry brings along new challenges for manufacturers of building components. This paper describes the application of structural mechanics to predict the behaviour of an elastic mould surface, used as formwork for the manufacturing of double curved panels in

  13. Thermal response testing of precast pile heat exchangers

    DEFF Research Database (Denmark)

    Pagola, Maria Alberdi; Poulsen, Søren Erbs; Jensen, Rasmus Lund

    The report is organized as follows: first, the concept of TRT is explained. Second, the test sites are described. Third, the field work is presented and a summary of the future work regarding the methodology to treat the data from the tests is provided. Finally, further documentation of the field...... of the fieldwork, the pile heat exchangers and the TRT equipment is extended in diverse appendices....

  14. Thermal response testing of precast pile heat exchangers: fieldwork report

    DEFF Research Database (Denmark)

    Alberdi Pagola, Maria; Poulsen, Søren Erbs; Jensen, Rasmus Lund

    Centrum Pæle A/S, Aalborg University, VIA University College and INSERO Horsens are partners in the industrial PhD project: “Experimental and numerical characterisation of the thermo-mechanical behaviour of quadratic cross section energy piles”. This document aims to present the fieldwork...

  15. Thermal response testing of precast pile heat exchangers

    DEFF Research Database (Denmark)

    Pagola, Maria Alberdi; Poulsen, Søren Erbs; Jensen, Rasmus Lund

    Centrum Pæle A/S, Aalborg University, VIA University College and INSERO Horsens are partners in the industrial PhD project: “Experimental and numerical characterisation of the thermo-mechanical behaviour of quadratic cross section energy piles”. This document aims to present the fieldwork...

  16. Stand pentru încercarea grinzilor precomprimate U 37m

    Directory of Open Access Journals (Sweden)

    Mircea Păstrav

    2011-03-01

    Full Text Available As part of conformity certification process of prefabricated beams used for bridges and viaducts on Transylvania Motorway, a prestressed concrete U-shaped beam of 37.10 m span with superior slab cast in situ was subjected to a resistance test. Due to beam overall dimensions of 3.30 x 2.50 x 37.10 m and to the important forces which have to be applied it has been necessary to build an adequate stand right near the precast site. Paper briefly presents the mechanical, technological, economical and work safety requirements, the design and the actual implementation of the one of the largest testing stands made în our country.

  17. Transfer and development length of prestressing tendons in full-scale AASHTO prestressed concrete girders using self-consolidating concrete.

    Science.gov (United States)

    2009-03-01

    Self-consolidating concrete (SCC) is a highly workable concrete that flows through densely reinforced or : complex structural elements under its own weight. The benefits of using SCC include: a) Reducing labor costs : by eliminating the need for mech...

  18. Connections in Precast Buildings using Ultra High-Strength Fibre Reinforced Concrete

    DEFF Research Database (Denmark)

    Hansen, Lars Pilegaard

    1995-01-01

    Ultra high-strength concrete adds new dimensions to the design of concrete structures. It is a brittle material but introducing fibres into the matrix changes the material into a highly ductile material. Furthermore, the fibre reinforcement increases the anchorage of traditional reinforcement bars...... and the fire resistance. Such a fibre reinforced ultra high-strength material has been used to develop a simple joint solution between slab elements in a column - slab building system....

  19. PRE-CAST WALL PRODUCTS MADE FROM LIGHTWEIGHT CONCRETE FOR ENCLOSING STRUCTURES OF BUILDINGS

    Directory of Open Access Journals (Sweden)

    M. R. Hadgiev

    2014-01-01

    Full Text Available The paper is devoted to the actual problem waste dismantling of buildings and structures in the form of brick waste with reception the secondary fine and coarse aggregate and concrete based on them for the manufacture of small-piece wall products. 

  20. The Use of Cyclone Modeling in the Erection of Precast Segmental Aerial Construction.

    Science.gov (United States)

    1983-06-01

    time study in steel mills in the 1880s, and continuing to evolve with the use of motion study by Frank Gilbreth to improve concrete and bricklaying...jobs at the turn of the century.2 1 As such, Gilbreth was the first to extensively apply the use of work improvement techniques in construction.22 Daniel

  1. Corrosion-free precast prestressed concrete piles made with stainless steel reinforcement : construction, test and evaluation.

    Science.gov (United States)

    2015-03-01

    The use of duplex high-strength stainless steel (HSSS) grade 2205 prestressing strand and : austenitic stainless steel (SS) grade 304 spiral wire reinforcement is proposed as a replacement of : conventional prestressing steel, in order to provide a 1...

  2. Realisation of complex precast concrete structures through the integration of algorithmic design and novel fabrication techniques

    DEFF Research Database (Denmark)

    Larsen, Niels Martin; Egholm Pedersen, Ole; Pigram, Dave

    2012-01-01

    . This involves consideration of the relations between geometry and technique, as well as the use of form-finding and simulation algorithms for shaping and optimising the shape of the structure. Custom-made scripts embedded in 3D-modeling tools were used for producing the information necessary for realising......This paper describes a novel method for constructing complex concrete structures from small-scale individualized elements. The method was developed through the investigation of laser cutting, folding and concrete casting in PETG plastic sheets and funicular grid shell simulations as a generator...... the construction comprised of discrete concrete elements....

  3. Research based teaching as a model for developing complex pre-cast concrete structures

    DEFF Research Database (Denmark)

    Egholm Pedersen, Ole

    2012-01-01

    This paper describes the potentials of utilising research-based teaching as a method for developing advanced concrete structures in an architectural context. A novel technique for casting concrete elements in PETG plastic is described as a body of research that formed the basis of a case in which...

  4. Rehabilitation of Collective Housing Ensembles Made of Large Precast Panels - General Aspects

    Directory of Open Access Journals (Sweden)

    Ioan Iulian VAGNER

    2013-07-01

    Full Text Available Reconsidering the attitude towards safe and energy efficient buildings makes that the forefront of a rehabilitation process be the ensuring a healthy environment, a certain quality of the indoor environment and as well as ensuring the safety of the inhabitants. The indoor environmental quality, a determining factor regarding the health and welfare of occupants of a building, is determined by the air composition (in reference to chemical pollutants, physical, biological or other nature and by the comfort (with the main components, acoustic, thermal and visual.

  5. Potential use of sewage sludge ash (SSA as a cement replacement in precast concrete blocks

    Directory of Open Access Journals (Sweden)

    Pérez-Carrión, M.

    2014-03-01

    Full Text Available The present study explored the technological feasibility of re-using sewage sludge ash (SSA as a Portland cement replacement in commercially manufactured pre cast concrete blocks. The blocks analysed were made to the guidelines laid down in Spain’s National Plan for Waste Water Treatment Plant Sludge, 2001–2006, and European Union specifications (CE marking for such products. Performance was compared in three families of blocks, with 0, 10 and 20% SSA. The findings proved that SSA is apt for pre cast concrete block manufacture and that, in addition to the economic and environmental benefits afforded, its use would improve certain of the properties of conventional block.El objetivo de esta investigación es estudiar el uso potencial de las cenizas de lodos de depuradora (CLD, como sustitución del cemento Portland en bloques de hormigón prefabricados, de forma que se pueda lograr una revalorización de este material de desecho mediante este procedimiento. La metodología utilizada en este trabajo se rige por las directrices del Plan Nacional Español de Lodos de Aguas Residuales de 2001–2006, y por las exigencias del Consejo Europeo (marcado CE, que es obligatorio para este tipo de productos. Se han utilizado dos niveles de sustitución de cemento (10% y 20%, y todos los resultados han sido referidos a las muestras control. Los resultados obtenidos muestran que es posible utilizar una sustitución parcial del cemento por CLD, en la fabricación de bloques de hormigón prefabricados, y por lo tanto, se pueden conseguir beneficios económicos y ambientales, así como la mejora de una serie de propiedades.

  6. Shear strength of match cast dry joints of precast concrete segmental bridges: proposal for Eurocode 2

    National Research Council Canada - National Science Library

    Aparicio, J. A; Ramos, G; Turmo, J

    2006-01-01

    ....Este trabajo presenta un estudio sobre el comportamientode puentes de dovelas de hormigon con llaves de cortante,centrado en el comportamiento a cortante de lasjuntas secas conjugadas en Estado Limite Ultimo...

  7. Design and construction of precast piles with stainless reinforcing steel : [summary].

    Science.gov (United States)

    2014-04-01

    In Florida, about two thirds of the 5,500 : bridges maintained by the Florida Department : of Transportation (FDOT) are set in marine : environments, making corrosion a major cause : of reduced service life. Most susceptible to this : damage are elem...

  8. Evaluation of Precast Portland Cement Concrete Panels for Airfield Pavement Repairs

    Science.gov (United States)

    2015-05-01

    ACI 318-11. Farmington Hills, MI: American Concrete Institute. AFCESA. 2008a. Testing protocol for rigid spall repair materials. ETL 08-02. Tyndall...Air Force Base, FL: Air Force Civil Engineer Support Agency. _____. 2008b. Testing protocol for polymeric spall repair materials. ETL 08-04. Tyndall

  9. Accelerated slab replacement using temporary precast panels and self-consolidating concrete.

    Science.gov (United States)

    2016-06-06

    Slab replacement is the main activity in any concrete pavement rehabilitation project. According to a survey of industry and FDOT, contractor productivity in slab replacements has been very low, ranging between 25 to 50 cu. yds. The low number of sla...

  10. Shear strength of match cast dry joints of precast concrete segmental bridges: proposal for Eurocode 2

    Directory of Open Access Journals (Sweden)

    Aparicio, J. A.

    2006-06-01

    Full Text Available This paper discusses a study on the performance of concretesegmental bridges with shear keys, focusing on theshear behaviour of castellated dry joints under ultimatelimit state conditions. The widely varying formulationused to evaluate joint shear strength were compiled,along with the experimental results published in the literatureon the subject. The various approaches were evaluatedby comparing their predictions of ultimate jointstrength to published empirical findings. The formulagiving the best prediction was adapted to the safety factorprovisions set out in Eurocode 2.Este trabajo presenta un estudio sobre el comportamientode puentes de dovelas de hormigon con llaves de cortante,centrado en el comportamiento a cortante de lasjuntas secas conjugadas en Estado Limite Ultimo. Se harealizado una exhaustiva recopilacion de la dispar formulacionexistente para evaluar la resistencia a cortante delas juntas. Se ha realizado, asimismo, una investigacionbibliografica de los resultados experimentales disponiblessobre este particular en la literatura. Los resultados recogidosen la bibliografia han sido comparados con la variadaformulacion existente para predecir la resistencia ultimade las juntas. La formula que mejor predice laresistencia ha sido identificada. Esta ha sido adaptada alformato de seguridad presente en el Eurocodigo 2.

  11. Improving the accuracy of camber predictions for precast pretensioned concrete beams : [tech transfer summary].

    Science.gov (United States)

    2015-07-01

    Implementing the recommendations of this study is expected to significantly : improve the accuracy of camber measurements and predictions and to : ultimately help reduce construction delays, improve bridge serviceability, : and decrease costs.

  12. Development of friction material by using precast prefired (pcp f) blocks

    Science.gov (United States)

    Dineshkumar, R.; Ramanamurthy, E. V. V.; Krishnapavanteja, Ch

    2017-05-01

    The braking system used to control and stop automobile system. The braking system converts the kinematic energy into heat energy by friction. The performance of the brake pad depends on composition of friction materials. The asbestos brake pads are carcinogenic nature and it makes so many health problems. The present research work is going to replacement of asbestos by new materials. The new material is made by fused ceramic materials from industrial wastage. In this study the industrial waste are recycled and conducted the suitable test to compare the performance of the new material with existing brake pad material. The wear test was conducted by pin on disc experiment. The non asbestos, nonfused, fused samples are represented by x1, x2 and x3. The new brake pad material is formed by non fused and fused ceramic materials. The brake pads are manufactured by powder compacting process.

  13. Recommendations for the use of precast deck panels at expansion joints

    Science.gov (United States)

    2008-11-01

    Prestressed concrete panels have been used by the bridge construction industry in the state of Texas for many : years to increase construction speed and improve safety and economy. At expansion joints, cast-in-place concrete : is used and requires te...

  14. Evaluation of Precast Panels for Airfield Pavement Repair. Phase 2: Results of Accelerated Pavement Testing

    Science.gov (United States)

    2013-09-01

    67 limestone. The average 28-day measured compressive strength was 5,710 psi by ASTM C39. Further details of the panel designs and their...GSL TR-13-24; Phase II 34 7 Nondestructive Testing Nondestructive tests ( NDT ) were performed to determine the structural capacity of the repaired...panel repairs using these NDT methods. Equipment used NDT were completed with a Dynatest model 8081 heavy weight deflecto- meter (HWD). The HWD

  15. Continuity diaphragm for skewed continuous span precast prestressed concrete girder bridges.

    Science.gov (United States)

    2004-10-01

    Continuity diaphragms used on skewed bents in prestressed girder bridges cause difficulties in detailing and : construction. Details for bridges with large diaphragm skew angles (>30) have not been a problem for LA DOTD. : However, as the skew angl...

  16. Rheology limits for grout materials used for precast bent cap pile pockets in hot weather.

    Science.gov (United States)

    2017-02-28

    While prefabricated bridge elements and systems (PBES) have been used for many years in Florida, The Florida Department : of Transportation (FDOT) is currently developing local specifications for PBES to ad- dress the Federal Highway : Administration...

  17. Shear and shear friction of ultra-high performance concrete bridge girders

    Science.gov (United States)

    Crane, Charles Kennan

    Ultra-High Performance Concrete (UHPC) is a new class of concrete characterized by no coarse aggregate, steel fiber reinforcement, low w/c, low permeability, compressive strength exceeding 29,000 psi (200 MPa), tensile strength ranging from 1,200 to 2,500 psi (8 to 17 MPa), and very high toughness. These properties make prestressed precast UHPC bridge girders a very attractive replacement material for steel bridge girders, particularly when site demands require a comparable beam depth to steel and a 100+ year life span is desired. In order to efficiently utilize UHPC in bridge construction, it is necessary to create new design recommendations for its use. The interface between precast UHPC girder and cast-in-place concrete decks must be characterized in order to safely use composite design methods with this new material. Due to the lack of reinforcing bars, all shear forces in UHPC girders have to be carried by the concrete and steel fibers. Current U.S. codes do not consider fiber reinforcement in calculating shear capacity. Fiber contribution must be accurately accounted for in shear equations in order to use UHPC. Casting of UHPC may cause fibers to orient in the direction of casting. If fibers are preferentially oriented, physical properties of the concrete may also become anisotropic, which must be considered in design. The current research provides new understanding of shear and shear friction phenomena in UHPC including: (1) Current AASHTO codes provide a non-conservative estimate of interface shear performance of smooth UHPC interfaces with and without interface steel. (2) Fluted interfaces can be created by impressing formliners into the surface of plastic UHPC. AASHTO and ACI codes for roughened interfaces are conservative for design of fluted UHPC interfaces.(3) A new equation for the calculation of shear capacity of UHPC girders is presented which takes into account the contribution of steel fiber reinforcement. (4) Fibers are shown to preferentially

  18. Finite element analysis of ultra-high performance concrete : modeling structural performance of an AASHTO type II girder and a 2nd generation pi-girder

    Science.gov (United States)

    2010-10-01

    Ultra-high performance concrete (UHPC) is an advanced cementitious composite material which has been developed in recent decades. When compared to more conventional cement-based concrete materials, UHPC tends to exhibit superior properties such as in...

  19. NCHRP project 20-07/task 361 : hamburg wheel-track test equipment requirements and improvements to AASHTO T 324 : research project capsule.

    Science.gov (United States)

    2015-02-01

    The Loaded Wheel Test (LWT) is a laboratory-controlled rut depth test that uses loaded wheel(s) : to apply a moving load on hot-mix and warm-mix asphalt (HMA and WMA) specimens to simulate : tra c load applied on asphalt pavements. In the 1970s He...

  20. EARTHQUAKE RESPONSE ANALYSIS OF A VIADUCT WITH HORIZONTAL FORCE DISTRIBUTED STRUCTURE USING STRONG MOTION OBSERVED DURING THE 2011 OFF THE PACIFIC COAST OF TOHOKU EARTHQUAKE

    Science.gov (United States)

    Kataoka, Shojiro; Nagaya, Kazuhiro; Yabe, Masaaki; Matsuoka, Kazunari; Kaneko, Masahiro

    Dynamic analysis is widely used for the seismic design of the bridge with horizontal force distributed structure in recent years. There is few research on dynamic analysis of such bridges using real earthquake data. In this research, we carried out dynamic analysis using accelerograms recorded during the 2011 off the Pacific coast of Tohoku earthquake (Mw9.0). The analytical earthquake response shows a good agreement with the observed response when colliding and friction forces acted between sideblocks and shoes are taken into account.

  1. Experimental Evaluation of the Failure of a Seismic Design Category - B Precast Concrete Beam-Column Connection System

    Science.gov (United States)

    2014-12-01

    setup.................................. 7  2.3.1  Overview of test specimen SDC -B...26  4.2  Observed failure modes of SDC -B .............................................................................. 26  4.3...Overall performance evaluation of SDC -B .................................................................. 38  4.4  Pseudo-static response data

  2. A precast concrete bridge bent designed to re-center after an earthquake : research report, October 2008.

    Science.gov (United States)

    2008-10-01

    In this study the post-earthquake residual displacements of reinforced concrete bridge bents were investigated. The system had mild steel that was intended to dissipate energy and an unbonded, post-tensioned tendon that was supposed to remain elastic...

  3. A precast concrete bridge bent designed to re-center after an earthquake : draft research report, August 2008.

    Science.gov (United States)

    2008-08-01

    In this study the post-earthquake residual displacements of reinforced concrete bridge bents were investigated. The system had mild steel that was intended to dissipate energy and an unbonded, post-tensioned tendon that was supposed to remain elastic...

  4. Accelerated bridge construction utilizing precast pier caps on state highway 69 over Turkey Creek, Huerfano County, CO.

    Science.gov (United States)

    2014-07-01

    The purpose of this report is to document Accelerated Bridge Construction (ABC) techniques on IBRD : (Innovative Bridge Research and Development) project 102470 for the construction of Bridge N-16-Q : on State Highway 69 over Turkey Creek. The constr...

  5. Rheology limits for grout materials used for precast bent cap pile pockets in hot weather : project summary.

    Science.gov (United States)

    2017-03-01

    The use of prefabricated bridge elements and systems (PBES) saves time and money, both for transportation agencies and the traveling public. PBES is an emphasis area in the Federal Highway Administrations Every Day Counts program in which FHWA and...

  6. Field monitoring of mechanically stabilized earth walls to investigate secondary reinforcement effects.

    Science.gov (United States)

    2015-12-01

    Mechanically stabilized earth (MSE) walls have been commonly used in highway construction. AASHTO (2007) has : detailed design procedures for such a wall system. In the current AASHTO design, only primary reinforcements are used in : relatively large...

  7. Assessment of limestone blended cements for transportation applications : final report.

    Science.gov (United States)

    2017-09-01

    This research assessed the applicability of Type IL cements satisfying AASHTO M 240 specifications for use in transportation applications in place of Type I/II cements which satisfy AASHTO M 85 specifications for construction of transportation struct...

  8. Case study: dynamic modulus characterization of naturally occurring bituminous sands for sustainable pavement applications

    CSIR Research Space (South Africa)

    Anochie-Boateng, Joseph

    2010-11-01

    Full Text Available -1 Technical Paper ISSN 1997-1400 Int. J. Pavement Res. Technol. 3(6):286-294 Copyright @ Chinese Society of Pavement Engineering Vol.3 No.6 Nov. 2010 International..., Alberta, Canada. 18. AASHTO, (2005). Standard Method of Test for Bulk Specific Gravity of Compacted Hot Mix Asphalt (HMA) Using Saturated Surface-Dry Specimens, AASHTO T 166, AASHTO, USA. 19. AASHTO, (2009). Standard Method of Test for Theoretical...

  9. 77 FR 28460 - National Standards for Traffic Control Devices; the Manual on Uniform Traffic Control Devices for...

    Science.gov (United States)

    2012-05-14

    ... to Metric Conversion. (c) AASHTO Traffic Engineering Metric Conversion Factors. (d) The standards...) AASHTO Guide to Metric Conversion, 1993; (ii) AASHTO, Traffic Engineering Metric Conversion Factors, 1993-- Addendum to the Guide to Metric Conversion, October 1993. (2) FHWA, Federal Highway Administration, 1200...

  10. Evaluation of dynamic shear rheometer tests for emulsions : [tech summary].

    Science.gov (United States)

    2014-12-01

    Currently, the Louisiana Department of Transportation and Development (DOTD) requires ductility tests at 25C according to : AASHTO T51 for emulsions, force ductility ratio at 4C, and elastic recovery at 10C according to AASHTO T300 and AASHTO :...

  11. Preparation of the implementation plan of AASHTO Mechanistic-Empirical Pavement Design Guide (M-EPDG) in Connecticut : Phase II : expanded sensitivity analysis and validation with pavement management data.

    Science.gov (United States)

    2017-02-08

    The study re-evaluates distress prediction models using the Mechanistic-Empirical Pavement Design Guide (MEPDG) and expands the sensitivity analysis to a wide range of pavement structures and soils. In addition, an extensive validation analysis of th...

  12. Implementation of Full-Width Bridge Deck Panels: A Synthesis Study

    OpenAIRE

    Versace, Jose David; Ramirez, J.A. [UNESP

    2004-01-01

    In this synthesis study, information related to full-depth precast deck systems has been collected and analyzed in order to facilitate implementation of full-depth precast deck systems in the state of Indiana. Nine full-depth precast deck systems were identified in the literature review. For girder bridges or similar, a full-depth precast, prestressed deck system (New England Region System) is recommended to be implemented. For bridges with decks spanning in the longitudinal direction, where ...

  13. Finite Element Simulation and Assessment of Single-Degree-of-Freedom Prediction Methodology for Insulated Concrete Sandwich Panels Subjected to Blast Loads

    Science.gov (United States)

    2011-02-01

    sandwich panels for blast loads. blast load; finite element modeling; large deflection behavior; load-deflection response; precast concrete ; prestressed ...of Precast/ Prestressed Concrete Structures for Blast ...............................................6 3. MODEL DEVELOPMENT AND VALIDATION...Laboratory (AFRL) and a Daniel P. Jenny Research Fellowship Grant from the Precast/ Prestressed Concrete Institute (PCI). The current technical points of

  14. Full-scale Experimental Evaluation of Partially Grouted, Minimally Reinforced Concrete Masonry Unit (CMU) Walls Against Blast Demands

    Science.gov (United States)

    2010-11-30

    research under this program was “to develop blast protection data for concrete building products (e.g. insulated form walls, precast/ prestressed panels...Association (PCA), Precast/ prestressed Concrete Institute (PCI), Tilt-Up Concrete Association (TCA), Insulating Concrete Form Association (ICFA), Concrete ...Ready Mixed Concrete Association PDC Protective Design Center PCA Portland Cement Association PCI Precast/ prestressed Concrete Institute psi

  15. Research Article

    African Journals Online (AJOL)

    2016-06-11

    Jun 11, 2016 ... g this method in design of existing connections between precast co ural systems; precast ... According to the type of precast structure, we can use of several design methods which one of them is the .... transfer from one-way slabs,they are providing the resistance of building against seismic loads.

  16. Deflections and Natural Frequencies as Parameters for Structural Health Monitoring : The Effect of Fatigue and Corrosion on the Deflections and the Natural Frequencies of Reinforced Concrete Beams

    NARCIS (Netherlands)

    Veerman, R.P.

    2017-01-01

    The Dutch road infrastructure contains a large number of concrete bridges and viaducts. Malfunction of these bridges and viaducts has large financial consequences. To avoid malfunctions of bridges, bridges need to be inspected frequently and actions should be taken when required. The reliability of

  17. 25 CFR Appendix B to Subpart D - Design Standards for the IRR Program

    Science.gov (United States)

    2010-04-01

    ... Transportation Landscape and Environmental Design. 3. AASHTO Roadside Design Guide, latest edition. 4. AASHTO... 25 Indians 1 2010-04-01 2010-04-01 false Design Standards for the IRR Program B Appendix B to... ROADS PROGRAM Planning, Design, and Construction of Indian Reservation Roads Program Facilities Pt. 170...

  18. 23 CFR 655.601 - Purpose.

    Science.gov (United States)

    2010-04-01

    ... to Metric Conversion, AASHTO, 1993. This publication is incorporated by reference in accordance with... 20001. (c) Traffic Engineering Metric Conversion Factors, 1993—Addendum to the Guide to Metric Conversion, AASHTO, October 1993. This publication is incorporated by reference in accordance with 5 U.S.C...

  19. Railing systems for use on timber deck bridges

    Science.gov (United States)

    Ronald K. Faller; Michael A. Ritter; Barry T. Rosson; Sheila R. Duwadi

    1999-01-01

    Bridge railing systems in the United States have historically been designed based on static load criteria given in the AASHTO Standard Specifications for Highway Bridges. In the past decade, full-scale vehicle crash testing has been recognized as a more appropriate and reliable method of evaluating bridge railing acceptability. In 1989. AASHTO published the Guide...

  20. assessment of assessment of bagasse ash bagasse ash bagasse ...

    African Journals Online (AJOL)

    eobe

    Clay material of Group A-6 using AASHTO classification and inorganic clay material. 6 using AASHTO ... Construction Industry Research and Information .... The chemical composition of the Bagasse ash (BA) was determined at the Center for Energy Research and Training. (CERT), A. B. U. Zaria using the method of Energy.

  1. assessment of assessment of bagasse ash bagasse ash bagasse ...

    African Journals Online (AJOL)

    eobe

    Clay material of Group A-6 using AASHTO classification and inorganic clay material. 6 using AASHTO classification and ... medium plasticity CL according to Unified Soil Classification System (USCS). The specific gravity of the soil .... alteration to its physical, chemical, biological or radiological integrity resulting from ...

  2. 23 CFR 637.209 - Laboratory and sampling and testing personnel qualifications.

    Science.gov (United States)

    2010-04-01

    ... ENGINEERING AND TRAFFIC OPERATIONS CONSTRUCTION INSPECTION AND APPROVAL Quality Assurance Procedures for... accredited by the AASHTO Accreditation Program or a comparable laboratory accreditation program approved by... testing shall be accredited in the testing to be performed by the AASHTO Accreditation Program or a...

  3. Assessment of high early strength limestone blended cement for next generation transportation structures : final report.

    Science.gov (United States)

    2016-12-01

    This research on Type IL cements for high early strength concretes demonstrated that Type IL cements satisfying AASHTO M 240 specifications may be used in place of Type I/II cements which satisfy AASHTO M 85 specifications for construction of transpo...

  4. Performance of portland limestone cements : cements designed to be more sustainable that include up to 15% limestone addition.

    Science.gov (United States)

    2013-11-01

    In 2009, ASTM and AASHTO permitted the use of up to 5% interground limestone in ordinary portland cement (OPC) as a part of ASTM : C150/AASHTO M85. When this project was initiated a new proposal was being discussed that would enable up to 15% intergr...

  5. Miscellaneous wood structures

    Science.gov (United States)

    Michael A. Ritter; Keith F. Faherty

    1999-01-01

    This section addresses the design of two types of glulam timber bridges : beam bridges with transverse decks and longitudinal glulam deck (slab) bridges. The material presented in the section is based on the 1992 edition of the AASHTO Standard Specifications for Highway Bridges (AASHTO specifications), including interim specifications through 1993. When specific design...

  6. Some geotechnical properties of a cement-stabilized granite-gneiss ...

    African Journals Online (AJOL)

    The influence of cement stabilization on the unconfined compressive strengths of the soil was found to be strong upon compaction at both the West African and the modified AASHTO levels. However, soil samples compacted at the modified AASHTO level without adding cement exhibited much higher strengths than those ...

  7. Evaluation of Shear Tie Connectors for Use in Insulated Concrete Sandwich Panels

    Science.gov (United States)

    2009-12-01

    of non-load bearing precast/ prestressed or tilt-up concrete sandwich wall panels (WP) are examined. These components are used extensively in modern... prestress wall panels, precast wall panels, tilt-up wall panels, concrete insulted wall systems U U U UU 37 Paul Sheppard Reset i Table of...illustrate this concept, the blast resistances of non-load bearing precast/ prestressed or tilt-up concrete sandwich wall panels were examined. These

  8. Renovation of Large-Panel Buildings in Context of Urban Renewal/ Remonty Budynków Wielkopłytowych, Jako Element Rewitalizacji Miast

    National Research Council Canada - National Science Library

    Wiesław Ligęza

    2015-01-01

    The article presents issues connected with renovating multi-storey precast concrete buildings, resulting from the consequences of construction defects occurring over the course of the building process...

  9. Sadhana | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Sadhana. İsmail Yüksek. Articles written in Sadhana. Volume 31 Issue 1 February 2006 pp 9-20. Natural frequencies of a flat viaduct road part simply supported on two ends · İsmail Yüksek Ahmet Çelık Kayhan Gülez · More Details Abstract Fulltext PDF. Viaduct roads have wide application in big cities with ...

  10. Full-scale Blast Test Response of Partially Grouted Masonry Walls

    Science.gov (United States)

    2011-01-01

    walls, precast/ prestressed panels, tilt-up panels, masonry components, autoclaved concrete components, cast-in-place forming systems, etc...included: the Portland Cement Association (PCA), Precast/ prestressed Concrete Institute (PCI), Tilt-Up Concrete Association (TCA), Insulating Concrete ...collaborative research program among the Air Force Research Laboratory (AFRL), the Portland Cement Association (PCA), and the National Concrete Masonry

  11. application of yield line the ion of yield line theory in pre ion of yield

    African Journals Online (AJOL)

    User

    Analysis of precast waffle slabs have ysis of precast waffle slabs have unanalyzed. T unanalyzed. This has led to cracks or his has led to cracks or. This paper proposed the use of. This paper proposed the use of yield line theory yield line theory develop a computer program called YLRGT a computer program called YLRGT.

  12. Influence of concrete slabs on lateral torsional buckling of steel beams

    NARCIS (Netherlands)

    Maljaars, J.; Snijder, H.H.; Hoenderkamp, J.C.D.

    2007-01-01

    The use of pre-cast concrete floor slabs in steel framed structures is quite common. In the de-sign of the steel beams, the lateral restraining effect of the pre-cast concrete slab is normally safely neglected. However, the concrete slab will provide some horizontal restraint, even without special

  13. Research Article

    African Journals Online (AJOL)

    2016-06-11

    Jun 11, 2016 ... Journal of Fundamental and Applied Scienc. ISSN 1112-9867 ... g this method in design of existing connections between precast co ural systems ... veral advantages of precast concrete structures, such as reducing ti ducing the ... Beam/column systems (a) single-storey columns (b) multi-storey columns. 3.

  14. 29 CFR 1926.502 - Fall protection systems criteria and practices.

    Science.gov (United States)

    2010-07-01

    ... between posts, shall be not more than 19 inches (48 cm) apart. (iv) Other structural members (such as... all top rails and midrails shall not overhang the terminal posts, except where such overhang does not... when erecting precast concrete members. (ii) When erecting precast concrete members, the control line...

  15. Survey of welding processes.

    Science.gov (United States)

    2003-07-01

    The current KYTC SPECIAL PROVISION NO. 4 WELDING STEEL BRIDGES prohibits the use of welding processes other than shielded metal arc welding (SMAW) and submerged arc welding (SAW). Nationally, bridge welding is codified under ANSI/AASHTO/AWS D1....

  16. Route 139 rehabilitation: Pulaski Skyway contract 2 : technical brief.

    Science.gov (United States)

    2017-06-01

    This study addressed the need for an aesthetically pleasing historic concrete balustrade design alternative for the Pulaski Skyway in Jersey City, Hudson County. In this study, a crashworthy design was developed according to AASHTO Section 13 specifi...

  17. Design and performance verification of UHPC piles for deep foundations.

    Science.gov (United States)

    2008-11-01

    The strategic plan for bridge engineering issued by AASHTO in 2005 identified extending the service life and optimizing structural : systems of bridges in the United States as two grand challenges in bridge engineering, with the objective of producin...

  18. Determination of mechanical properties for cement-treated aggregate base : final report.

    Science.gov (United States)

    2017-06-01

    The Virginia Department of Transportation (VDOT) currently follows pavement design procedures for all new and rehabilitated pavements based on the 1993 AASHTO Guide for Design of Pavement Structures. VDOTs Materials Division is in the process of i...

  19. Assessment of non-destructive testing technologies for quality control/quality assurance of asphalt mixtures.

    Science.gov (United States)

    2015-03-01

    Asphalt pavements suffer various failures due to insufficient quality within their design lives. The American Association of State : Highway and Transportation Officials (AASHTO) Mechanistic-Empirical Pavement Design Guide (MEPDG) has been proposed :...

  20. Advanced bridge safety initiative, task 1 : development of improved analytical load rating procedures for flat-slab concrete bridges - a thesis and guidelines.

    Science.gov (United States)

    2010-01-01

    Current AASHTO provisions for the conventional load rating of flat slab bridges rely on the equivalent strip method : of analysis for determining live load effects, this is generally regarded as overly conservative by many professional : engineers. A...

  1. Rock mass classification system : transition from RMR to GSI.

    Science.gov (United States)

    2013-11-01

    The AASHTO LRFD Bridge Design Specifications is expected to replace the rock mass rating : (RMR) system with the Geological Strength Index (GSI) system for classifying and estimating : engineering properties of rock masses. This transition is motivat...

  2. Bottom flange reinforcement in NU I-girders.

    Science.gov (United States)

    2010-08-01

    "The 1996 edition of AASHTO Standard Specifications for Highway Bridges stated that nominal confinement reinforcement be placed to enclose prestressing steel in the bottom flange of bridge girders from girder ends to at least a distance eq changed th...

  3. High skew link slab bridge system with deck sliding over backwall or backwall sliding over abutments : appendices.

    Science.gov (United States)

    2011-09-01

    AASHTO LRFD (2010) requires combined live and thermal load effects for the service : limit state design. The Design Procedure described in the appendix will follow the : rationale developed by Ulku et al. (2009). Link slab design moments are calculat...

  4. Advanced bridge safety initiative : recommended practices for live load testing of existing flat-slab concrete bridges - task 5.

    Science.gov (United States)

    2012-12-01

    Current AASHTO provisions for load rating flat-slab concrete bridges use the equivalent strip : width method, which is regarded as overly conservative compared to more advanced analysis : methods and field live load testing. It has been shown that li...

  5. Overload truck wheel load distribution on bridge decks.

    Science.gov (United States)

    2009-04-01

    There is a need to accurately analyze the load effects on bridge decks from permitted overload trucks on : Michigans roads. The AASHTO Standard Specifications for Highway Bridges, 17th edition, provides a : distribution width of live loads when re...

  6. Geotechnical design manual : research project capsule.

    Science.gov (United States)

    2016-11-01

    The Louisiana Department of Transportation and Development (DOTD), through its Pavement : and Geotechnical Design section, has developed policies and procedures over the years utilizing its own methods and those incorporated from others (AASHTO, FHWA...

  7. Value engineering and cost effectiveness of various fiber reinforced polymer (FRP) repair systems.

    Science.gov (United States)

    2006-06-01

    Seventeen 40 year old C-Channel type prestressed concrete bridge girders and one impact damaged AASHTO : Type II prestressed concrete girder were tested under static and fatigue loading to determine the cost-effectiveness : and value engineering aspe...

  8. Development of risk models for Florida's bridge management system.

    Science.gov (United States)

    2013-06-01

    Florida Department of Transportation (FDOT) has been actively implementing the American Association of State Highway Transportation Officials (AASHTO) Pontis Bridge Management System (BMS), recently renamed AASHTOWare Bridge Management (BrM), to supp...

  9. Seismic Design Considerations : Volume I, Technical Approaches and Results; Volume II, Appendices II-VIII

    Science.gov (United States)

    2012-03-01

    NJDOT has adopted AASHTO Guide Specifications for LRFD Seismic Bridge Design approved by the Highway : Subcommittee on Bridges and Structures in 2007. The main objective of research presented in this report has : been to resolve following issue...

  10. Influence of the new LRFD seismic guidelines on the design of bridges in Virginia.

    Science.gov (United States)

    2004-01-01

    The Virginia Department of Transportation is currently using the AASHTO Standard Specifications for Highway Bridges, with some modifications, for its seismic highway bridge design. In April 2001, the Recommended LRFD Guidelines for the Seismic Design...

  11. Effects of increasing the allowable compressive stress at release on the shear strength of prestressed concrete girders.

    Science.gov (United States)

    2008-09-01

    In recent years, several research projects have been conducted to study the feasibility of increasing the allowable : compressive stress in concrete at prestress transfer, currently defined as 0.60f'ci in the AASHTO LRFD Bridge : Design Specification...

  12. Modeling the response of fracture critical steel box-girder bridges.

    Science.gov (United States)

    2010-02-01

    Bridges that are classified as fracture critical by AASHTO require more frequent inspections than other types of : bridges, resulting in greater costs for their maintenance. Several historical events have shown, however, that : severe damage can occu...

  13. Evidence-based decision making : developing a knowledge base for successful program outcomes in transportation asset management.

    Science.gov (United States)

    2015-12-01

    MAP-21 and AASHTOs framework for transportation asset management (TAM) offer opportunities to use more : rigorous approaches to collect and apply evidence within a TAM context. This report documents the results of a study : funded by the Georgia D...

  14. Surface resistivity test evaluation as an indicator of the chloride permeability of concrete.

    Science.gov (United States)

    2012-12-01

    Many agencies have adopted the standard tests for electrical : indication of concretes ability to resist chloride ion penetration : (AASHTO T 277 and ASTM C1202), commonly known as the rapid : chloride permeability test (RCPT), in their specificat...

  15. Survey of state funding for public transportation 2010

    Science.gov (United States)

    2010-07-01

    The AASHTO Standing Committee on Public Transportation is pleased to release the Survey of State : Funding for Public Transportation. The survey results reflect Fiscal Year 2008 data. This annual report : provides a snapshot of state-by-state investm...

  16. Survey of state funding for public transportation 2007

    Science.gov (United States)

    2008-12-01

    The AASHTO Standing Committee on Public Transportation is pleased to release the Survey of State Funding : for Public Transportation. The survey results reflect Fiscal Year 2007 data. This annual report provides a : snapshot of state-by-state investm...

  17. Evaluation of dynamic shear rheometer tests for emulsions : research project capsule.

    Science.gov (United States)

    2010-10-01

    Currently, the Louisiana Department of Transportation and Development (LADOTD) : requires ductility tests at 25C according to AASHTO T51 for emulsions and two : other tests, namely force ductility ratio at 4C and elastic recovery at 10C : accor...

  18. Evaluation of dynamic shear rheometer tests for emulsions.

    Science.gov (United States)

    2014-12-01

    DSR-based rheological tests of 20 different : asphalt emulsion residues were : performed and relationships : with elastic recovery (A : ASHTO : T301) and force ductility (AASHTO T : 300) were investigated. In stra : in sweep test from 2% to 52% : , i...

  19. Enhancement of the FDOT's project level and network level bridge management analysis tools

    Science.gov (United States)

    2011-02-01

    Over several years, the Florida Department of Transportation (FDOT) has been implementing the AASHTO Pontis Bridge Management System to support network-level and project-level decision making in the headquarters and district offices. Pontis is an int...

  20. Journal of the Ghana Institution of Engineers - Vol 2, No 1 (2004)

    African Journals Online (AJOL)

    The use of deferential equation in problems solving applied to reinforced precast and prestressed concrete structures · EMAIL FULL TEXT EMAIL FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. G Sossou, 35-40 ...

  1. Calibration of Resistance Factors Needed in the LRFD Design of Driven Piles

    Science.gov (United States)

    2009-05-01

    This research project presents the calibration of resistance factors for the Load and Resistance Factor Design (LRFD) method of driven : piles driven into Louisiana soils based on reliability theory. Fifty-three square Precast-Prestressed-Concrete (P...

  2. Guide to cement-based integrated pavement solutions.

    Science.gov (United States)

    2011-08-01

    This guide provides a clear, concise, and cohesive presentation of cement-bound materials options for 10 : specific engineering pavement applications: new concrete pavements, concrete overlays, pervious concrete, : precast pavements, roller-compacted...

  3. New Whole-House Solutions Case Study: S&A Homes, Pittsburgh, Pennsylvania

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2013-09-01

    This builder worked with IBACOS to design urban infill HERS-51 homes with compact duct layout in conditioned space, foam insulated precast concrete foundations, high-efficiency HVAC, and tankless water heaters

  4. 0-6722 : spread prestressed concrete slab beam bridges.

    Science.gov (United States)

    2014-08-01

    The Texas Department of Transportation uses : precast prestressed concrete slab beam bridges for : shorter-span bridges of approximately 3050 ft in : length. Conventional slab beam bridges have slab : beams placed immediately adjacent to one anoth...

  5. Theoretical and field experimental evaluation of skewed modular slab bridges : [research summary].

    Science.gov (United States)

    2012-12-01

    Adjacent precast, prestressed concrete multi-beam bridges have become more : prevalent due to their rapid construction time and cost effectiveness. Over the : years, various adjustments and refinements have been made to the design of : these bridges ...

  6. Forensic investigation of two voided slab bridges in the Virginia Department of Transportation's Richmond District.

    Science.gov (United States)

    2017-06-01

    The precast prestressed concrete voided slab structure is a popular bridge design because of its rapid construction and cost : savings in terms of eliminating formwork at the jobsite. However, the longitudinal shear transfer mechanism often fails, le...

  7. Development and validation of a sensor-based health monitoring model for the Parkview Bridge deck.

    Science.gov (United States)

    2012-01-31

    Accelerated bridge construction (ABC) using full-depth precast deck panels is an innovative technique that brings all : the benefits listed under ABC to full fruition. However, this technique needs to be evaluated and the performance of : the bridge ...

  8. Development and validation of a sensor-based health monitoring model for the Parkview Bridge deck : [appendices].

    Science.gov (United States)

    2012-01-31

    Accelerated bridge construction (ABC) using full-depth precast deck panels is an innovative technique that brings all the benefits listed under ABC to full fruition. However, this technique needs to be evaluated and the performance of the bridge need...

  9. Use of solar energy for heliothermal treatment of concretes on the basis of alkali cements

    National Research Council Canada - National Science Library

    Aymenov, Zh.T; Sarsenbayev, B.K; Sarsenbayev, N.B; Aldiyarov, Zh.A

    2016-01-01

    .... Application of helioforms with various translucent and solar perceptive coatings can be considered as one of the directions of solar energy application for thermal treatment of precast concrete. Heliothermа...

  10. 75 FR 47905 - Cranes and Derricks in Construction

    Science.gov (United States)

    2010-08-09

    ... Industry,'' 132 Journal of Construction Engineering and Management 901 (Sept. 2006) (ID OSHA-2007-0066-0012... workers to the hospital. The launching gantry was being used to erect pre-cast concrete segments span by...

  11. Experimental validation of bracing recommendations for long-span concrete girders : final report.

    Science.gov (United States)

    2012-12-01

    During bridge construction, flexible support conditions provided by steel-reinforced neoprene bearing pads supporting precast, prestressed concrete girders may allow the girders to become unstable, rolling about an axis parallel to the span of the gi...

  12. The future of rapid bridge deck replacement.

    Science.gov (United States)

    2015-06-01

    Replacing aging, deteriorated infrastructure often requires road closures and traffic detours which impose : inconvenience and delay on commerce and members of the motoring public. Accelerated bridge construction : techniques often use precast member...

  13. Design aids of NU I-girders bridges.

    Science.gov (United States)

    2010-05-01

    Precast prestressed concrete I-Girder bridges have become the most dominant bridge system in the United States. In the early design : stages, preliminary design becomes a vital first step in designing an economical bridge. Within the state of Nebrask...

  14. Self-consolidating concrete for prestressed applications - phase II : bridge construction and in-place performance.

    Science.gov (United States)

    2015-04-01

    Prior to statewide acceptance of self-consolidating concrete (SCC) in precast, prestressed bridge member : production, the Alabama Department of Transportation sponsored an investigation of the material to be : performed by the Auburn University High...

  15. Forensic testing of a double tee bridge.

    Science.gov (United States)

    2014-12-01

    This report describes an investigation to quantify the behavior of precast, prestressed concrete double-tee bridge : girders made with lightweight concrete. As part of the investigation, three bridge girders were salvaged from a : decommissioned brid...

  16. Continuous prestressed concrete girder bridges, volume 2 : analysis, testing, and recommendations.

    Science.gov (United States)

    2016-12-01

    The Texas Department of Transportation designs typical highway bridge structures as simple span systems using : standard precast, pretensioned girders. Spans are limited to about 150 ft due to weight and length restrictions on : transporting the prec...

  17. Self-Consolidating Concrete for Prestressed Bridge Girders : Research Brief

    Science.gov (United States)

    2017-08-01

    Self-consolidating concrete (SCC) is commonly used as an alternative to conventional concrete (CC) in precast, prestressed concrete (PSC) bridge girders. The high strength, highly workable mixture can flow through dense reinforcement to fill formwork...

  18. Continuous prestressed concrete girder bridges volume 1 : literature review and preliminary designs.

    Science.gov (United States)

    2012-06-01

    The Texas Department of Transportation (TxDOT) is currently designing typical highway bridge structures as simply supported using standard precast, pretensioned girders. TxDOT is interested in developing additional economical design alternatives for ...

  19. Self-consolidating concrete for prestressed applications - phase I : girder fabrication and pre-erection performance.

    Science.gov (United States)

    2015-04-01

    Prior to statewide acceptance of self-consolidating concrete (SCC) in precast, prestressed bridge member production, the Alabama Department of Transportation sponsored an investigation of the material to be performed by the Auburn University Highway ...

  20. Behavior of Pile to Bent Cap Connections Subjected to Seismic Forces

    Science.gov (United States)

    2012-06-01

    Currently the South Carolina Department of Transportation employs a detail of a plain pile embedment for the : connection between precast prestressed piles and cast-in-place bent caps. This connection has proved beneficial in terms : of time and cost...

  1. Design, construction, and field testing of an ultra high performance concrete pi-girder bridge.

    Science.gov (United States)

    2011-01-01

    The Jakway Park Bridge in Buchanan County, Iowa is the first bridge constructed with a new prestesssed girder system composed of : precast Ultra-High Performance Concrete (UHPC). These girders employ an integral deck to facilitate construction and ar...

  2. Bridge management system for the Western Cape provincial government, South Africa: implementation and utilization

    CSIR Research Space (South Africa)

    Nell, AJ

    2008-10-01

    Full Text Available Examples of structural repairs a) repairs to culvert wing walls, abutment walls as well as deck slab, b) replacement of existing steel bridge handrails with precast concrete rails, c) repairs to bridge abutment by means of externally reinforced concrete... general problem of reinforcement corrosion. New precast reinforced concrete railings were proposed in instances were vandalism had occurred; • Bearings were generally in a good condition; • Selected road safety elements were also identified for repair...

  3. Prefab Apartment Blocks in Singapore

    DEFF Research Database (Denmark)

    Kjærbye, Per Oluf H

    1997-01-01

    Skaarup & Jespersen, Architects and Planners, has designed and built 625 housing units for Housing Development Board in Singapore after an international competition.Experiences from the Danish precast systems have been used.......Skaarup & Jespersen, Architects and Planners, has designed and built 625 housing units for Housing Development Board in Singapore after an international competition.Experiences from the Danish precast systems have been used....

  4. Analytical Method Used to Calculate Pile Foundations with the Widening Up on a Horizontal Static Impact

    Science.gov (United States)

    Kupchikova, N. V.; Kurbatskiy, E. N.

    2017-11-01

    This paper presents a methodology for the analytical research solutions for the work pile foundations with surface broadening and inclined side faces in the ground array, based on the properties of Fourier transform of finite functions. The comparative analysis of the calculation results using the suggested method for prismatic piles, piles with surface broadening prismatic with precast piles and end walls with precast wedges on the surface is described.

  5. If Only it Could Speak

    DEFF Research Database (Denmark)

    Jensen, Ole B.

    2012-01-01

    cleaves its way on the north-south trajectory through the city via raised ramps and elevated sections and carries about 110,000 vehicles a day. One of these sections, the Alaskan Way Viaduct, was built on old seawall structures and created a buffer between the city and the sea at Elliott Bay. The Alaskan...... Way Viaduct, colloquially known as the “Seawall,” was opened on April 4, 1953 and extensively damaged by an earthquake in 2001. The subsequent debate concerning plans for its reconstruction serves as a lens for understanding the complex relationship that exists between human and non-human elements...

  6. Hormigón liviano de alto desempeño - una comparación entre pérdidas de pretensado reales y estimadas por los códigos de diseño High performance lightweight concrete - a comparison between actual prestress losses and design code estimates

    Directory of Open Access Journals (Sweden)

    Mauricio López

    2007-04-01

    Full Text Available Dos mezclas de hormigón liviano de alto desempeño (HLAD con resistencias a compresión de 55 MPa y 69 MPa fueron desarrolladas. El peso unitario de los hormigones fue 1855 y 1890 kg/m, respectivamente. Creep, retracción y pérdidas de pretensado fueron investigadas en 36 probetas cilíndricas y en cuatro vigas pretensadas AASHTO tipo II. Las pérdidas de pretensado medidas en las vigas AASHTO tipo II fabricadas con HLAD fueron menores que las estimadas con los métodos descritos en los códigos AASHTO, PCI y ACI-209, lo que significa que los códigos de diseño dan estimaciónes conservadoras de las pérdidas de pretensado en este nuevo hormigón. Basados en los datos experimentales, las pérdidas finales de pretensado fueron estimadas como un 14.3 y 9.6% de la carga inicial aplicada para las vigas hechas con HLAD de 55 y 69 MPa, respectivamenteTwo different high performance lightweight concretes (HPLC with strengths of 55 and 69 MPa were developed. They had an air-dry unit weight of 1855 and 1890 kg/m³, respectively. Creep, shrinkage and prestress losses were investigated on 36 cylinder specimens and on four AASHTO Type II girders. Prestress losses measured on the AASHTO Type II girders made with HPLC were less than those predicted using AASHTO, PCI and ACI-209 methods which means that the design codes give conservative estimates of the actual prestress losses of this new concrete. Based on experimental data, final, total prestress losses were estimated to be 14.3 and 9.6% of the initial prestressing force for the 55-MPa and 69-MPa HPLC, respectively

  7. S¯adhan¯a Vol. 31, 2005 Subject Index

    Indian Academy of Sciences (India)

    Automatic recognition. New method for a person identification sys- tem. 259. Bearing damage. Detection of bearing defects in three-phase induction motors using Park's transform and radical basis function neural networks 235. Bending vibrations. Natural frequencies of a flat viaduct road part simply supported on two ends.

  8. Experimental evaluation of the dynamic response of two sections of the HSL in the Netherlands

    NARCIS (Netherlands)

    Galanti, F.M.B.; Maijenburg, A.T.G.

    2005-01-01

    Vibrations measurements using a falling weight have been carried out on two sections of the new high speed railway line in the Netherlands. The two sections concern a set-tlement free plate and a viaduct. The purpose of the tests was to validate finite element models used to predict the dynamic

  9. Extinction (12) 1206 (FA) Extremum problem (9) 907 (SA) Fair game ...

    Indian Academy of Sciences (India)

    Admin

    Gambling (1) 66 (GA). Gamma ray astronomy (10) 985 (GA). Garabit Viaduct (9) 840 (GA). Garuga pinnata Roxb. ... Kepler's laws (12) 1153 (GA). Kodaikanal Observatory (11) 1032 (GA). Kolmogorov–Sinai entropy (8) 761 (GA) .... Semicircle law (10) 970 (GA). Semi-classical limit (10) 934 (SA). Sexual selection (2) 102 (GA).

  10. Non-Linear Finite Element Analyses of Existing Reinforced Concrete Bridge Beams

    NARCIS (Netherlands)

    Belletti, B.; Damoni, C.; Hendriks, M.A.N.

    2013-01-01

    Three years ago, the Dutch Ministry of Infrastructure and the Environment initiated a project to re-evaluate the carrying capacity of existing bridges and viaducts (e.g. reinforced and pre-stressed concrete beams and slabs). Due to the increase of traffic and the reallocation of emergency lanes to

  11. Traffic load model based on weigh in motion measurements

    NARCIS (Netherlands)

    Steenbergen, R.D.J.M.; Morales Napoles, O.

    2012-01-01

    The assessment of the structural safety of existing bridges and viaducts becomes increasingly important in many countries. Within the actions applied to the bridges, the traffic load is, in general, the most significant variable action to be considered when the ultimate limit states are under

  12. Electrical pulses protect concrete

    NARCIS (Netherlands)

    Koleva, D.; Fraaij, A.; Van Kasteren, J.

    2006-01-01

    Even concrete is not as hard as it looks. Sea water, salt on icy roads, and indirectly even carbon dioxide from the air can corrode the steel of the reinforcing bars and so threaten the strength and integrity of a bridge pier, jetty, or viaduct. Dessi Koleva, a chemical engineer from Bulgaria, spent

  13. Performance evaluation of corrosion-affected reinforced concrete ...

    Indian Academy of Sciences (India)

    ... a case study of a severely distressed beam of the Rocky Point Viaduct. The results obtained using the proposed approach are compared with those obtained using conventional MC model. It is noted that the use of MC with fuzzy states leads to conservative decision making for the problem considered in the case study.

  14. Evaluation of repeatability of Kansas test method KT-73, "density, absorption and voids in hardened concrete," boil test.

    Science.gov (United States)

    2015-06-01

    For years, the Kansas Department of Transportation (KDOT) and concrete producers in the state have used a : Rapid Chloride Test for concrete cylinders, AASHTO T277. This test has been thought of as an appropriate quality : control test to evaluate pe...

  15. Current developments in performance testing of bituminous emulsions used in chip seals

    CSIR Research Space (South Africa)

    Johannes, PT

    2015-08-01

    Full Text Available or pseudoplastic liquids, i.e. their viscosity depends on magnitude and duration of shearing [10]. The Rotational Viscometer (RV) similar to that specified in AASHTO TP 48 and ASTM D4402 has been reported to be suitable test for evaluating viscosity of shear...

  16. Crashworthy railing for timber bridges

    Science.gov (United States)

    Michael A. Ritter; Ronald K. Faller; Sheila Rimal. Duwadi

    1999-01-01

    Bridge railing systems in the United States have historically beers designed based on static load criteria given in the American Association of State Highway and Transportation 0fficials (AASHTO) Standard Specifications for Highway Bridges. In the past decade, full-scale vehicle crash testing has been recognized as a more appropriate and reliable method of evaluating...

  17. Laboratory characterization of materials & data management for Ohio-SHRP Projects (U.S. 23) : research implementation plan.

    Science.gov (United States)

    2006-02-01

    Highway design engineers in the U.S. have been relying on the 1986-1993 American Association of State Highway : and Transportation Officials (AASHTO) Design Guide, which is based on the many empirical elements obtained in : the 40-year old AASTHO Roa...

  18. Laboratory characterization of materials & data management for Ohio-SHRP Projects (U.S. 23) : executive summary.

    Science.gov (United States)

    2002-01-01

    Highway design engineers in the U.S. have been relying on the 1986-1993 American Association : of State Highway and Transportation Officials (AASHTO) Design Guide, which is based on the : many empirical elements obtained in the 40-year old AASHO Road...

  19. Finite element simulation of truck impacts on highway bridge piers : final report.

    Science.gov (United States)

    2016-04-01

    Recent studies show that the dynamic forces because of truck impacts may be significantly higher than the : 600kips force recommended by the AASHTO. Hence, there is a need to carry out detailed investigations : on vehicular-bridge collision for a rel...

  20. Using expert opinion to quantify accuracy and reliability of nondestructive evaluation on bridges.

    Science.gov (United States)

    2015-08-01

    Bridge inspection is an important phase in bridge management. In 2009, a joint American Society of Civil : Engineers Structural Engineering Institute and AASHTO Ad-Hoc group was created to identify the issues : in bridge safety and to study current b...

  1. application of multilinear regression analysis in modeling of soil ...

    African Journals Online (AJOL)

    Windows User

    shown in Table 6. Basically, there are two soil classification systems often use for engineering purposes. The Unified Soil Classification System (USCS) which is basically, used for virtually all geotechnical engineering work except road construction and highway, but the AASHTO soil classification system is used for both.

  2. Guidelines for Implementing NCHRP 1-37A M-E Design Procedures in Ohio : Volume 3 -- Sensitivity Analysis

    Science.gov (United States)

    2009-11-01

    The new Mechanistic-Empirical Pavement Design Guide (NCHRP 1-37A and 1-40D) is based on fundamental engineering principles and is far more comprehensive than the current empirical AASHTO Design Guide developed for conditions more than 40 years previo...

  3. Designing timber bridge superstructures : a comparison of U.S. and Canadian bridge codes.

    Science.gov (United States)

    James Scott Groenier; James P. Wacker

    2008-01-01

    Several changes relating to timber bridges have been incorporated into the AASHTO-LRFD Bridge Design Specifications recently. In addition, the Federal Highway Administration is strongly encouraging an LRFD-based design approach for all new bridges in the United States. The Bridge Design Code in Canada was one of the first to adopt the limit states design philosophy,...

  4. Public–private partnership conceptual framework and models for the ...

    African Journals Online (AJOL)

    Reviewed reports relating to water services infrastructure needs and funding in the Gauteng and Limpopo Provinces, ..... will continue with research and development related work and further support for 2 to 3 years after .... TRANSPORTATION OFFICIALS) (1995) Innovative Transport. Financing. AASHTO, Washington, DC.

  5. Evaluation of the Hamburg Rut Tester and Moisture Induced Stress Test (MIST) for field control of hot mix asphalt (HMA) in Oklahoma : final report.

    Science.gov (United States)

    2013-03-01

    This report covers the evaluation of the Hamburg Loaded Wheel Rut Tester (OHD L-55) and the : Moisture Induced Stress Tester (MIST) for field control of Oklahoma HMA mixtures. OHD L-55 : was evaluated as a possible replacement for AASHTO T 283 and fo...

  6. Design of mechanically stabilized earth wall connections and end of walls subjected to seismic loads.

    Science.gov (United States)

    2014-01-01

    The 4th Edition of the AASHTO LRFD Bridge Design Specifications requires all states to design for a 1,000- : year return period earthquake, as opposed to earlier editions 500-year return period. In response to this : requirement, the Colorado Depa...

  7. High strength reinforcing steel bars : low-cycle fatigue behavior : final report - part B.

    Science.gov (United States)

    2017-03-01

    High-strength steel (HSS) reinforcing steel, specifically ASTM A706 Grade 80 (550), is now permitted by the AASHTO LRFD Bridge Design Specifications for use in reinforced concrete bridge components in non-seismic regions. Using Grade 80 (550) reinfor...

  8. High strength reinforcing steel bars : low cycle fatigue behavior : final report - part B.

    Science.gov (United States)

    2017-03-01

    High-strength steel (HSS) reinforcing steel, specifically ASTM A706 Grade 80 (550), is now permitted by the AASHTO LRFD Bridge Design Specifications for use in reinforced concrete bridge components in non-seismic regions. Using Grade 80 (550) reinfor...

  9. High strength reinforcing steel bars : concrete shear friction interface : final report : Part A.

    Science.gov (United States)

    2017-03-01

    High-strength steel (HSS) reinforcement, specifically ASTM A706 Grade 80 (550), is now permitted by the AASHTO LRFD Bridge Design Specifications for use in reinforced concrete bridge components in non-seismic regions. Using Grade 80 (550) steel reinf...

  10. 23 CFR 652.13 - Design and construction criteria.

    Science.gov (United States)

    2010-04-01

    ... PEDESTRIAN AND BICYCLE ACCOMMODATIONS AND PROJECTS § 652.13 Design and construction criteria. (a) The... design of bicycle routes. Copies of the AASHTO Guide may be obtained from the American Association of... 23 Highways 1 2010-04-01 2010-04-01 false Design and construction criteria. 652.13 Section 652.13...

  11. Stabilization of expansive soil using bagasse ash & lime | Wubshet ...

    African Journals Online (AJOL)

    7-5 soil on the AASHTO classification was stabilized using 3% lime, 15% bagasse ash and 15% bagasse ash in combination with 3% lime by dry weight of the soil. The effect of the additives on the soil was investigated with respect to plastcity, ...

  12. Comprehensive evaluation of fracture critical bridges.

    Science.gov (United States)

    2014-02-01

    Two-girder steel bridges are classified as fracture critical bridges based on the definition given in the AASHTO LRFD Bridge Design Specifications. In a fracture critical bridge a failure of a tension member leads to collapse of the bridge. However, ...

  13. Preliminary studies on the utilisation of Berea Red Sands for sub-base and base construction

    CSIR Research Space (South Africa)

    Bergh, AO

    2008-07-01

    Full Text Available reflects the change in CBR values to three of the typical composite A-2-4(0) material samples (C1, C2 and C6) when treated with an anionic stable grade emulsion. 0 20 40 60 80 100 120 90 93 95 98 100 MOD AASHTO DENSITY % C B R % 25% agg...

  14. Design recommendations for the optimized continuity diaphragm for prestressed concrete bulb-T beams.

    Science.gov (United States)

    2008-01-01

    This research focused on prestressed concrete bulb-T (PCBT) beams made composite with a cast-in-place concrete deck and continuous over several spans through the use of continuity diaphragms. The current design procedure in AASHTO states that a conti...

  15. S-HAL : safety handbook for locals.

    Science.gov (United States)

    2014-01-01

    The Safety Handbook for Locals (S-HAL) is intended to be a comprehensive : traffic safety resource for all local communities in Missouri, be it cities or : counties. The S-HAL mirrors the national Highway Safety Manual (HSM) : (AASHTO, 2010) in using...

  16. Three-dimensional Finite Element Modelling of Composite Slabs for High Speed Rails

    Science.gov (United States)

    Mlilo, Nhlanganiso; Kaewunruen, Sakdirat

    2017-12-01

    Currently precast steel-concrete composite slabs are being considered on railway bridges as a viable alternative replacement for timber sleepers. However, due to their nature and the loading conditions, their behaviour is often complex. Present knowledge of the behaviour of precast steel-concrete composite slabs subjected to rail loading is limited. FEA is an important tool used to simulate real life behaviour and is widely accepted in many disciples of engineering as an alternative to experimental test methods, which are often costly and time consuming. This paper seeks to detail FEM of precast steel-concrete slabs subjected to standard in-service loading in high-speed rail with focus on the importance of accurately defining material properties, element type, mesh size, contacts, interactions and boundary conditions that will give results representative of real life behaviour. Initial finite element model show very good results, confirming the accuracy of the modelling procedure

  17. Test and Analysis of a New Ductile Shear Connection Design for RC Shear Walls

    DEFF Research Database (Denmark)

    Sørensen, Jesper Harrild; Hoang, Linh Cao; Olesen, John Forbes

    2017-01-01

    This paper presents a new and construction-friendly shear connection for assembly of precast reinforced concrete shear wall elements. In the proposed design, the precast elements have indented interfaces and are connected by a narrow zone grouted with mortar and reinforced with overlapping U......-bar loops. Contrary to the classical shear connections, the planes of the U-bar loops are here parallel to the plane of the wall elements. This feature enables a construction-friendly installation of the elements without the risk of rebars clashing. The core of mortar inside each U-bar loop is reinforced...

  18. The application of a 3D laser scanner in contemporary education of civil engineering students

    Science.gov (United States)

    Szafranko, E.; Pawłowicz, J. A.

    2017-10-01

    The programs of study in field of civil engineering include a number of objects, which concern with details of the planning, design and realization of buildings. These are buildings and structures such as, roads, bridges, tunnels, viaducts. Most of these objects are located far from university and it was difficult to show them on the lessons. Discussing the structure based on the description of the object, photographs or drawings do not always allow to imagine the actual shapes and sizes of buildings, roads, bridges and viaducts. In such a situation, terrestrial photogrammetric technology could be helpful. One of them is 3D laser scanning technology Measurements performed with a laser scanner allows to introduce selected objects in the form of spatial models. They give you the ability to rotate and zoom them in order to know the details of construction of the object. The article presents the possibility of using a 3D laser scanner in teaching.

  19. The use of ALS, botanical, and soil data to monitor the environmental hazards and regeneration capacity of areas devastated by highway construction.

    Science.gov (United States)

    Kopeć, Dominik; Woziwoda, Beata; Forysiak, Jacek; Sławik, Łukasz; Ptak, Agnieszka; Charążka, Edyta

    2016-07-01

    The impact of viaduct construction on the vegetation of a river valley was studied in Central Poland (Natura 2000 site PLH100006). The research aimed at assessing the suitability of ALS (airborne laser scanning), soil, and botanical data for monitoring the environmental effects of right-of-way reclamation 1 year after the road construction. Based on the data mentioned above, the following problems were identified: changes in topography and hydrological conditions of the valley as a result of improper land levelling, the use of inadequate soil for reclamation, no spontaneous regeneration of natural vegetation along the entire right-of-way, as well as the abundant occurrence of invasive species. The results of analysis were used to define strategies for mitigation of adverse impacts of the viaduct construction.

  20. Viaductos Requejo - la Canda - España

    Directory of Open Access Journals (Sweden)

    Llombart, José Antonio

    1976-06-01

    Full Text Available The main masonry works of the stretch Requejo- La Canda of the Access Roads to Galicia are four viaducts that span over deep valleys. The four viaducts have 37 spans each of 32.2 m length. The bridge decks are formed by prefabricated beams, in V section, joined by means of an upper slab made on the site, which in its turn establishes continuity with the adjoining bridge decks. After every third or fourth span expansion joints have been placed. The maximum height of the viaducts is 70 m. The construction of the viaducts has been carried out in quite a short time in spite of the fact that most of it has been undertaken during the winter months, with frequent snow falls and low temperatures, as the site is located in the mountains at a height that varies between 900 m and 1,300 m.Las principales obras de fábrica del tramo Requejo-La Canda de los accesos a Galicia son cuatro viaductos que franquean profundos valles. Existe un total de 37 vanos de 32,20 m de luz, a lo largo de los cuatro viaductos. Los tableros han sido resueltos mediante vigas prefabricadas, de sección en V, unidas por una losa superior construida in situ, que, a su vez, establece la continuidad entre tableros adyacentes. Se han dispuesto juntas de dilatación cada tres o cuatro vanos. La altura máxima de los viaductos es de 70 m. La construcción de los viaductos se ha realizado con gran rapidez, a pesar de haberse desarrollado gran parte de la misma en invierno, con frecuentes nevadas y bajas temperaturas reinantes, por encontrarse la obra en una zona montañosa entre las cotas + 900 y + 1.300 m.

  1. Análisis de estabilidad de taludes por el método de elementos finitos: aplicación al terraplén de entrada viaducto de Mas Rubió

    OpenAIRE

    Membreño Alarcón, Donald Francisco

    2012-01-01

    [ANGLÈS] The construction of embankments in Civil Engineering is a routine activity that involves geotechnical control activities and monitoring to ensure the stability of the embankment and surrounding structures. In this final master work an analysis and numerical modelling is done of the embankment entrance to Mas Rubió Viaduct with the Finite Element Method, using the PLAXIS 9.0 program and Mohr Coulomb constitutive model. The case is a situation of ground instability th...

  2. Optimization process for thin-walled high performance concrete sandwich panels

    DEFF Research Database (Denmark)

    Hodicky, Kamil; Hulin, Thomas; Schmidt, Jacob Wittrup

    2014-01-01

    economical solution. The present paper aims to provide multi-objective optimisation procedure addressed to structural precast thin-walled High Performance Concrete Sandwich Panels (HPCSP). The research aim is concerned with developing a tool that considers the cost of HPCSP materials along...

  3. Optimization process for thin-walled High Performance Concrete sandwich panels

    DEFF Research Database (Denmark)

    Hodicky, Kamil; Hulin, Thomas; Schmidt, Jacob Wittrup

    2013-01-01

    economical solu-tion. The present paper aims to provide multi-objective optimisation procedure addressed to structural precast thin-walled High Performance Concrete Sandwich Panels (HPCSP). The research aim is concerned with de-veloping a tool that considers the cost of HPCSP materials along...

  4. Office Building, Roskilde, Denmark. Parkvænget 25, 4000 Roskilde

    DEFF Research Database (Denmark)

    Rose, Jørgen; Thomsen, Kirsten Engelund

    Built in 1968 the office building was a typical precast concrete building with a very limited level of insulation. In 1991 the building envelope was renovated and insulation was added to the wall (175 mm) and windows were replaced with traditional double-glazed windows. The main objective...

  5. Portable concrete barrier condition and transition plan synthesis.

    Science.gov (United States)

    2012-06-01

    Precast (or portable) Concrete Barrier (PCB) is a guardrail system that is intended to contain and redirect a vehicle that has left the travel lane. Barrier connections are typically formed using steel wire or bar to form loops which are joined by a ...

  6. Investigation and development of an effective, economical and efficient concrete pile splice : [summary].

    Science.gov (United States)

    2015-08-01

    Large structures like bridges or tall buildings are often built on deep foundations either precast concrete piles or cast-in-place drilled shafts. The pile or shaft must be long enough to reach : a rock layer or to provide sufficient resistance t...

  7. Assessment of concrete characteristics during the deliberate deformation of a flexible mould after casting

    NARCIS (Netherlands)

    Schipper, H.R.; Grunewald, S.; Troian, S.; Raghunath, P.; Schlangen, H.E.J.G.; Copuroglu, O.; Pecur, I.B.; Baricevic, A.; Stirmer, N; Bjegovic, D.

    2017-01-01

    Expensive CNC (computer numerical controlled)-milled formwork is required for the production of double-curved precast concrete elements for cladding or shell structures. The innovative flexible mould method for economically efficient and sustainable production of such elements, developed at Delft

  8. In-plane Shear Joint Capacity of Pracast Lightweight Aggregate Concrete Elements

    DEFF Research Database (Denmark)

    Larsen, Henning; Goltermann, Per; Scherfig, Søren

    1996-01-01

    The paper establishes and documents formulas for the in-plane shear capacity between precast elements of lightweight aggregate concrete with open structure. The joints investigated are rough or toothed and have all been precracked prior to the testing in order to obtain realistic test results...

  9. Seismic strengthening of RC structures with exterior shear walls

    Indian Academy of Sciences (India)

    research efforts in this field have shifted their focus to new methods that could overcome this difficulty. The precast panel infill ... the sides of the buildings to be unobstructed for installation of new shear walls. The literature review presents ..... Seismic design of bridge piers. Research report 84-2, Christchurch (New Zealand),.

  10. Anghel Saligny : Omul şi Monumentul

    Directory of Open Access Journals (Sweden)

    Iulia Băjenaru

    2012-03-01

    Full Text Available Anghel Saligny was a remarcable engineer, world wide predecessor of metal building science and reinforced concrete, creator of multiple inventions and of unique solutions in designing and building bridges, industrial constructions, for the foundation of port piers and docks, as well as grain silos through the use of precast concrete, all of these in world premiere.

  11. Testing of Shelter Design and Industrial Hardening Concepts at the MILL RACE Event.

    Science.gov (United States)

    1982-01-01

    accordance with Chapter 26 and the 1978 edition of the CRSI Handbook (Ref. II). The precast prestressed concrete slabs and beams were designed in accordance...Building Code Requirements for Reinforced Concrete (ACI 318-77), American Concrete Institute, Detroit, MI, 1977. 11. CRSI Handbook, Concrete Reinforcing

  12. Determining the in situ concrete strength of existing structures for assessing their structural safety

    NARCIS (Netherlands)

    Steenbergen, R.D.J.M.; Vervuurt, A.H.J.M.

    2012-01-01

    EN 13791 applies when assessing the in situ compressive strength of structures and precast concrete components. According to the code itself, it may be adopted when doubt arises about the compressive strength of a concrete. For assessing the structural safety of existing structures, however, the

  13. Strength characteristics for the structural assessment of existing concrete structures

    NARCIS (Netherlands)

    Vervuurt, A.; Courage, W.; Steenbergen, R.

    2013-01-01

    For the assessment of the in situ compressive strength in structures and precast concrete components EN 13791 applies. Among others, this standard may be adopted when doubt arises about the compressive strength in the structure. However, for assessing the structural safety of existing structures of

  14. NIGERIAN VETERINARY JOURNAL

    African Journals Online (AJOL)

    ADEYEYE

    Escherichia coli isolated from a Swedish patient that earlier received a medical care in. India and it ... the world, following its initial description. (Walsh, 2010). It has been reported in different parts of the world such as: ... precasted E- gel in an Electrophoresis unit. (Life Technologies). The amplified products were purified with.

  15. Research Article Special Issue

    African Journals Online (AJOL)

    2016-05-15

    May 15, 2016 ... ABSTRACT. Precast prestressed concrete pavement (PC on PCP performance is not available in lite of the potential benefits of prestressing on dimensional (3D) Finite-element modelin prestressed pavement had been discussed. prestressing forces were analyzed. It was deflection at mid slab but the ...

  16. Finite element investigation of the prestressed jointed concrete ...

    African Journals Online (AJOL)

    Precast prestressed concrete pavement (PCP) technology is of recent origin, and the information on PCP performance is not available in literature. This research presents a finite-element analysis of the potential benefits of prestressing on the jointed concrete pavements (JCP). With using a 3-dimensional (3D) ...

  17. SCC and conventional concrete on site: property assessment

    Directory of Open Access Journals (Sweden)

    S. Nunes

    Full Text Available The present paper deals with comparing properties of hardened SCC cast during first full-scale tests in a precast factory and similar conventional concrete currently used in the same factory. The main goal was to evaluate viability of replacing the C45/55 conventional concrete, in use at the precast factory, by a SCC of the same class of resistance and maintaining the constituent materials. A wide number of specimens (cubes, cylinders, prisms and full size precast elements were cast with both SCC and conventional vibrated concrete to enable comparing different properties of both types of hardened concrete. In order to implement SCC in this precast factory, suitability of actual current processes involved in production, mixing, transport and placing had to be evaluated. SCC exhibited improved mechanical behavior, higher resistance to fluid ingress and a more uniform strength along the full-size element due to a combination of proper mixdesign together with controlled mixing and placing on site.

  18. Investigation on the Mechanisms Governing the Robustness of Self-Compacting Concrete at Paste Level

    NARCIS (Netherlands)

    van der Vurst, F; Lesage, Karel; Grunewald, S.; Vandewalle, Lucie; Vantomme, John; Schutter, G; Khayat, Kamal H.

    2016-01-01

    In spite of the many advantages, the use of self-compacting concrete
    (SCC) is currently widely limited to application in precast factories and sihiations
    in which external vibration would cause large difficulties. One of the main
    limitations is the higher sensitivity to small variations

  19. Spread prestressed concrete slab beam bridges.

    Science.gov (United States)

    2015-04-01

    TxDOT uses prestressed slab beam bridges for short-span bridges ranging from approximately 3050 ft in : length. These bridges have precast, pretensioned slab beams placed immediately adjacent to one another : with a cast-in-place slab made composi...

  20. 76 FR 4471 - Privacy Act of 1974; Report of Modified or Altered System of Records

    Science.gov (United States)

    2011-01-25

    ... medical and epidemiological research, statistical analysis, and to identify early indicators of... to perform medical and epidemiological research, statistical analysis, and to identify early... the facility, which is of structural steel and cement block construction, with pre-cast cement panels...

  1. Fragmentation of Solid Materials Using Shock Tubes. Part 2: First Test Series in a Large Diameter Shock Tube

    Science.gov (United States)

    2017-12-01

    Figure 2. Typical test setup including shock tube, expansion section, sample mounting and fragment containment structure ...34 architectural precast panel (p=50-psi, t=100-msec) as predicted by LS-DYNA...overpressure airblast, creating conditions where material properties (e.g., strength, density) dominate structural response (e.g., bending, flexing

  2. Forensic testing of prestress concrete girders after forty years of service.

    Science.gov (United States)

    2013-09-01

    This report describes an investigation to quantify the behavior of precast, prestressed concrete : bridge girders made with high-strength concrete. As part of the investigation, four bridge : girders that were made with 77.2 MPs (11.2 ksi) concrete w...

  3. The carbon footprint and embodied energy of construction material ...

    African Journals Online (AJOL)

    4.4 Material choices. Low-carbon footprint and embodied energy-intensive materials have been identified and selected through an iterative simulation process. The design proposes minimal use of precast concrete and steel, while extensively using recycled materials such as aggregate and composite timber and resin slats.

  4. Construction of prestressed concrete single-tee bridge superstructures.

    Science.gov (United States)

    1977-01-01

    This report discusses in detail the construction of the first five precast, prestressed concrete, single-tee beam bridge superstructures to be let to contract in Virginia. The data suggest that this single-tee beam enables efficient construction of t...

  5. Forensic collapse investigation of a concrete bridge with timber piers.

    Science.gov (United States)

    2009-04-01

    This report outlines the forensic investigation of the collapse of Bridge No. SN 019-5010 in DeKalb County, : Illinois on August 19, 2008. The bridge consisted of three 42 feet precast prestressed concrete deck beams : simply-supported by concrete pi...

  6. A Case Study On Pile Relaxation In Dilative Silts

    Science.gov (United States)

    2011-12-20

    along the proposed track of the bridge . It is interesting to note that the geotechnical consultant, SPA, recommended precast prestressed concrete ...Pile Test Program, Prestressed Concrete Piles, Jamestown Bridge Replacement. Consulting Engineer. Davisson, M. T. (1989). Summary of Composite Pile...Test Program, Composite Prestressed - Concrete and Steel H-Piles, Jamestown Bridge Replacement. Consulting Engineer. Fellenius, B. H. (2009). Basics of

  7. Assessing Corrosion Damage and Corrosion Progression in Multistrand Anchor Systems in Use at Corps Projects

    Science.gov (United States)

    2013-07-01

    evaluation of prestressing steel strands in concrete bridges . Final Report, Phase I: Technology Review, Transportation Research Board National Research...Inspection methods and techniques to determine non- visible corrosion of prestressing strands in concrete bridge components. Pennsylvania Department...cracking in post-tensioned concrete box girder bridges and retrofit procedures. Precast/ Prestressed Concrete Institute Journal, March- April. Podolny, W

  8. Nonlinear phased analysis of reinforced concrete tunnels under fire exposure

    NARCIS (Netherlands)

    Lilliu, G.; Meda, A.

    2013-01-01

    Fire analysis of precast segmental tunnels involves several problems, mainly related to the soil-structure interaction during fire exposure, coupled with material degradation. Temperature increase in the tunnel is the cause of thermal expansion of the lining, which is resisted by the soil pressure.

  9. Use of SCC in Prefabricated Concrete Elements

    DEFF Research Database (Denmark)

    Thrane, Lars Nyholm; Lauritsen, Ib

    2004-01-01

    This paper presents observations made on the use of self-compacting concrete for pre-cast elements at Byggebjerg Beton A/S during the last 3 years. The elements include L- and sandwich elements and are mainly produced for agriculture purposes. In general, the flow properties and air content...

  10. Measures of struggle against appearance of cracks in earth dams

    Directory of Open Access Journals (Sweden)

    Ibraeva Yulia

    2016-01-01

    Full Text Available The article describes a method calculation of the basic parameters of the transverse rows of pile of simple printed or precast dam. As well, in this article have been shown all the necessary formulas for this calculation and have been proposed solutions to prevent cracking in the dams.

  11. Energy Efficiency Improvement and Cost Saving Opportunities for the Concrete Industry

    NARCIS (Netherlands)

    Kermeli, Katerina; Worrell, E.; Masanet, Eric

    2011-01-01

    The U.S. concrete industry is the main consumer of U.S.-produced cement. The manufacturing of ready mixed concrete accounts for about 75% of the U.S. concrete production following the manufacturing of precast concrete and masonry units. The most significant expenditure is the cost of materials

  12. Assembly and lifting of Pearl-Chain arches

    DEFF Research Database (Denmark)

    Halding, Philip Skov; Hertz, Kristian Dahl; Viebæk, N.E.

    2015-01-01

    in buildings and bridges. The assembly and lifting of two Pearl-Chain arches, with a span of 13 m and rise of 1 m, is considered in this paper. Precast “Super-Light Deck” elements were used for the arches, which had a thickness of 22 cm. Both arches were successfully lifted, rotated in mid-air, and placed...

  13. 76 FR 11424 - Notice of Petitions by Firms for Determination of Eligibility To Apply for Trade Adjustment...

    Science.gov (United States)

    2011-03-02

    ... architectural panels, curbs, hand holes, 02351. pull boxes, light bases, and bumper logs. Richards Sheet Metal.../pillow blocks, metal stampings and custom products. ] Martin David, Inc 68-B Winter Street, 11-Feb-11 The...), forming and centrifugal pump machinery Ridgefield, WA 98642. and parts. Precast Specialties 999 Adams...

  14. Double-curved textile reinforced concrete panels with tensile strain-hardening characteristics

    NARCIS (Netherlands)

    Kok, M.; Schipper, H.R.; Grunewald, S.; Nijsse, R.

    2014-01-01

    The construction of buildings with fi-ee-form surfaces can be accompanied with relatively high costs. An innovative method to produce free-form surfaces in concrete is the application of double-curved precast panels produced with a flexible re-usable mould technique. Traditional placing of

  15. Performance of pile foundation for the civil infrastructure of high speed rail in severe ground subsidence area

    Directory of Open Access Journals (Sweden)

    H. W. Yang

    2015-11-01

    Full Text Available In this study, the performance of pile foundation is assessed for the 30 km long viaduct bridge structure seating in the ground subsidence area in the central part of Taiwan. The focus of this paper is placed on the settlement behaviour of a continuous 3-span R. C. viaduct bridge supported on piles adjacent to highway embankment. Monitoring data accumulated over the last 12 years indicate that the observed pace of the settlement of the viaduct structure in other sections matches that of the ground. However, the bridge piers adjacent to the embankment have been suffering an additional approximately 1 cm settlement every year since the completion of the embankment construction. It was believed that the piers may suffer from enormous negative skin friction owing to the surcharge from the embankment and groundwater depression. This paper first summarizes the settlement analysis results to quantify the settlement of pile due to regional ground subsidence and the combined effects from ground water fluctuation and embankment surcharge loading. Accordingly, a loading path on P'-q stress space is formulated to illustrate the loading variation subject to the combined loading effects that can explain why the combined effect becoming significant on settlement control for civil infrastructure in ground subsidence area.

  16. Performance of pile foundation for the civil infrastructure of high speed rail in severe ground subsidence area

    Science.gov (United States)

    Yang, H. W.

    2015-11-01

    In this study, the performance of pile foundation is assessed for the 30 km long viaduct bridge structure seating in the ground subsidence area in the central part of Taiwan. The focus of this paper is placed on the settlement behaviour of a continuous 3-span R. C. viaduct bridge supported on piles adjacent to highway embankment. Monitoring data accumulated over the last 12 years indicate that the observed pace of the settlement of the viaduct structure in other sections matches that of the ground. However, the bridge piers adjacent to the embankment have been suffering an additional approximately 1 cm settlement every year since the completion of the embankment construction. It was believed that the piers may suffer from enormous negative skin friction owing to the surcharge from the embankment and groundwater depression. This paper first summarizes the settlement analysis results to quantify the settlement of pile due to regional ground subsidence and the combined effects from ground water fluctuation and embankment surcharge loading. Accordingly, a loading path on P'-q stress space is formulated to illustrate the loading variation subject to the combined loading effects that can explain why the combined effect becoming significant on settlement control for civil infrastructure in ground subsidence area.

  17. Uso de aisladores de base en puentes de concreto simplemente apoyados

    Directory of Open Access Journals (Sweden)

    Leocadio Rico Pradilla

    2012-12-01

    Full Text Available The aim of this paper is to present a comparison of the seismic behavior of simply supported concrete bridges by using three types of base isolators, namely high damping rubber bearing (HDRB, lead rubber bearing (LRB and friction pendulum system (FPS. “La Flora” viaduct is taken as case study; the geometry and the corresponding modeling of such viaduct are defined in sap2000. Additionally, the mechanical properties of three insulators are defined using a bilinear model. An analysis of histories in time was made for the model of the viaduct, considering the non-linearity in the insulators and using frontal fault earthquakes caused by the Frontal and Bucaramanga-Santa Marta fault; this is applied at a surface-level scale. The results from the model without seismic isolation are compared with the three systems of seismic isolation and the findings suggest that the different systems of seismic isolation significantly reduce both the demands of the displacements and the cutting forces in the piles of the bridge, which may induce probable earthquakes.

  18. Analisis Perbandingan Pengaruh Penggunaan Flyslab dan Plat Floordeck dalam Mewujudkan Lean Construction

    Directory of Open Access Journals (Sweden)

    Edwin Sandagie

    2016-10-01

    Full Text Available Nowadays there are several kinds of products innovations in the construction industry, one of whom is a precast concrete slab. In fact, products of innovation are not necessarily fully able to provide a positive impact, both in terms of cost, quality, time, and waste on building construction projects. Moreover, what is offered by the manufacturer of precast concrete slab has not necessarily correspond with the needs of the customer. The purpose of this study is to analyze the comparison of products in terms of time, cost, quality, and waste between projects using precast concrete slab and the same projects that were simulated using floordeck concrete slab. This research will: (1 simulate the project if not using precast concrete slab product, (2 analyze the comparison of products in terms of time, cost, quality, and waste between the real project and the simulation project, (3 calculate the benefits obtained from the use of precast concrete slab product. The use of flyslab at Pertamina Parking Building Project (which consists of three floors and two floors using flyslab when compared with the results of the simulation project that uses floordeck concrete slab: (1 in terms of time, it can provide a savings of 12.5% of the total duration of the simulation project, (2 in terms of costs, it can provide costs savings on the total cost structure reaches 23.13%, (3 in terms of quality, flyslab constituent materials are designed to have a higher quality when compared to floordeck concrete slab constituent materials, (4 in terms of waste, on a project that uses flyslab, the amount of waste generated is much less when compared to the results of the simulation project that uses a floordeck concrete slab.

  19. Experimental Study on Forecasting Mathematical Model of Drying Shrinkage of Recycled Aggregate Concrete

    OpenAIRE

    Yuanchen Guo; Xue Wang

    2012-01-01

    On the basis of basic law in AASHTO2007 model, the forecasting mathematical model of drying shrinkage of recycled aggregate concrete (RAC) is established by regression analysis and experimental study. The research results show that (1) with the replacement rate of RCA increases, the drying shrinkage value of RAC increases; this trend is even more obvious in the early drying time. (2) The addition of fly ash can inhibit the drying shrinkage of RAC, but the effect is not very obvious. Specifica...

  20. Oyelami & Alimi (8).cdr

    African Journals Online (AJOL)

    Timothy Ademakinwa

    plasticity index of 9.63 to 31.13% and linear shrinkage of 1.43 – 27.86%. The soils fall within the A-2-7 to A-7-5 of the AASHTO classification scheme. The specific gravity of 2.20-2.73 showed a lower degree of laterization. 3. The Maximum Dry Density, (MDD) ranged from 1.32– 2.15 Mg/m while Optimum Moisture Content, ...

  1. Field Testing and Load Rating Report for Bridge No. 4, Hybrid Composite Beam Span, at Fort Knox, Kentucky

    Science.gov (United States)

    2016-09-01

    consists of two simply supported spans. One span is comprised of five rolled steel girders supporting a non-composite reinforced concrete slab . The...load configuration. Additionally, a controlling MLC vehicle classification was determined for the bridge for both tracked and wheeled configurations...span. The MLC values for tracked and wheeled vehicles were based on AASHTO Operating Load Factors. A tracked MLC of 139 tons was obtained from an

  2. Feasibility of fiber reinforced composite materials used in highway bridge superstructures

    OpenAIRE

    Lin, Shih-Yung

    1988-01-01

    Composite materials are considered here as structural materials of highway bridge superstructures. Bridge deck designs can be done according to AASHTO1 specification and elastic design concepts. In order to evaluate the feasibility of composites as structural materials of highway bridge superstructures, composite materials are compared not only to composite materials themselves but also to the most popular bridge structural materials, which are reinforced concrete and struc...

  3. Determinación probabilística del tiempo de servicio de Estructuras de Pavimentos

    Directory of Open Access Journals (Sweden)

    Mario Rodríguez

    Full Text Available En Chile, como en muchos países de Suramérica, AASHTO 93 es el método oficial para el diseño de pavimentos asfálticos. El método entrega un número estimado de ejes equivalentes estándar de 80 kN que el pavimento puede soportar hasta alcanzar un cierto valor de serviciabilidad. Un factor de seguridad es luego aplicado al número estimado de ejes equivalente tomando en cuenta el nivel de confianza y la varianza estimada de los datos de entrada utilizados en el método, con lo cuál se estima la magnitud del ciclo de vida de la estructura. Normalmente, los datos utilizados en el método AASHTO 93 son asumidos como valores deterministas, sin tomar en cuenta su naturaleza aleatoria. Este trabajo presenta una evaluación probabilística del método de diseño AASHTO 93 de pavimentos bajo condiciones chilenas, el cuáll proporciona un conjunto de funciones de densidad de probabilidad, que permiten realizar la estimación probabilística del ciclo de vida del pavimento en términos del valor del número de ejes equivalente. Para alcanzar el objetivo se desarrollo un modelo de simulación a partir de una muestra de 13 grupos de carreteras ubicados a largo de Chile.

  4. Load carrying capacity of keyed joints reinforced with high strength wire rope loops

    DEFF Research Database (Denmark)

    Jørgensen, Henrik B.; Hoang, Linh Cao

    2015-01-01

    Vertical shear connections between precast concrete wall elements are usually made as keyed joints reinforced with overlapping U-bars. The overlapping U-bars form a cylindrical core in which the locking bar is placed and the connection is subsequently grouted with mortar. A more construction...... friendly shear connection can be obtained by replacing the U-bars with high strength looped wire ropes. The wire ropes have the advantage of being flexible (they have virtually no bending stiffness) which makes installation of wall elements much easier. The looped wire ropes are usually pre-installed in so......-called wire boxes which are embedded in the precast wall elements. Once the joint is grouted with mortar, the boxes will function as shear keys and the overlapping wire loops will function as transverse reinforcement that replaces the U-bars. This paper presents a rigid-plastic upper bound model to determine...

  5. Load Carrying Capacity of Keyed Joints Reinforced with High Strength Wire Rope Loops

    DEFF Research Database (Denmark)

    Jørgensen, Henrik Brøner; Hoang, Linh Cao

    Vertical shear connections between precast concrete wall elements are usually made as keyed joints reinforced with overlapping U-bars. The overlapping U-bars form a cylindrical core in which the locking bar is placed and the connection is subsequently grouted with mortar. A more construction...... friendly shear connection can be obtained by replacing the U-bars with high strength looped wire ropes. The wire ropes have the advantage of being flexible (they have virtually no bending stiffness) which makes installation of wall elements much easier. The looped wire ropes are usually pre-installed in so......-called wire boxes which are embedded in the precast wall elements. Once the joint is grouted with mortar, the boxes will function as shear keys and the overlapping wire loops will function as transverse reinforcement that replaces the U-bars. This paper presents a rigid-plastic upper bound model to determine...

  6. Two innovative solutions based on fibre concrete blocks designed for building substructure

    Science.gov (United States)

    Pazderka, J.; Hájek, P.

    2017-09-01

    Using of fibers in a high-strength concrete allows reduction of the dimensions of small precast concrete elements, which opens up new ways of solution for traditional construction details in buildings. The paper presents two innovative technical solutions for building substructure: The special shaped plinth block from fibre concrete and the fibre concrete elements for new technical solution of ventilated floor. The main advantages of plinth block from fibre concrete blocks (compared with standard plinth solutions) is: easier and faster assembly, higher durability and thanks to the air cavity between the vertical part of the block, the building substructure reduced moisture level of structures under the waterproofing layer and a comprehensive solution to the final surface of building plinth as well as the surface of adjacent terrain. The ventilated floor based on fibre concrete precast blocks is an attractive structural alternative for tackling the problem of increased moisture in masonry in older buildings, lacking a functional waterproof layer in the substructure.

  7. Introduction of an Innovative Cladding Panel System for Multi-Story Buildings

    Directory of Open Access Journals (Sweden)

    Hathairat Maneetes

    2014-08-01

    Full Text Available An Energy Dissipating Cladding System has been developed for use in buildings designed based on the concept of damage-controlled structure in seismic design. This innovative cladding panel system is capable of functioning both as a structural brace, as well as a source of energy dissipation, without demanding inelastic action and ductility from the basic lateral force resisting system. The structural systems of many modern buildings typically have large openings to accommodate glazing systems, and a popular type of construction uses spandrel precast cladding panels at each floor level that supports strip window systems. The present study focuses on developing spandrel type precast concrete cladding panels as supplementary energy dissipating devices that are added to the basic structural system. Through a series of analytical studies, the result of evaluating the ability of the proposed Energy Dissipating Cladding system to improve the earthquake resistance of the buildings is presented here.

  8. Turbine component, turbine blade, and turbine component fabrication process

    Science.gov (United States)

    Delvaux, John McConnell; Cairo, Ronald Ralph; Parolini, Jason Robert

    2017-05-30

    A turbine component, a turbine blade, and a turbine component fabrication process are disclosed. The turbine component includes ceramic matrix composite plies and a feature configured for preventing interlaminar tension of the ceramic matrix composite plies. The feature is selected from the group consisting of ceramic matrix composite tows or precast insert tows extending through at least a portion of the ceramic matrix composite plies, a woven fabric having fiber tows or a precast insert preventing contact between a first set of the ceramic matrix composite plies and a second set of the ceramic matrix composite plies, and combinations thereof. The process includes laying up ceramic matrix composite plies in a preselected arrangement and securing a feature configured for interlaminar tension.

  9. Shear Resistance between Concrete-Concrete Surfaces

    Science.gov (United States)

    Kovačovic, Marek

    2013-12-01

    The application of precast beams and cast-in-situ structural members cast at different times has been typical of bridges and buildings for many years. A load-bearing frame consists of a set of prestressed precast beams supported by columns and diaphragms joined with an additionally cast slab deck. This article is focused on the theoretical and experimental analyses of the shear resistance at an interface. The first part of the paper deals with the state-of-art knowledge of the composite behaviour of concrete-concrete structures and a comparison of the numerical methods introduced in the relevant standards. In the experimental part, a set of specimens with different interface treatments was tested until failure in order to predict the composite behaviour of coupled beams. The experimental part was compared to the numerical analysis performed by means of FEM basis nonlinear software.

  10. Mechanical Properties of UHPFRC Joint for FORIDA Wind Turbine Tower

    DEFF Research Database (Denmark)

    Sørensen, Eigil Verner

    FORIDA Development, Vestas and Aalborg University are currently undertaking the project “FORIDA Hybrid Towers – The towers for next generation of wind turbines”, aiming to develop a new wind turbine tower structure (The FORIDA Tower) for very tall turbines. The tower is going to be a hybrid of ma...... of materials combining steel and Ultra High Performance Fibre Reinforced Concrete (UHPFRC), applied as precast units. The FORIDA Tower is competitive regarding price, design, flexibility and durability....

  11. Peningkatan Produktivitas Konstruksi Melalui Pemilihan Metode Konstruksi

    Directory of Open Access Journals (Sweden)

    Paulus Setyo Nugroho

    2012-02-01

    Full Text Available Productivity growth in the construction is lower than that of in the industry sector. Level of innovation in this sector is too low. Many problems of inefficiency in the construction process are a lotof waste of resources that do not produce value. According to  LCI (Lean ConstructionInstitute waste in the construction industry is about 57% while the activity that adds value is only 10%. The construction industry has a lot to learn from manufacture industry. Some innovations by applying an appropriate and efficient  methods in the field of construction adopted many of the manufacturing, including modular systems/fabrication (precast concrete. Construction materials are mass produced in acontrolled environment and then assembled inthe site. The use of precast on any project shows that there are advantages obtained are: cheaper, faster/more productive and guaranteed quality. The duration of the Rusunawa (Simple Flats for Rent Structure construction phase in Cilacap for precast method is 168 days while for the implementation of the conventional method is 196 days. The duration of the construction of precast structures is faster 28 days (14% faster than that of the conventional structures. In high-speed rail project on the border of Belgium and the Netherlands, use Rheda 2000 NL method, which development of Rheda method, can increase productivity and lower overtime costs as 24.6%. In the residential case, quicklyconstructed building criteria can be categorizedinto several aspects, such as dimensions, weight components and connection systems.The suitable selection criteria will accelerate instalment proses of the wall panel.

  12. An Alternative Technique for Fabrication of Frameworks in an Immediate Loading Implant Fixed Mandibular Prosthesis

    Science.gov (United States)

    Paleari, André Gustavo; Presoto, Cristina Dupim; Vasconcelos, Juliano Alencar; Nunes Reis, José Maurício dos Santos; Pinelli, Lígia Antunes Pereira; Tavares da Silva, Regina Helena Barbosa; Quishida, Cristiane Campos Costa

    2015-01-01

    The oral rehabilitation of edentulous patients with immediate loading has become a safe procedure with high predictability. The success is related to immediate fabrication of a passive fit framework to attach the implants. Based on these considerations, this case report shows an alternative technique for mandibular rehabilitation using implants immediately loaded, where the framework was fabricated using cylinders with internal reinforcement and precast pieces, electrowelding, and conventional welding providing esthetics and function to the patient in a short period of time. PMID:25628899

  13. 超高強度繊維補強コンクリートを用いた複層立体トラスの開発(構造)

    OpenAIRE

    長谷川, 嘉子; 金久保, 利之; 飯干, 福馬; 白井, 一義; 米丸, 啓介

    2008-01-01

    This study aims to develop a truss system by precast concrete members using Ultra High Strength Fiber Reinforced Concrete, UFC, which shows ductile behavior and high durability. A pyramid shaped truss with prestressed truss members were designed, and a constructional experiment was carried out. The result of cyclic loading test on the pyramid shaped truss demonstrated that this structure could be applied to an actual double layer space truss structure. Finally, the failure process of the stru...

  14. Experimental analysis of properties of high performance recycled aggregate concrete

    OpenAIRE

    Gonzàlez Corominas, Andreu; Etxeberria Larrañaga, Miren

    2014-01-01

    Due to the increase in the demolition of high strength concrete structures and the interest of precast concrete companies in being more competitive, it is necessary to analyse the use of recycled concrete aggregates (RCA) in high performance concrete (HPC). In this study, HPC were produced using 20%, 50% and 100% of RCA on substitution of natural coarse aggregates. Three types of RCA were used, they were produced crushing original concrete of 100, 60 and 40 MPa of compressive strength. The ph...

  15. Sustainability applied to prefabrication

    OpenAIRE

    Fernández-Ordoñez, David; Fuente Antequera, Albert de la

    2016-01-01

    Prefabrication has evolved in depth and breadth from its beginnings, bringing many of the advantages of industrialisation to construction, while solving some of the problems that arose in the early years. Today prefabrication, compared to traditional construction methods, and concrete as a material, feature a number of beneficial characteristics. Precast elements are factory made products. The only way to industrialise the construction industry is to shift work from temporary construction sit...

  16. Inovasi Tandon Air Beton Pracetak: Karakteristik Teknis dan Kelayakan Ekonomi

    OpenAIRE

    Setya Winarno; Fitri Nugraheni; Ari Rudatin

    2015-01-01

    Currently, concrete water tank with ”cast in situ” method has still been using conventional technology and needed long construction schedule. This novel research innovates concrete water tank with ”precast” method which corresponds to Indonesian Standard (SNI) and is able to compete in open market price. The stage of the research begun with an investigation to an existing plant of concrete water tank and testing of characteristic analysis of concrete material and precast panels with variety d...

  17. Energy Dissipation from Vibrating Floor Slabs due to Human-Structure Interaction

    Directory of Open Access Journals (Sweden)

    James M.W. Brownjohn

    2001-01-01

    Full Text Available Lightweight pre-cast flooring systems using post-tensioning to increase strength but not stiffness are increasingly popular, and vibration serviceability problems tend to govern design of such floors where human occupants are increasingly concerned with vibrations. At the same time as inducing response, stationary human observers can also participate in the response as mitigating influence and it is clear that a human behaves as a highly effective damper, even when seated.

  18. Bubbledeck floor system: a brief presentation

    OpenAIRE

    Liana TEREC; Mircea TEREC

    2013-01-01

    The BubbleDeck slab is a floor system of reinforced concrete, containing spherical hollows, as concrete saving elements. The system allows longer spans between columns supports. Usually manufactured partially from precast filigree elements, the BubbleDeck system combines the benefits of factory-manufactured elements in controlled conditions with on site completion with the final monolith concrete, resulting in a completed floor slab. Regarding the BubbleDeck system, numerous experimental rese...

  19. Recycled Concrete as Aggregate for Structural Concrete Production

    OpenAIRE

    Mirjana Malešev; Vlastimir Radonjanin; Snežana Marinković

    2010-01-01

    A comparative analysis of the experimental results of the properties of fresh and hardened concrete with different replacement ratios of natural with recycled coarse aggregate is presented in the paper. Recycled aggregate was made by crushing the waste concrete of laboratory test cubes and precast concrete columns. Three types of concrete mixtures were tested: concrete made entirely with natural aggregate (NAC) as a control concrete and two types of concrete made with natural fine and recycle...

  20. Corrosion Protection for Military Construction in the Middle East

    Science.gov (United States)

    1985-09-01

    anodes."’ 2 Preferably, tower footings should be supported above-grade on steel-reinforced concrete pads. Corrosion Mitigation: TransformerST an3formers...Filling, and Backfillingfor Buildings 02312 CEGS-02362 Prestressed Concrete Piling 02313 CE-202.07 Piling; Concrete , Precast 02315 CEGS-02360 Steel H-Piles...environ- meat in these countries is unique-desert sands, high winds , and warm, salt-laden air from the surrounding sea-allowing even the most durable

  1. Arquitectura vertida

    Directory of Open Access Journals (Sweden)

    Sánchez-Mora, F.

    2006-09-01

    Full Text Available Miguel Fisac invented a construction procedure based on precast members that combined structural enclosures with built-in services and hollow core slabs, referred to here as “flowing architecture”.Miguel Fisac inventa un procedimiento constructivo basado en elementos prefabricados que combina paneles estructurales de cerramiento con instalaciones incluidas y placas alveolares, al que llamamos “Arquitectura vertida”.

  2. Development of an accelerated test for Internal Sulfate Attack study

    OpenAIRE

    Khelil Nacim; Aubert Jean-Emmanuel; Escadeillas Gilles

    2014-01-01

    Internal Sulfate Attack (ISA) is a pathology that occurs under certain conditions in concrete having undergone heating above 70 °C at early age (through heating in pre-casting industry or due to hydration in large concrete parts). This reaction deemed very slow, numerous methods to speed up reactions leading to delayed ettringite formation have been developed. These methods are all based on the material damage. Another type of test is currently under development. It is based on rehabilitation...

  3. The consequences of the use of concretes with high alumina cement in Madrid

    OpenAIRE

    Macías Hidalgo-Saavedra, Fernando

    1992-01-01

    This article presents, in the first place, the idea coming from the Madrid Town Council (Ayuntamiento de Madrid) to study the dwellings built with high alumina cement, comparing the case of Madrid with those qf other Spanish municipalities. The article also includes one particular case, that of the Vicente Calderón Stadium (Madrid) where we can see what was done after the detection of high alumina cement in prestressed precast beams of the inclined slabs which supported the tiers of the...

  4. Tilt-up construction

    OpenAIRE

    Crompton, Richard E.

    1992-01-01

    CIVINS Tilt-up construction is a special form of precast concrete construction. The technique is used for constructing buildings by prefabricating concrete wall sections (panels) in a horizontal position on either the building's floor slab or on a temporary casting slab. Once the wall sections have cured, they are tilted to a vertical position using a mobile crane, they are temporarily braced in their final upright position, and finally, they are tied into the building's roof and floor sys...

  5. Foundation Construction in a Reclaimed Marginal Land: A Case Study

    African Journals Online (AJOL)

    A sand-filled land situated in a mangrove swamp area in the Niger Delta is to be used for the erection of a factory for the production of pre-cast concrete electric poles. The soil profile for the site comprises a hydraulically-placed top sand about 2 metres in thickness, under-lain by very soft organic clay which in turn rests on a ...

  6. Comparison of Conventional and Advanced Concrete Technologies in terms of Construction Efficiency

    Directory of Open Access Journals (Sweden)

    Matej Špak

    2016-01-01

    Full Text Available Nowadays, high-performance concrete (HPC and ultra-high-performance concrete (UHPC are ranked among advanced concrete technologies. The application of the mentioned advanced technologies may have potential to improve the construction efficiency from several points of view. For instance, reducing of construction time and construction material, construction quality improving, environmental impact minimizing, and increasing of both durability and lifetime of structures as well as reducing of total construction costs may be obtained. Particular advanced concrete technologies are described and the possibilities of their utilization in both monolithic structures and precast units are presented in the article. The main benefits of modern methods of construction (MMC based on advanced concrete technologies application in precast elements production are presented. Regarding the selected aspects of construction efficiency assessment, a comparison of conventional and advanced concrete technologies that are applied in monolithic structures and precast units is made. The results of this comparison, estimated in semantic differential scale, are presented in the article. By the results of the comparison, the significance of applying the advanced concrete technologies in modern methods of concrete structures production is demonstrated in order to improve construction efficiency.

  7. Investigation of Tension Forces in A Stay Cable System of A Road Bridge Using Vibration Methods

    Directory of Open Access Journals (Sweden)

    Hawryszków Paweł

    2015-01-01

    Full Text Available In the article author presents method of investigation of tension forces in stay cable systems using dynamical methods. Research was carried out during stay cable system installation on WN-24 viaduct near Poznań, that is way it was possible to compare tension forces indicated directly by devices using for tensioning of cable-stayed bridges with results achieved indirectly by means of dynamical methods. Discussion of results was presented. Advantages of dynamical methods and possible fields of application was described. This method, which has been rarely used before, may occur interesting alternative in diagnostics of bridges in comparison to traditional methods.

  8. El viaducto de Boudry

    Directory of Open Access Journals (Sweden)

    Sarrasin, Alexandre

    1963-04-01

    Full Text Available To improve the road traffic between Iverdon and Neuchâtel (Switzerland the layout of the motorway has been modified along the river Areuse Valley: a beautiful valley which is highly attractive to tourists. The village of Boudry is situated in this zone, and the old road used to run through the town. To avoid this, a viaduct and approaches have been constructed. This not only improves the earlier layout, but also greatly facilitates the main road traffic, which no longer interferes with the local vehicles. The viaduct is 500 ms long, and is one of the most important public works recently constructed in Switzerland. The soil did not have a great bearing capacity, and due to the topography, part of the structure, over a distance of 50 ms, rests on a sloping hillside. The viaduct includes various types of spans. Some of them are suitable to accommodate parking spaces underneath, others consist of reinforced concrete beams, and others are made of prestressed concrete members. The main span, 41 ms in length, runs over the river Areuse. In planform the viaduct has a polygonal shape, with rectilinear spans.Con objeto de mejorar la circulación por carretera entre Yverdon y Neuchâtel (Suiza se ha estudiado la modificación del trazado en el trozo correspondiente al valle del río Areuse, pintoresco y con características propias para el turismo. En este valle se encuentra, el poblado de Boudry, cuyo casco urbano era atravesado por la carretera cantonal. Para evitar esta circunstancia se proyectó, después de un detenido estudio, un viaducto y accesos al mismo, que no sólo mejora el trazado primitivo, sino que canaliza el tráfico sin interferir la circulación urbana local. El viaducto, que tiene una longitud total de 500 m, es una de las más importantes obras públicas construidas últimamente en Suiza. El terreno de apoyo no tenía gran capacidad de sustentación, y, dadas las condiciones locales, uno de los tramos se apoya a media ladera, en una

  9. State of the Art of the Development and Application of Anti-Seismic Systems in Europe and Other Countries

    Science.gov (United States)

    Martelli, Alessandro; Forni, Massimo

    2008-07-01

    There are already approximately 5,000 structures in the world, located in over 30 countries, that have been protected by seismic isolation (SI), energy dissipation (ED) and other modern seismic vibration passive control (SVPC) systems. The number of such applications is increasing everywhere more and more. It has been confirmed that, in each country, the extension of the use of the SVPC systems is conclusively influenced by earthquake experience, the availability of specific design rules and the features of those adopted. With regard to application, Japan has consolidated its worldwide leadership, with over 3,000 seismically isolated buildings, many others protected by ED systems and several isolated bridges & viaducts. Second is now the P. R. China, with 610 isolated buildings and 45 with dampers, in addition to numerous isolated bridges & viaducts. The Russian Federation is third for the number of isolated buildings, which are approximately 600. In the USA, due to the very penalizing design code in force for SI of buildings, there are at present only a few new applications of this kind (an overall number of approximately 200 was reported), although the US isolated buildings are mostly quite important, half being retrofits; on the contrary, the use of SI for bridges & viaducts and that of ED for buildings are more popular in the USA. At present (April 2008), Italy (which remains the worldwide leader as regards the application of the SVPC systems to cultural heritage and keeps a key role also as to the number and importance of bridges & viaducts protected by such systems) is at the fifth place, at least for the number of isolated buildings already open to activity: they are 51, besides others protected by other SVPC systems. There, thanks to the new national seismic code (enforced in May 2003), there has been a significant recent increase of building application and design of the SVPC systems. With regard to the use of such systems in other countries, Italy is now

  10. Wastes in the building industry of Ancient Rome

    Directory of Open Access Journals (Sweden)

    В’ячеслав Степанович Волошин

    2015-11-01

    Full Text Available In the article nature of formation of wastes in building industry of Ancient Rome is shown on the example of building of plumbings, viaducts, roads, cult building and buildings. Description of building materials quantitative description of wastes is given. Calculations of energy consumptions and existing system of labour organization in Ancient Rome are brought. The results of calculations of theoretical minimum of wastes’ formation with the use of well-known methodologies are shown. A diagram for the calculation of theoretical minimum of wastes’ formation in building technologies of Ancient Rome is built

  11. Parametric correlations between experimental results and the base isolation, in situ, structural ones

    Directory of Open Access Journals (Sweden)

    Polidor Bratu

    2014-03-01

    Full Text Available The paper addresses the topic of the inconsistency between experimental, laboratory results for antiseismic devices and the dynamic stiffness, internal damping and dissipation parameters through additional devices. The necessary corrections of the stiffness and dissipation (damping parameters will be presented when the antiseismic devices are equipped to satisfy the adequate functions in a complex structural system (buildings, viaducts, bridges under the conditions of seismic motions characteristic to the Romanian territory. In this context, the kinematic excitation method, compared to the dynamic evaluation method of the vibration dissipation capacity, produced by a seismic shock is shown.

  12. Operazioni topografiche per il collaudo di una passerella ciclo - pedonale

    Directory of Open Access Journals (Sweden)

    Giorgio Bezoari

    2013-02-01

    Full Text Available Di norma, il collaudo di ponti, viadotti, cavalcavia, strutture quasi sempre in cemento armato (spesso presollecitato oppure in acciaio (a travi reticolari od a travate piene viene fatto con la ben nota livellazione geometrica di precisione ma se si desidera una analisi dei movimenti 3D si può procedere in altri modi. Surveying for testing a cycle– pedestrian bridge As a rule, the testing of bridges, viaducts, overpasses, almost always reinforced concrete structures (often prestressed or steel (trussgirders or in full is done with the well-known high precision geometric leveling butif you want a 3D movements analysis this can be achieved in other ways.

  13. INFLUENCE OF MOVING LOADS ON CURVED BRIDGES

    OpenAIRE

    Thamer A. Z*, Jabbbar S. A

    2016-01-01

    The behavior of a curved slab bridge decks with uniform thickness under moving load is investigated in this study. Three radii of curvature "R" are used (25, 50 and 75m) along with the straight bridge, R = ∞. The decks are simply supported or clamped along the radial edges and free at the circular edges. The AASHTO[1] standard axle load of the truck H20-44 is used and assumed to move in three track positions on the bridge. The finite element method is employed for the analysis and the ANSYS 5...

  14. Computer Aided Strut-and-Tie Model (CASTM) for the Analysis of RC Deep Beams

    OpenAIRE

    Nabeel A.-M. Al-Bayati A. S. Al-Shaarbaf

    2014-01-01

    Many studies and a lot of research work have been done on the analysis and structural behavior of reinforced concrete deep beams [1, 2 and 3]. In these studies different calculation methods were used. The Beam Method has been used for many years; the Strut-and-Tie Method (STM) is recently included in the Eurocode [4] and has been included in the Canadian Standard for the Design of Concrete Structures[5] since 1984 and the AASHTO LRFD Bridge Specifications [6] since 1994, it is a new concept f...

  15. Una reseña de ensayos de carga no destructivos usados para la evaluación de puentes

    OpenAIRE

    Jáuregui, David

    2001-01-01

    El objetivo principal de este artículo es de proveer un breve repaso de la actividad relacionada con la evaluación experimental de los puentes en los Estados Unidos. Los dos métodos de evaluación de carga aplicados por AASHTO (La Asociación Americana de Oficiales de Carreteras Estatales y Transporte) son presentados incluyendo el esfuerzo permisible (AS) y el factor de carga (LF). Además, son discutidos los detalles básicos de los dos tipos de ensayos de carga más comunes para la evaluación d...

  16. Results of Sediment Sampling and Elutriate Testing at the Proposed Middle Decatur Revetment Shallow Water Habitat Project Site

    Science.gov (United States)

    2014-07-01

    an ongoing catastrophic collapse in the deltaic landscape, primarily wetlands . The hydrologic changes that have caused such damage to South Louisiana... wetlands that captured the nutrients and sediments. 2.3.2 Iowa Nutrient Reduction Strategy The 2008 Gulf Hypoxia Action Plan calls for the 12 states...Depth:Location: Date:Source of Sample:Sample No: Client: Report No.:Project: (X=NO)PERCENTFINERSIZE PASS?SPEC.*PERCENTSIEVE * AASHTO=USCS= Cc= Cu = D10=D15=D30= D50

  17. Combustion of Hazard Division 1.3 M1 Gun Propellant in a Reinforced Concrete Structure

    Science.gov (United States)

    2015-08-01

    Characteristics: • Energy of explosion: • Efficiency of energy t ransfer to kinet ic energy Energy of Explosion PV E= - - y -1 E : Energy of...due to the low potential energy of M1 compared to other gun propellants. The M1 gun propellant was easily accessible from the demilitarization...Manager NAWCWD TM 8742 I-B-10 NAWCWD TM 8742 Adding Value to Energy n~ ASTM C618 I AASHTO M295 Testing of Pomona Terminal Fly Ash SamJ!Ie T’ J!e

  18. Grey cast iron as construction material of bridges from the 18th and 19th century

    Directory of Open Access Journals (Sweden)

    J. Rabiega

    2011-04-01

    Full Text Available Many bridges and railroad viaducts, which have been operated at the western and southern regions of Poland, were erected at the end ofthe 18th or beginning of the 19th century. In recent years they undergo overhauls and renovations requiring familiarity with the construction materials they have been made of. It is necessary for estimation of their load capacity (possible reinforcements and determining their suitability for further utilisation. Among the materials in the old bridges the puddled steels and cast irons predominate. Aim of the work is identification and documentation of microstructure and selected properties of the cast irons used for production of parts for the bridge in Łażany, the Old Mieszczański Bridge in Wrocław, the hanging bridge in Ozimek, as well as the columnar piers of the railroad viaduct in Wrocław. Using the methods of light microscopy and scanning electron microscopy, as well as the results of hardness measurements and chemical analysis, it has been shown that the objects have been built of grey cast iron with flake graphite having the ferritic-pearlitic or pearlitic matrix. The diversification of their chemical analysis resulting from the type, size and geometry of the cast parts was indicated.The tested materials fulfil requirements of the contemporary standards related to grey cast irons of the EN-GJL-100 and EN-GJL-150grades.

  19. Paso elevado, en Manchester – Inglaterra

    Directory of Open Access Journals (Sweden)

    Hayes, J.

    1970-09-01

    Full Text Available This is an urban main traffic connection, running south of the civic centre of Manchester, and facilitates communications in the East West directions. It also links the main motor roads entering the city from the South. It involves a viaduct with two traffic directions, with a total length of 975 m, which runs over several highways and pedestrian footpaths. The article describes the structure of this viaduct and its special features, such as an improved type of prestressed concrete dowels and certain construction problems.Se trata de un paso de enlace urbano, situado al sur del centro cívico de Manchester, que descongestiona el tránsito este-oeste actuando como un distribuidor entre las carreteras principales de entrada desde el sur. Incluye un viaducto de dos calzadas, de unos 975,36 m, que pasa por encima de un conjunto de carreteras al nivel del suelo y de pasos de peatones. El artículo describe la estructura elevada con unas notas sobre los aspectos notables del proyecto, como son: las mejoras introducidas en las dovelas de hormigón pretensado y los problemas que se presentaron durante la construcción.

  20. Los viaductos de acceso al puente de Martigues – Francia

    Directory of Open Access Journals (Sweden)

    Perzo, R.

    1972-11-01

    Full Text Available This article describes the approaches to a large metal bridge 300 m in length. These approaches consist of two viaducts whose decks are continuous beams of prestressed concrete 260 and 315 m long; spans in both viaducts are 45 m long. The cross section is a slab with two 3 m deep ribs; there are no stiffeners, neither between the spans nor over the supports. The two structures have been constructed with spans of 45 m over a self-supporting formwork which has proven very efficient.Se describen los accesos a un gran puente metálico, de 300 m de longitud. Dichos accesos están constituidos por dos viaductos cuyos tableros son vigas continuas, de hormigón pretensado, de 260 y 315 m de longitud; las luces en ambos viaductos son de 45 m. La sección transversal es una losa con dos nervios de 3 m de canto; no existen riostras ni en los vanos ni sobre los apoyos. Las dos estructuras se han construido por tramos de 45 m sobre una cimbra autolanzable, que ha permitido muy buenos rendimientos.

  1. AVALIAÇÃO DOS IMPACTOS DAS OBRAS DE MOBILIDADE URBANA PARA A COPA DO MUNDO FIFA 2014 EM CUIABÁ: O Caso do Viaduto da Universidade Federal de Mato Grosso

    Directory of Open Access Journals (Sweden)

    Andrea Regina Kaneko Kobayashi

    2016-04-01

    Full Text Available The increase of vehicle fleet in recent years has been compromising the organization and flow of traffic in Brazilian cities. Factors such as government incentives to car ownership and the inefficiency of public transport have led people to opt for individual motorized transport, which has caused problems such as congestion, accidents and other traffic conflicts. In order to mitigate such problems, various infrastructure facilities were carried out, mostly prioritizing traditional urban mobility, which seeks to increase traffic speed. However, the sustainable urban mobility has as principles: speed reduction, promotion of reasonable travel times and accessibility to all users. The purpose of this article is to check the impact of urban mobility facilities regarding the 2014 World Cup preparation, which was held in the Metropolitan Region of Cuiabá /MT. The article focuses on sustainable urban mobility from the case study of the viaduct of the Federal University of Mato Grosso. The research is qualitative and exploratory and its data collection is consisted of documental research, observation of the construction, analysis of videos and images and interviews with two professional traffic planning experts. The results showed that the aspects of sustainable urban mobility were not observed in the construction of the viaduct at the Federal University of Mato Grosso, it was identified a lack of planning in the construction and in its surroundings. Other issues related to the lack of transparency regarding the use of funds for the execution and completion of the construction, and the lack of publication of structural design.

  2. Safety Identifying of Integral Abutment Bridges under Seismic and Thermal Loads

    Science.gov (United States)

    Easazadeh Far, Narges; Barghian, Majid

    2014-01-01

    Integral abutment bridges (IABs) have many advantages over conventional bridges in terms of strength and maintenance cost. Due to the integrity of these structures uniform thermal and seismic loads are known important ones on the structure performance. Although all bridge design codes consider temperature and earthquake loads separately in their load combinations for conventional bridges, the thermal load is an “always on” load and, during the occurrence of an earthquake, these two important loads act on bridge simultaneously. Evaluating the safety level of IABs under combination of these loads becomes important. In this paper, the safety of IABs—designed by AASHTO LRFD bridge design code—under combination of thermal and seismic loads is studied. To fulfill this aim, first the target reliability indexes under seismic load have been calculated. Then, these analyses for the same bridge under combination of thermal and seismic loads have been repeated and the obtained reliability indexes are compared with target indexes. It is shown that, for an IAB designed by AASHTO LRFD, the indexes have been reduced under combined effects. So, the target level of safety during its design life is not provided and the code's load combination should be changed. PMID:25405232

  3. Refinement of Strut-and-Tie Model for Reinforced Concrete Deep Beams

    Science.gov (United States)

    Panjehpour, Mohammad; Chai, Hwa Kian; Voo, Yen Lei

    2015-01-01

    Deep beams are commonly used in tall buildings, offshore structures, and foundations. According to many codes and standards, strut-and-tie model (STM) is recommended as a rational approach for deep beam analyses. This research focuses on the STM recommended by ACI 318-11 and AASHTO LRFD and uses experimental results to modify the strut effectiveness factor in STM for reinforced concrete (RC) deep beams. This study aims to refine STM through the strut effectiveness factor and increase result accuracy. Six RC deep beams with different shear span to effective-depth ratios (a/d) of 0.75, 1.00, 1.25, 1.50, 1.75, and 2.00 were experimentally tested under a four-point bending set-up. The ultimate shear strength of deep beams obtained from non-linear finite element modeling and STM recommended by ACI 318-11 as well as AASHTO LRFD (2012) were compared with the experimental results. An empirical equation was proposed to modify the principal tensile strain value in the bottle-shaped strut of deep beams. The equation of the strut effectiveness factor from AASHTTO LRFD was then modified through the aforementioned empirical equation. An investigation on the failure mode and crack propagation in RC deep beams subjected to load was also conducted. PMID:26110268

  4. Refinement of Strut-and-Tie Model for Reinforced Concrete Deep Beams.

    Directory of Open Access Journals (Sweden)

    Mohammad Panjehpour

    Full Text Available Deep beams are commonly used in tall buildings, offshore structures, and foundations. According to many codes and standards, strut-and-tie model (STM is recommended as a rational approach for deep beam analyses. This research focuses on the STM recommended by ACI 318-11 and AASHTO LRFD and uses experimental results to modify the strut effectiveness factor in STM for reinforced concrete (RC deep beams. This study aims to refine STM through the strut effectiveness factor and increase result accuracy. Six RC deep beams with different shear span to effective-depth ratios (a/d of 0.75, 1.00, 1.25, 1.50, 1.75, and 2.00 were experimentally tested under a four-point bending set-up. The ultimate shear strength of deep beams obtained from non-linear finite element modeling and STM recommended by ACI 318-11 as well as AASHTO LRFD (2012 were compared with the experimental results. An empirical equation was proposed to modify the principal tensile strain value in the bottle-shaped strut of deep beams. The equation of the strut effectiveness factor from AASHTTO LRFD was then modified through the aforementioned empirical equation. An investigation on the failure mode and crack propagation in RC deep beams subjected to load was also conducted.

  5. Bicycle guidelines and crash rates on cycle tracks in the United States.

    Science.gov (United States)

    Lusk, Anne C; Morency, Patrick; Miranda-Moreno, Luis F; Willett, Walter C; Dennerlein, Jack T

    2013-07-01

    We studied state-adopted bicycle guidelines to determine whether cycle tracks (physically separated, bicycle-exclusive paths adjacent to sidewalks) were recommended, whether they were built, and their crash rate. We analyzed and compared US bicycle facility guidelines published between 1972 and 1999. We identified 19 cycle tracks in the United States and collected extensive data on cycle track design, usage, and crash history from local communities. We used bicycle counts and crash data to estimate crash rates. A bicycle facility guideline written in 1972 endorsed cycle tracks but American Association of State Highway and Transportation Officials (AASHTO) guidelines (1974-1999) discouraged or did not include cycle tracks and did not cite research about crash rates on cycle tracks. For the 19 US cycle tracks we examined, the overall crash rate was 2.3 (95% confidence interval = 1.7, 3.0) per 1 million bicycle kilometers. AASHTO bicycle guidelines are not explicitly based on rigorous or up-to-date research. Our results show that the risk of bicycle-vehicle crashes is lower on US cycle tracks than published crashes rates on roadways. This study and previous investigations support building cycle tracks.

  6. Live-Load Testing Application Using a Wireless Sensor System and Finite-Element Model Analysis of an Integral Abutment Concrete Girder Bridge

    Directory of Open Access Journals (Sweden)

    Robert W. Fausett

    2014-01-01

    Full Text Available As part of an investigation on the performance of integral abutment bridges, a single-span, integral abutment, prestressed concrete girder bridge near Perry, Utah was instrumented for live-load testing. The live-load test included driving trucks at 2.24 m/s (5 mph along predetermined load paths and measuring the corresponding strain and deflection. The measured data was used to validate a finite-element model (FEM of the bridge. The model showed that the integral abutments were behaving as 94% of a fixed-fixed support. Live-load distribution factors were obtained using this validated model and compared to those calculated in accordance to recommended procedures provided in the AASHTO LRFD Bridge Design Specifications (2010. The results indicated that if the bridge was considered simply supported, the AASHTO LRFD Specification distribution factors were conservative (in comparison to the FEM results. These conservative distribution factors, along with the initial simply supported design assumption resulted in a very conservative bridge design. In addition, a parametric study was conducted by modifying various bridge properties of the validated bridge model, one at a time, in order to investigate the influence that individual changes in span length, deck thickness, edge distance, skew, and fixity had on live-load distribution. The results showed that the bridge properties with the largest influence on bridge live-load distribution were fixity, skew, and changes in edge distance.

  7. Shear Performance of Fiber-Reinforced Cementitious Composites Beam-Column Joint Using Various Fibers

    Directory of Open Access Journals (Sweden)

    Faizal Hanif

    2017-09-01

    Full Text Available Increasing demands of reinforcement in the joint panel are now requiring more effective system to reduce the complicated fabrication by widely used precast system. The joint panel is responsible to keep the load transfer through beam and column as a crucial part in a structural frame that ensures the main feature of the whole structure during earthquake. Since precast system might reduce the joint panel monolithic integrity and stiffness, an innovation by adding fiber into the grouting system will give a breakthrough. The loading test of precast concrete beam-column joints using FRCC (Fiber-Reinforced Cementitious Composites in joint panel was conducted to evaluate the influences of fiber towards shear performance. The experimental factor is fiber types with same volume fraction in mortar matrix of joint panel. Two specimens with Aramid-fiber and PP-fiber by two percent of volume fraction are designed to fail by shear failure in joint panel by reversed cyclic testing method. The comparison amongst those experiment results by various parameters for the shear performance of FRCC beam-column joints using various fibers are discussed. Preceding specimens was using no fiber, PVA fiber, and steel fiber has been carried out. Through the current experimental results and the comparison with previous experiment results, it can be recognized that by using fibers in joint panel was observed qualitatively could prevent crack widening with equitable and smaller crack width, improved the shear capacity by widening the hysteretic area, increased maximum load in positive loading and negative loading, and decreased the deformation rate. Elastic modulus properties of fiber are observed to give the most impact towards shear performance.

  8. Structural Applications of Fibre Reinforced Concrete in the Czech Republic

    Science.gov (United States)

    Kohoutková, A.; Broukalová, I.

    2017-09-01

    The paper presents improvement of function and performance of the precast structural members by using fibre reinforced concrete (FRC) instead of ordinary reinforced concrete and attempts to transfer innovative technologies from laboratory in academic sphere into real industrial production which is cost-effective and brings about savings of labour and material. Three examples of successful technology transfer are shown - application of FRC in an element without common rebar reinforcement, in the element with steel rebar reinforcement and SFRC pre-tensioned structural element. Benefits of FRC utilization are discussed.

  9. Load carrying capacity of shear wall t-connections reinforced with high strength wire ropes

    DEFF Research Database (Denmark)

    Jørgensen, Henrik B.; Bryndom, Thor; Larsen, Michael

    2016-01-01

    Traditionally, U-bar loop connections with keyed joints have been used in vertical shear connections between precast concrete wall elements. However, in the recent years, connections with looped high strength wire ropes instead of U-bar loops have proven to be a much more construction......-friendly solution. The wire ropes have no bending stiffness and therefore allow for an easier vertical installation of the wall elements. During the last 10 – 15 years, a number of shear tests on plane wire rope connections have been carried out. However, to the best knowledge of the authors, tests on wire rope...

  10. Evolution of the Stability Work from Classic Retaining Walls to Mechanically Stabilized Earth Walls

    Directory of Open Access Journals (Sweden)

    Anghel Stanciu

    2008-01-01

    Full Text Available For the consolidation of soil mass and the construction of the stability works for roads infrastructure it was studied the evolution of these kinds of works from classical retaining walls - common concrete retaining walls, to the utilization in our days of the modern and competitive methods - mechanically stabilized earth walls. Like type of execution the variety of the reinforced soil is given by the utilization of different types of reinforcing inclusions (steel strips, geosynthetics, geogrids or facing (precast concrete panels, dry cast modular blocks, metal sheets and plates, gabions, and wrapped sheets of geosynthetics.

  11. Load Carrying Capacity of Shear Wall T-Connections Reinforced with High Strength Wire Ropes

    DEFF Research Database (Denmark)

    Jørgensen, Henrik Brøner; Bryndum, Thor; Larsen, Michael

    2017-01-01

    Traditionally, U-bar loop connections with keyed joints have been used in vertical shear connections between precast concrete wall elements. However, in the recent years, connections with looped high strength wire ropes instead of U-bar loops have proven to be a much more construction......-friendly solution. The wire ropes have no bending stiffness and therefore allow for an easier vertical installation of the wall elements. During the last 10 – 15 years, a number of shear tests on plane wire rope connections have been carried out. However, to the best knowledge of the authors, tests on wire rope...

  12. French Modular Impoundment: Final Cost and Performance Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Drown, Peter [French Development Enterprises, LLC, North Billerica, MA (United States); French, Bill [French Development Enterprises, LLC, North Billerica, MA (United States)

    2017-05-17

    This report comprises the Final Cost and Performance Report for the Department of Energy Award # EE0007244, the French Modular Impoundment (aka the “French Dam”.) The French Dam is a system of applying precast modular construction to water control structures. The “French Dam” is a term used to cover the construction means/methods used to construct or rehabilitate dams, diversion structures, powerhouses, and other hydraulic structures which impound water and are covered under FDE’s existing IP (Patents # US8414223B2; US9103084B2.)

  13. An Alternative Technique for Fabrication of Frameworks in an Immediate Loading Implant Fixed Mandibular Prosthesis

    Directory of Open Access Journals (Sweden)

    André Gustavo Paleari

    2015-01-01

    Full Text Available The oral rehabilitation of edentulous patients with immediate loading has become a safe procedure with high predictability. The success is related to immediate fabrication of a passive fit framework to attach the implants. Based on these considerations, this case report shows an alternative technique for mandibular rehabilitation using implants immediately loaded, where the framework was fabricated using cylinders with internal reinforcement and precast pieces, electrowelding, and conventional welding providing esthetics and function to the patient in a short period of time.

  14. Improving Distribution of Military Programs’ Technical Criteria

    Science.gov (United States)

    1993-08-01

    Macadam Base Course CEGS 02237 02/01/89 Water-Bound Macadem Base Course CEGS 02238 02/01/89 Bituminous-Stabilized Base Crse, Sbbase or Sbgrade CEGS...CEGS 02366 07/01/89 Precast Concrete Piling CEGS 02367 09/01/86 Pressure Injected Concrete Footings CEGS 02371 07/01/89 Auger-Placed Grout Piles CEGS...818-6 02/27170 Grouting Methods & Equipment TM 5-818-7 09/01/83 Foundations in Expansive Soils TM 5-820-1 08/20/87 Surface Drainage Facilities

  15. Los edificios de paneles más altos de España

    Directory of Open Access Journals (Sweden)

    Borsetti, M.

    2009-03-01

    Full Text Available This present article describes the building process of a 484 dwelling complex built with precast RC Load-Bearing wall panels. This building, which reaches 20 storey high, includes too Shops, Offices, 4 garage floors and central services. The main interest of this complex is that it gets to be the highest building made with precast RC load panels in Spain. The building system which has been used is INDAGSA precast system. This is well known due to its approval technical document, which was conceived by the "Eduardo Torroja" Construction Sciences Institute (IETcc (DIT 452. INDAGSA works are also known to be accurate, tide up and clean. Due to these conditions, visits to the site were possible not only for the researchers but for the students of "Industrialization & Prefabrication building systems". This article gives a good description of the industrialized systems involved in the building, trough this we try to show the capacities of precast RC load panel buildings, its advantages and the possibilities for evolution.Este artículo describe el proceso constructivo de un conjunto de 484 viviendas realizadas con paneles prefabricados portantes de hormigón. Dicho conjunto edificatorio, de 20 plantas de altura, se compone de diversos bloques que integran además, locales comerciales, oficinas, trasteros, 4 plantas de garaje e instalaciones comunes. El principal interés de este edificio consiste en haber alcanzado veinte plantas sobre rasante y 4 más de sótano con el sistema constructivo de paneles prefabricados de hormigón INDAGSA; el cual dispone de un Documento de Idoneidad Técnica emitido por el IETcc, con el número DIT 452. Las obras de INDAGSA son conocidas por ser precisas, ordenadas y limpias; debido a estas características, se pudieron establecer visitas no sólo para doctorandos de la ETSAM, sino para estudiantes de la Cátedra de sistemas industrializados y prefabricados. A través de la descripción del sistema constructivo

  16. Concurso para el Proyecto de Construcción de la Variante CV-190 a su paso por el municipio de Figueroles (provincia de Castellón). Alternativa Sur. Concepción estructural y diseño de tableros del puente sobre el río Lucena

    OpenAIRE

    ZHENG LU, JIA YI

    2015-01-01

    [EN] The object of this final degree paper is the design of the deck from a bridge over the Lucena river. This construction is produced because of a detour of the CV-190 road passing by the south of the town of Figueroles, province of Castellón. The need of this new detour is the use of the main side street by heavy traffic with a high danger. This bridge with a total span distance of 144 meters, is resolved with four spans of 36 meters long. The typology chosen for the deck is precast gir...

  17. Method for Bubbledeck Concrete Slab with Gaps

    Directory of Open Access Journals (Sweden)

    Sergiu Călin

    2009-01-01

    Full Text Available The composite slabs are made of BubbleDeck type slab elements with spherical gaps, poured in place on transversal and longitudinal directions. By introducing the gaps leads to a 30...50\\% lighter slab which reduces the loads on the columns, walls and foundations, and of course of the entire building. BubbleDeck slab elements are plates with ribs on two directions made of reinforced concrete or precast concrete with spherical shaped bubbles. These slab elements have a bottom and an upper concrete part connected with vertical ribs that go around the gaps.

  18. Mechanical Properties of Polymer Concrete

    Directory of Open Access Journals (Sweden)

    Raman Bedi

    2013-01-01

    Full Text Available Polymer concrete was introduced in the late 1950s and became well known in the 1970s for its use in repair, thin overlays and floors, and precast components. Because of its properties like high compressive strength, fast curing, high specific strength, and resistance to chemical attacks polymer concrete has found application in very specialized domains. Simultaneously these materials have been used in machine construction also where the vibration damping property of polymer concrete has been exploited. This review deals with the efforts of various researchers in selection of ingredients, processing parameters, curing conditions, and their effects on the mechanical properties of the resulting material.

  19. Development Directions for Various Types of the Light Wood-Framed Structures

    Science.gov (United States)

    Malesza, J.; Baszeń, M.; Miedziałowski, Cz

    2017-11-01

    The paper presents current trends in the development of the wood-framed structures. Authors describe the evolution of the technology of implementation, the production process of precast elements of buildings as well as selected realization on the site of these kinds of structures. The attention has been paid to the effect of implementation phases on construction and erecting technology of the wood-framed structures. The paper draws attention to the importance and enhancement of structural analysis of structures in individual phases of building realization.

  20. Calculation of shear strength of prestressed hollow core slabs by use of plastic theory

    DEFF Research Database (Denmark)

    Hoang, Linh Cao; Jørgensen, Henrik Brøner; Nielsen, Mogens Peter

    2014-01-01

    This paper deals with calculations of the shear capacity of precast, prestressed hollow core slabs. Such slabs are often used as floor systems in Building structures. A common way to produce hollow core slabs is to use the extrusion technique where long strips of slabs are extruded and thereafter...... saw-cut into units with the desirable length. For this reason, hollow core slabs are usually not shear reinforced and anchorage of the prestressing strands has to be established by bond. Hollow core slabs may therefore be more critical to shear and Anchorage failure than ordinary two-way spanning...... reinforced concrete slabs....

  1. Calculation of shear strength of prestressed hollow core slabs by use of plastic theory

    DEFF Research Database (Denmark)

    Hoang, Linh Cao; Jørgensen, H.G.; Nielsen, Mogens Peter

    2014-01-01

    Th is paper deals with calculations of the shear capacity of precast, prestressed hollow core slabs. Such slabs are often used as floor systems in building structures. A common way to produce hollow core slabs is to use the extrusion technique where long strips of slabs are extruded and thereafter...... saw-cut into units with the desirable length. For this reason, hollow core slabs are usually not shear reinforced and anchorage of the prestressing strands has to be established by bond. Hollow core slabs may therefore be more critical to shear and anchorage failure than ordinary two-way spanning...... reinforced concrete slabs....

  2. Transverse Sub-Assemblage Testing of the Inverted-T Bridge System

    OpenAIRE

    Mercer, Matthew Sherman

    2012-01-01

    The inverted-T bridge system is a rapid bridge construction technique that consists of precast inverted-T girders placed adjacent to one another and covered with a cast-in-place deck. This system was first implemented in the U.S. by the Minnesota Department of Transportation (Mn/DOT). This research focuses on improving the constructability of the Mn/DOT system while maintaining the systemâ s structural performance characteristics. To accomplish this goal, five sub-assemblage specimens were ...

  3. A contemporary reinterpretation of Jorn Utzon’s material and technological innovations

    DEFF Research Database (Denmark)

    Egholm Pedersen, Ole; Larsen, Niels Martin; Pigram, Dave

    2014-01-01

    Standardisation and the use of repetitive production processes was a key determinant of achievable forms in the industrial paradigm, impressively displayed in the Sydney Opera House. Today, complex non-repetitive, yet readily achievable, forms can be designed using computational design techniques...... of technology as an integral part of the design process - can give rise to novel structures which take advantage of the new technological situation. Furthering earlier research by the authors[1] [2] [3], a method for constructing a hybrid grid shell structure combining timber and pre-cast concrete elements...

  4. Method for Bubbledeck Concrete Slab with Gaps

    OpenAIRE

    Sergiu Călin; Ciprian Asăvoaie

    2009-01-01

    The composite slabs are made of BubbleDeck type slab elements with spherical gaps, poured in place on transversal and longitudinal directions. By introducing the gaps leads to a 30...50\\% lighter slab which reduces the loads on the columns, walls and foundations, and of course of the entire building. BubbleDeck slab elements are plates with ribs on two directions made of reinforced concrete or precast concrete with spherical shaped bubbles. These slab elements have a bottom and an upper concr...

  5. Fabrication Aware Form-finding

    DEFF Research Database (Denmark)

    Egholm Pedersen, Ole; Larsen, Niels Martin; Pigram, Dave

    2014-01-01

    This paper describes a design and construction method that combines two distinct material systems with fabrication aware form-finding and file-to-factory workflows. The method enables the fluent creation of complex materially efficient structures comprising high populations of geometrically unique...... parts. The first material system employs a novel rotated joint design to allow the structural tuning of quasi-reciprocal timber frame elements fabricated from multi-axis machined plywood sheet stock. The second em-loys discontinuous post-tensioning to assemble unique precast concrete components...

  6. Numerical analysis of negative skin friction on piles in soft clay

    Directory of Open Access Journals (Sweden)

    Yasser M. El-Mossallamy

    2013-04-01

    In this paper, an axisymmetric finite element model was used to simulate, and analyze the pile–soil interaction problem of negative skin friction. The soft soil was simulated by the double hardening soil model, and the pile was described by a linear elastic model. A field case study for two instrumented end bearing driven pipe precast concrete piles in Bangkok soft clay was back analyzed. The various approaches to model the pile element, and load configurations were analyzed, and compared. An extensive parametric study was carried out to investigate the effect of different factors on the dragload value, neutral plane location, slip length, and pile movement.

  7. Preliminary Report on the Effect of Pre-Boring on the Mobilized Friction Capacity of Pile Foundation Hydraulically Jacked into Expansive Soil

    OpenAIRE

    Budi G.S.

    2015-01-01

    Pre-drilling was performed to reduce lateral earth pressure generated by pile foundation hydraulically jacked into expansive soil. Nineteen prestressed-precast spun concrete pile with diameter of 800 mm were penetrated into expansive soil up the depth of 40 m. Pre-drilling with diameter of 700 mm was carried out up to the depth of 12.5 m. Penetration loads required to install the piles, which was displayed on the built-in pressure panel, were recorded every 1 m interval. The load that was con...

  8. Bridging the gap between sustainability, the regulatory, and the recycling of construction and demolition waste in the UAE, with specific reference to the Emirate of Sharjah

    Directory of Open Access Journals (Sweden)

    Bialko Marta

    2017-01-01

    Full Text Available Waste management is currently an inherent part of sustainable construction and, thus, sustainable development. Construction and demolition waste is an issue continuously intensifying in every country. The primary object of this paper is to present issues associated with a gap between sustainable building regulations in the United Arab Emirates, and the recycling facilities such as the Bee’ah facility in Sharjah. Existing construction and demolition waste management has been investigated in terms of available literature as well as for construction sites and the precast concrete factory located in Sharjah.

  9. La incidencia de los hormigones de cemento aluminoso en Madrid

    OpenAIRE

    Macías Hidalgo-Saavedra, Fernando

    1992-01-01

    This article presents, in the first place, the idea coming from the Madrid Town Council (Ayuntamiento de Madrid) to study the dwellings built with high alumina cement, comparing the case of Madrid with those qf other Spanish municipalities. The article also includes one particular case, that of the Vicente Calderón Stadium (Madrid) where we can see what was done after the detection of high alumina cement in prestressed precast beams of the inclined slabs which supported the tiers of the stadi...

  10. Preparation and Properties of Human Hair Keratin Film Lacking Keratin-Associated Proteins

    OpenAIRE

    藤井, 敏弘; 伊藤, 弓子

    2015-01-01

    Human hair keratin film has been used as an alternative to hair samples to evaluate various damages. This film consisted of keratin and keratin-associated proteins (KAPs). The function of KAPs on the molecular constitution of hair and keratin film remains unclear. Recently, we have developed a selective isolation method for keratin and KAPs from human hair. In this study, we proposed a novel keratin film lacking KAPs using the Pre-cast method. The concentration of acetic acid in the casting s...

  11. Numerical Investigation on Detection of Prestress Losses in a Prestressed Concrete Slab by Modal Analysis

    Science.gov (United States)

    Kovalovs, A.; Rucevskis, S.; Akishin, P.; Kolupajevs, J.

    2017-10-01

    The paper presents numerical results of loss of prestress in the reinforced prestressed precast hollow core slabs by modal analysis. Loss of prestress is investigated by the 3D finite element method, using ANSYS software. In the numerical examples, variables initial stresses were introduced into seven-wire stress-relieved strands of the concrete slabs. The effects of span and material properties of concrete on the modal frequencies of the concrete structure under initial stress were studied. Modal parameters computed from the finite element models were compared. Applicability and effectiveness of the proposed method was investigated.

  12. Performance of Hydrophobisation Techniques in Case of Reinforced Concrete Structures

    Science.gov (United States)

    Błaszczyński, Tomasz; Osesek, Mateusz; Gwozdowski, Błażej; Ilski, Mirosław

    2017-10-01

    Concrete is, unchangeably, one of the most frequently applied building materials, also in the case of bridges, overpasses or viaducts. Along with the aging of such structures, the degradation of concrete, which may accelerate the corrosion of reinforcing steel and drastically decrease the load-bearing capacity of the structure, becomes an important issue. The paper analyzes the possibilities of using deep hydrophobisation in repairing reinforced concrete engineering structures. The benefits of properly securing reinforced concrete structures from the damaging effects of UV radiation, the influence of harmful gases, or progression of chlorine induced corrosion have been presented, especially in regards to bridge structures. The need to calculate the costs of carrying out investments along with the expected costs of maintaining such structures, as well as the high share of costs connected with logistics, has also been indicated in the total costs of repair works.

  13. Vibration monitoring of long bridges and their expansion joints and seismic devices

    Directory of Open Access Journals (Sweden)

    Islami Kleidi

    2015-01-01

    Full Text Available This paper presents a number of recently installed Structural Health Monitoring (SHM systems: a on a 2km double suspension bridge; b on a long railway viaduct that has experienced cracking; and c on a steel arch bridge in a seismically active area. Damage detection techniques have been applied based on high-frequency measurements of vibrations, pressure and strain, enabling a proper understanding of the structures’ behaviour to be gained. The diverse range of applications presented, designed in collaboration with structure owners and design engineers, includes damage detection on expansion joints of suspension bridges, crack analysis and correlation with accelerations of high-speed trains, and high-frequency performance monitoring of seismic devices. These case studies, based on both static and dynamic approaches, demonstrate the usefulness and ease of use of such systems, and the enormous gains in efficiency they offer.

  14. Intercambio direccional en roseta – Suiza

    Directory of Open Access Journals (Sweden)

    Guisan, François

    1964-11-01

    Full Text Available This crossing, at Ecublens, Switzerland, involves five viaducts. The number of roads that the Lausanne-Berne motorway had to cross presented a difficult problem, since technical, aesthetic and economic questions had to be considered, all on a complex scale. As the soil was not suitable to support heavy structures, it was decided to build five viaducts, each providing a traffic route. Some of these viaducts cross each other at three levels. The viaducts consist of box girder sections, joined together to form continuous beams. The two central piles of each section are rigid, to withstand wind forces, and the others are hinged at the top and bottom. The sections are separated by dilatation joints, fitted with a metal attachment, which provides continuity for the pavement, and allows for a relative displacement of 16 cm. Some of the supports were placed on pile foundations, to overcome the weak bearing strength of the subsoil. One of the road sections did not have any rigid central supports, and this arrangement was chosen for aesthetic reasons.El intercambio direccional en roseta, de Ecublens (Suiza, está constituido por un conjunto de cinco viaductos. La multiplicidad de vías que debía salvar la autopista Lausana-Berna planteó un problema importante, ya que era preciso tener en cuenta factores de tipo técnico, en lo que respecta a las obras de fábrica; estéticos, en cuanto a armonía con el paisaje local, y económicos. Técnicamente, y teniendo en cuenta que las condiciones del terreno eran poco apropiadas para levantar obras pesadas, la solución adoptada consiste, en esencia, en cinco viaductos que constituyen otros tantos pasos, algunos de ellos intermedios, es decir, situados entre dos vías: una superior y otra inferior. Cada uno de los pasos se ha subdividido en varios tramos de viga cajón continua. Las dos pilas centrales de cada tramo son rígidas, para poder absorber los efectos del viento; las demás están articuladas en la

  15. Metro as an example of an urban rail system. Four case studies from Europe

    Directory of Open Access Journals (Sweden)

    Anna FRASZCZYK

    2014-10-01

    Full Text Available Underground, tube, subway or metro are common expressions used to describe a rapid transit system serving urban areas. Such a system uses dedicated rail corridors, can run underground or overground, and often includes tunnels and viaducts. Although there are 148 cities in the world with metro systems, each system is different, in terms of layout, length, capacity, etc., as it serves different geographical and socio-economical areas. In this context, the paper presents four European metro systems (Sofia, Warsaw, Lisbon, and Tyne and Wear, introduces the systems dimensions, rolling stock and ticketing strategies and compares similarities and differences between the systems. The analyses suggest a number of recommendations and improvements, which if implemented, could benefit other metro systems in Europe and beyond.

  16. Comparison and calibration of numerical models from monitoring data of a reinforced concrete highway bridge

    Directory of Open Access Journals (Sweden)

    R. G. M. de Andrade

    Full Text Available The last four decades were important for the Brazilian highway system. Financial investments were made so it could expand and many structural solutions for bridges and viaducts were developed. In parallel, there was a significant raise of pathologies in these structures, due to lack of maintenance procedures. Thus, this paper main purpose is to create a short-term monitoring plan in order to check the structural behavior of a curved highway concrete bridge in current use. A bridge was chosen as a case study. A hierarchy of six numerical models is shown, so it can validate the bridge's structural behaviour. The acquired data from the monitoring was compared with the finest models so a calibration could be made.

  17. Los viaductos de Chillón Suiza

    Directory of Open Access Journals (Sweden)

    Hofer, Roland

    1970-02-01

    Full Text Available The articles describes in detail the problems involved in the construction of this important motor road in the Alto Leman region, which is characterised by its difficult topography and density of population. Details are also given about the design of the viaduct, which runs along the mountain slope and overcomes many difficult geographical features, whilst satisfying strict aesthetic, technical and low cost conditions.El artículo explica detalladamente los problemas que ha originado la construcción de esta importante autopista a la región del Alto Leman, caracterizada por su accidentada topografía y gran densidad demográfica. Igualmente se describe la solución adoptada de viaducto con trazado a media ladera, venciendo diversas e interesantes dificultades y cumplimentando todas las exigencias estéticas, técnicas y económicas impuestas.

  18. Description of a Composed Seismic Isolation System for Bridge Structures

    Directory of Open Access Journals (Sweden)

    Fănel Dorel Șcheaua

    2015-09-01

    Full Text Available From the design stage of a specific structural project, achieving a high level of safety is desired for structures, necessary to withstand dynamic actions that could have destructive effects on the resistant structure. In order to obtain the optimum level of safety against dynamic actions different types of isolation systems are placed into the structural system. The most commonly isolation method used is the base isolation method through which a disconnection between foundation and superstructure can be achieved. The isolation method presented uses special mechanical systems which are able to consume an amount from dynamic actions energy through their action. This study presents a base isolation method for building structures along with an overview of the different system solutions used to achieve the desired objective: ensuring a high level of safety for a bridge or viaduct structural type during a seismic event.

  19. Development of Flexible Link Slabs using Ductile Fiber Reinforced Concrete

    DEFF Research Database (Denmark)

    Lárusson, Lárus Helgi

    -induced deflections of adjacent spans. Mechanical expansion joints, commonly used between simply supported spans in bridge structures, tend to deteriorate and require significant maintenance activities. Deterioration is often caused by ingress of water and chlorides into the joints, which leads to corrosion......Civil engineering structures with large dimensions, such as multi-span bridges, overpasses and viaducts, are typically equipped with mechanical expansion joints. These joints allow the individual spans of the structure to undergo unrestrained deformations due to thermal expansions and load...... of the joint and spalling of the surrounding concrete, and more importantly to corrosion of the bridge substructure including girders and bearings. Deterioration and the resulting rehabilitation and maintenance needs of such structures constitute a significant infrastructure deficiency. In this study...

  20. The Nimitz Freeway Collapse

    Science.gov (United States)

    Feldman, Bernard J.

    2004-10-01

    One of the most tragic sights created by the Loma Prieta earthquake of Oct. 17, 1989, was the collapse of the double-deck Nimitz Freeway (the Cypress Street Viaduct on Interstate 880) just south and east of the San Francisco-Oakland Bay Bridge in Oakland. Along a 1.4-km north-south stretch, the upper deck of the freeway fell on top of the lower deck of the freeway, killing 42 motorists (see Fig. 1). Even though the earthquake occurred during rush hour (5:04 p.m.), traffic was extremely light that day because the third game of the World Series between the Oakland Athletics and the San Francisco Giants was about to begin and many commuters were already at home in front of their television sets.

  1. Modeling spatial variations of black carbon particles in an urban highway-building environment.

    Science.gov (United States)

    Tong, Zheming; Wang, Yan Jason; Patel, Molini; Kinney, Patrick; Chrillrud, Steven; Zhang, K Max

    2012-01-03

    Highway-building environments are prevalent in metropolitan areas. This paper presents our findings in investigating pollutant transport in a highway-building environment by combing field measurement and numerical simulations. We employ and improve the Comprehensive Turbulent Aerosol Dynamics and Gas Chemistry (CTAG) model to simulate the spatial variations of black carbon (BC) concentrations near highway I-87 and an urban school in the South Bronx, New York. The results of CTAG simulations are evaluated against and agree adequately with the measurements of wind speed, wind directions, and BC concentrations. Our analysis suggests that the BC concentration at the measurement point of the urban school could decrease by 43-54% if roadside buildings were absent. Furthermore, we characterize two generalized conditions in a highway-building environment, i.e., highway-building canyon and highway viaduct-building. The former refers to the canyon between solid highway embankment and roadside buildings, where the spatial profiles of BC depend on the equivalent canyon aspect ratio and flow recirculation. The latter refers to the area between a highway viaduct (i.e., elevated highway with open space underneath) and roadside buildings, where strong flow recirculation is absent and the spatial profiles of BC are determined by the relative heights of the highway and buildings. The two configurations may occur at different locations or in the same location with different wind directions when highway geometry is complex. Our study demonstrates the importance of incorporating highway-building interaction into the assessment of human exposure to near-road air pollution. It also calls for active roles of building and highway designs in mitigating near-road exposure of urban population.

  2. Modeling spatial variations of black carbon particles in an urban highway-buildings environment

    Science.gov (United States)

    Tong, Zheming; Wang, Yan; Patel, Molini; Kinney, Patrick; Chrillrud, Steven; Zhang, K. Max

    2011-01-01

    Highway-building environments are prevalent in metropolitan areas. This paper presents our findings in investigating pollutant transport in a highway-building environment by combing field measurement and numerical simulations. We employ and improve the Comprehensive Turbulent Aerosol Dynamics and Gas Chemistry (CTAG) model to simulate the spatial variations of black carbon (BC) concentrations near highway I-87 and an urban school in the South Bronx, New York. The results of CTAG simulations are evaluated against and agree adequately with the measurements of wind speed, wind directions and BC concentrations. Our analysis suggests that the BC concentration at the measurement point of the urban school could decrease by 43–54% if roadside buildings were absent. Furthermore, we characterize two generalized conditions in a highway-building environment, i.e., highway-building canyon and highway viaduct-building. The former refers to the canyon between solid highway embankment and roadside buildings, where the spatial profiles of BC depend on the equivalent canyon aspect ratio and flow recirculation. The latter refers to the area between a highway viaduct (i.e., elevated highway with open space underneath) and roadside buildings, where strong flow recirculation is absent and the spatial profiles of BC are determined by the relative heights of the highway and buildings. The two configurations may occur at different locations or in the same location with different wind directions when highway geometry is complex. Our study demonstrates the importance of incorporating highway-building interaction into the assessment of human exposure to near-road air pollution. It also calls for active roles of building and highway designs in mitigating near-road exposure of urban population. PMID:22084971

  3. Perilaku dan Kekuatan Sambungan Kolom pada Sistem Beton Pracetak

    Directory of Open Access Journals (Sweden)

    Rudi Yuniarto Adi

    2015-10-01

    Full Text Available At this time, the architecture and design of the existing floor plan often changes according to the needs and tastes of the owner in accordance with the changing times. This research was conducted as precast concrete structures become even more important with the increase in man's desire to change the design of his home without spending enormous cost. This study aims to investigate the stiffness and study the behavior of precast concrete between monolith column with no connections and the column with connection. The connection used is dry joint using a plate and screw nut. The results obtained are the stiffness of the test specimen column with no connections is smaller than the test object column with connection. The modulus of elasticity of the column without a connection greater than the column with connection. Cracks that occurred in the test object columns without connection occurs faster than the test object columns with connection and both, flexural cracks occur first and then cracked in shear.

  4. Development of an accelerated test for Internal Sulfate Attack study

    Directory of Open Access Journals (Sweden)

    Khelil Nacim

    2014-04-01

    Full Text Available Internal Sulfate Attack (ISA is a pathology that occurs under certain conditions in concrete having undergone heating above 70 °C at early age (through heating in pre-casting industry or due to hydration in large concrete parts. This reaction deemed very slow, numerous methods to speed up reactions leading to delayed ettringite formation have been developed. These methods are all based on the material damage. Another type of test is currently under development. It is based on rehabilitation techniques such as electrochemical chloride extraction (ECE in order to accelerate the leaching of alkalis that could be one of the triggers of the pathology. The study presented in this paper focused on concrete specimens prepared from cement (CEM I 52.5 N enriched with Na2SO4. These concretes have undergone a heat treatment typical of those used in precast plants (up to 24 hours with a maximum temperature of 80 °C. Various paths were explored for the development of the accelerated test. The first results showed that it was necessary to use a removable titanium anode ruthenium anode instead of stainless steel embedded in the concrete. Then tests with de-ionized water as the solute to the cathode did not accelerate the onset of expansions. The experiment has been modified and potassium carbonate was added to the solution. This modification didn’t show any significant improvement, and other experiments are being carried out to explain this result.

  5. Nonlinear Analysis of Spliced Continuous RC Girders Strengthened with (CFRP Laminates using ANSYS

    Directory of Open Access Journals (Sweden)

    Ammar Yasir Ali

    2016-03-01

    Full Text Available This paper presents the details of the finite element analysis of spliced continuous reinforced concrete girders. Five spliced continuous girders and one non-spliced continuous girder were analyzed using the ANSYS program. Each spliced girder consisted of three precast segments spliced at two cast-in-place joints at the inflection points, using splices of hooked dowels. Three spliced girders were strengthened using different schemes of the carbon fiber reinforced polymer (CFRP laminates. The concrete was modeled using (SOLID65 eight-node brick element and the steel reinforcement was modeled discretely using (LINK8 spar element. The straight parts of the spliced bars were modeled using discrete representation with interface elements using (COMBIN39 elements to represent the bond-slip behavior while the hooked part of each spliced bar was replaced by a single spring element. The CFRP laminates were modeled using (SHELL41 shell element. The interfaces between the precast concrete segments and the joints were modeled using CONTAC52 interface elements in conjunction with vertical spring elements to represent the dowel action of the steel bars that crossing the interfaces. The ANSYS model succeeded to an acceptable degree in predicting the structural behavior of the analyzed spliced girders with average of differences of about 6% between the predicted and experimental ultimate load.

  6. Recycling of electric arc furnace (EAF dust for use in steel making process

    Directory of Open Access Journals (Sweden)

    José Alencastro de Araújo

    2014-07-01

    Full Text Available The EAF dust is listed as hazardous waste from specific source, K061, according to ABNT 10004:2004 and constitutes one of the major problems of electrical steel plant. This work suggests recycling of the EAF dust by sintering of a composite, pre-cast agglomerate (PCA consisting of EAF dust agglomerate to coke particles, mill scale and ceramic fluorite into pellets. The work was divided into three stages, in the first stage the technical viability of using only solid waste industrial to produce a PCA was observed, in the second phase, the main effects between the components of the PCA to obtain the optimal formulation was tested. In the third phase the intensity of the variables, coke and fluorite ceramics, for removing zinc of PCA was checked. Every stage was chemically analyzed by X-ray fluorescence spectrometer and X-ray diffraction. The first two stages of the production PCA were carried out in a pilot plant sintering downstream and the third phase in a pilot plant upstream. As a result of the process two by-products were obtained, the pre-cast agglomerated, PCA, with total iron content exceeding 70%, object of the process of sintering and zinc dust, containing more than 50% zinc resulting from volatilization of this metal during the sintering process and collected by bag filter. In addition, approximately 90% of lead and cadmium contained in the initial EAF dust was extracted.

  7. Análise sobre a Dimensão Oferta no Contexto Inovação dentro do Setor de Estruturas Pré-moldadas na Grande Natal

    Directory of Open Access Journals (Sweden)

    Marcela C. Campos Capeleiro

    2013-07-01

    Full Text Available This paper aims to investigate, through a qualitative approach, the innovation practices of micro and small enterprises in precast structures in the region of Natal, RN, using the conceptual dimension of Radar Innovation applied to these companies. Through these dimensions evaluated the degree of innovation of enterprises. Among the ten dimensions broached by radar, there is offer dimension, which refers to the innovation of products offered by the company to the market. For elaboration of the analysis, was previously developed a theoretical discussion of the concepts of innovation, sustainability and the current national scenario sector precast structures. Next was achieved a research exploratory qualitative with four companies of segment, that are served by the program Agentes Locais de Inovação of Rio Grande do Norte. With the application of the research was possible to see that there is a broad field of innovation can be worked in these firms, given that it was observed that they do not have a culture of innovation, innovate only by necessity. Also noticed was the gap between higher education institutions and private companies. We conclude that entrepreneurs possess broad concepts about innovation, which facilitates the stimulation of innovation culture, whether by government, educational institutions or private companies

  8. Model Simulasi Risiko Rantai Pasok Material Proyek Konstruksi Gedung

    Directory of Open Access Journals (Sweden)

    Jati Utomo Dwi Hatmoko

    2017-07-01

    Full Text Available Delays related to materials are one of main problems of construction project. An effective supply chain management has a significant role in preventing this type of delay. The aim of this research is develop risk simulation model of construction supply chain in buildings. The materials include steel bars, steel profiles, formwork, and precast concrete, as they are considered the main building material. The supply chain risks are classified from supply, control, process, and demand sides. Monte Carlo simulation has been performed using Cristal Ball software. Risk identification was done through literature review, site observation, and interviews with 29 contractor personnel  working for nine building projects. The simulation results show that the minimum, maximum, and most frequent delays (in days, as follows: steel bars (2.20. 17.05, 11.24; steel profiles (2.12, 15.10, 9.75, formwork (1.79, 16.04, 10.45, precast concrete (1.76, 15.61, 10.24.  The sensitivity analysis shows that delay due to change order from client is the most sensitive for  steel bars, steel profiles, and formwork of 25.5%, 37.4%, dan 17%, respectively. The results of this research is useful for contractors and owners who can use them as a guidance in identifying, predicting, and mitigating supply chain risks for a successful project.

  9. Experimental Study on Forecasting Mathematical Model of Drying Shrinkage of Recycled Aggregate Concrete

    Directory of Open Access Journals (Sweden)

    Yuanchen Guo

    2012-01-01

    Full Text Available On the basis of basic law in AASHTO2007 model, the forecasting mathematical model of drying shrinkage of recycled aggregate concrete (RAC is established by regression analysis and experimental study. The research results show that (1 with the replacement rate of RCA increases, the drying shrinkage value of RAC increases; this trend is even more obvious in the early drying time. (2 The addition of fly ash can inhibit the drying shrinkage of RAC, but the effect is not very obvious. Specifically, the addition of fly ash will increase the shrinkage to some extent when the mixing amount is 20%. (3 The addition of expansive agent can obviously inhibit the shrinkage of RAC; the inhibition affection is better than that of fly ash. (4 The forecasting mathematical models of drying shrinkage of RAC established in this paper have high accuracy and rationality according to experiment validation and error analysis.

  10. Strategic sensor locations of FPR bridge decks

    Science.gov (United States)

    Wu, Hwai-Chung; Warnemuende, Kraig; Yan, An; Mu, Bin

    2003-07-01

    Advanced fiber-reinforced polymer composite (FRP) has been increasingly used in bridge deck to replace concrete or steel. A FRP bridge deck can be designed to meet AASHTO HS-25 load requirements. FRP decks have many advantages over the conventional reinforced concrete or steel decks owing to their lightweight, high strength and corrosion resistance. However, such new deck system requires extensive monitoring to ensure its designed performance before its widespread acceptance by the bridge community. For inspection and evaluation purpose, a proper monitoring system consisting of various kinds of sensors installed in the FRP deck is critical. This paper provides a framework for designing an efficient monitoring system. The strategic sensor locations are identified based on the stress analysis of the FRP deck.

  11. Probabilistic model of bridge vehicle loads in port area based on in-situ load testing

    Science.gov (United States)

    Deng, Ming; Wang, Lei; Zhang, Jianren; Wang, Rei; Yan, Yanhong

    2017-11-01

    Vehicle load is an important factor affecting the safety and usability of bridges. An statistical analysis is carried out in this paper to investigate the vehicle load data of Tianjin Haibin highway in Tianjin port of China, which are collected by the Weigh-in- Motion (WIM) system. Following this, the effect of the vehicle load on test bridge is calculated, and then compared with the calculation result according to HL-93(AASHTO LRFD). Results show that the overall vehicle load follows a distribution with a weighted sum of four normal distributions. The maximum vehicle load during the design reference period follows a type I extremum distribution. The vehicle load effect also follows a weighted sum of four normal distributions, and the standard value of the vehicle load is recommended as 1.8 times that of the calculated value according to HL-93.

  12. Reliability and construction control

    Directory of Open Access Journals (Sweden)

    Sherif S. AbdelSalam

    2016-06-01

    Full Text Available The goal of this study was to determine the most reliable and efficient combination of design and construction methods required for vibro piles. For a wide range of static and dynamic formulas, the reliability-based resistance factors were calculated using EGYPT database, which houses load test results for 318 piles. The analysis was extended to introduce a construction control factor that determines the variation between the pile nominal capacities calculated using static versus dynamic formulae. From the major outcomes, the lowest coefficient of variation is associated with Davisson’s criterion, and the resistance factors calculated for the AASHTO method are relatively high compared with other methods. Additionally, the CPT-Nottingham and Schmertmann method provided the most economic design. Recommendations related to a pile construction control factor were also presented, and it was found that utilizing the factor can significantly reduce variations between calculated and actual capacities.

  13. An Experimental Study on the Wind-Induced Response of Variable Message Signs

    Directory of Open Access Journals (Sweden)

    Debbie Meyer

    2017-11-01

    Full Text Available Variable message sign (VMS systems are widely used in motorways to provide traffic information to motorists. Such systems are subjected to wind-induced structural vibration that can lead to damage due to fatigue. The limited information that is available on the safe wind design of VMS motivated a large scale testing that was conducted at the wall of wind (WOW Experimental Facility at Florida International University (FIU. One of the objectives of the present study was to experimentally assess the wind-induced force coefficients on VMS of different geometries and utilize these results to provide improved design guidelines. A comprehensive range of VMS geometries was tested, and mean normal and lateral force coefficients, in addition to the twisting moment coefficient and eccentricity ratio, were determined using the measured data for each model, for wind directions of 0° and 45°. The results confirmed that the mean drag coefficient on a prismatic VMS is smaller than the value of 1.7 suggested by American Association of State Highway and Transportation Officials (AASHTO. An alternative to this value is presented in the form of a design matrix with coefficients ranging from 0.98 to 1.28, depending on the aspect and depth ratio of the VMS. Furthermore, results indicated that the corner modification on a VMS with chamfered edges demonstrated a reduction in the drag coefficient compared to sharper edges. Finally, the dynamic loading effects were considered by evaluating the gust effect factor, using the ASCE 7 formulations, for various VMS weights and geometries. The findings revealed a wide range of possible gust effect factors, both above and below the current AASHTO specification of 1.14. Future research may include different geometries of VMS and a wider range of wind directions.

  14. Prestressing Concrete with CFRP Composites for Sustainability and Corrosion-Free Applications

    Directory of Open Access Journals (Sweden)

    Belarbi A.

    2018-01-01

    Full Text Available Advancement in material science has enabled the engineers to enhance the strength and long-term behavior of concrete structures. The conventional approach is to use steel for prestressed bridge girders. Despite having good ductility and strength, beams prestressed with steel are susceptible to corrosion when subjected to environmental exposure. The corrosion of the prestressing steel reduces load carrying capacity of the prestressed member and result in catastrophic failures. In the last decades, more durable composite materials such as Aramid Fiber Reinforced Polymer (AFRP, Glass Fiber Reinforced Polymer (GFRP and Carbon Fiber Reinforced Polymer (CFRP have been implemented in concrete structures as a solution to this problem. Among these materials, CFRP stands out as a primary prestressing reinforcement, which has the potential to replace steel and provide corrosion free prestressed bridge girders. Despite its promise, prestressing CFRP has not frequently been used for bridge construction worldwide. The major contributing factor to the lack of advancement of this promising technology in the United States (U.S. is the lack of comprehensive design specifications. Apart from a limited number of guides, manuals, and commentaries, there is currently no standard or comprehensive design guideline available to bridge engineers in the U.S. for the design of concrete structures prestressed with CFRP systems. The main goal is to develop design guidelines in AASHTO-LRFD format for concrete bridge girders with prestressing CFRP materials. The guidelines are intended to address the limitation in current AASHTO-LRFD Bridge Design Specifications which is applicable for prestressed bridge girders with steel strands. To accomplish this goal, some of the critical parameters that affect the design and long-term behavior of prestressed concrete bridge girders with prestressing CFRP systems are identified and included in the research work. This paper presents

  15. Sistema integrado para toma de decisiones en el diseño de estructuras de hormigón

    Directory of Open Access Journals (Sweden)

    Armengou, J.

    2012-09-01

    Full Text Available This paper presents a methodology to analyze decisions in the design of concrete structures. Specifically, we propose a multi-criteria approach to assess the value implications of precast concrete technologies versus in-situ concrete solutions. First, we emphasize the importance of careful decision-making in early stages of construction projects to enhance customer value. Second, we present a decisionmaking methodology that uses fuzzy logic to represent and synthesize information about risk-return tradeoffs in the different kinds of variables involved in the evaluation of a project’s value. To illustrate, we use our methodology to analyze precast vs. in-situ solutions in the design of drainage structures. The results of our analysis point at precast solutions as the most desirable design choice in this setting, and highlight the importance of value analysis in early stages of construction projects.

    El presente artículo hace una breve reflexión sobre las alternativas in situ y prefabricadas para estructuras de hormigón, justificando la necesidad de profundizar en métodos multicriterio como ayuda a la toma de decisiones. Manifiesta la trascendencia de la calidad en las decisiones más allá de este ámbito concreto, así como su influencia en la mayor eficiencia de las obras. Presenta luego un sistema de ayuda a la toma de decisiones basado en matemática difusa, que considera el valor de cada alternativa contemplando el riesgo inherente. Para ilustrarlo desarrolla un ejemplo aplicado a pasos inferiores que pueden resolverse mediante prefabricación o in situ. Efectuándolo por completo, llega a dos conclusiones principales: la bondad de la herramienta presentada y cómo la solución prefabricada, en este caso, aporta mayor valor. Concluye también que todo buen gestor debe plantearse su toma de decisión desde los inicios de cualquier proyecto, empleando herramientas como la presentada.

  16. Puentes de la autopista de Madrid a La Coruña

    Directory of Open Access Journals (Sweden)

    Fernández Casado, C.

    1967-11-01

    Full Text Available The fortunate circumstance that an urgent plan was approved to transform the road to La Coruña into a motor road, over a distance which was already being converted into a double lane road, led to the standardised design of the ten viaducts over the motor road, between Las Rozas and Villalba. The consequence of the above requirements, and much careful thought, are the viaducts which now emerge from constrasting landscape of plain and mountain, between Madrid and the nearby Sierra. The road ascends, following the natural topography and the positioning of the villages, and also taking advantage of parts of old Roman roads, cattle lanes, and later roads built in the times of the Austrias, the Bourbons and for the use of horse carriages. Actually, by a logical coincidence, the viaducts are sited at the cross roads of this old road pattern. The traffic and the geotechnical conditions are fairly similar for all the viaducts, and this factor was reinforced by the present tendency to standardise the design of Spanish motor roads. But in contrast to this there is the need to attend to the particular requirements of each case: a consideration that perhaps has deserved even more care than the first one. As a result of these contrasting conditions, the underpasses, three of the motor way and another of the railway, have been standardised: the same design has been used on two occasions (prestressed slabs at Pinar de Las Rozas and at Peñascales, and in addition, this design could be repeated for any other motor road or for any other two level crossing, when the lower one is a railway or secondary road. On the other hand, on the overpasses standardisation has not been possible: althought the basic pattern has been the same in all the structures, the detailed construction is different in each. The overpasses are more important projects than the underpasses, and in addition, their detailed adaptation to the site has a greater influence on the total project

  17. The effects of moisture and temperature variations on the long term durability of polymer concrete

    DEFF Research Database (Denmark)

    Barbosa, Ricardo; Hansen, Kurt Kielsgaard; Grelk, Bent

    2013-01-01

    The use of polymer concrete to precast products in construction presents normally many advantages compared to traditional concrete. Higher strength, lower permeability, shorter curing periods, better chemical resistances and a better durability is normally predicated, however this is a research...... field where published data are scarce. Durability and constantly high and good physical properties are some of the most important properties of the materials used in the building industry. Thermal durability, i.e. the ability of a material to retain its original physical-mechanical properties during...... and after exposure to different thermal conditions is very important. In this paper, an experimental study concerning the influence of temperature and moisture in cyclic conditions on the durability of polymer concrete based on an unsaturated polyester resin is described and the results are presented...

  18. Static, Fire and Fatigue Tests of Ultra High-Strength Fibre Reinforced Concrete and Ribbed Bars

    DEFF Research Database (Denmark)

    Hansen, Lars Pilegaard; Heshe, Gert

    2001-01-01

    A new building system has been developed during the last 10 years. This new system consists of a column / slab system with 6 x 6 m distance between the columns. The slabs are precast concrete elements of size 2.9 x 5.9 m connected through joints of ultra high strength fibre reinforced concrete...... - Densit Joint Cast ®. Also the connections between the columns and the slabs are made of this very strong concrete material. The paper describes some of the static tests carried out as well as some fire tests. Further, 2 chapters deal with some fatigue tests of the reinforcing bars as well as some fatigue...... tests of tensile specimens consisting of reinforcing bars embedded in Densit Joint Cast ®. The objective of these fatigue tests is to show that the system / connection can presumably also be used in structures subjected to dominant time- varying loads and thus for example in earthquake regions....

  19. Efficiency of fiber reinforced concrete application in structures subjected to dynamic effects

    Directory of Open Access Journals (Sweden)

    Morozov Valeriy Ivanovich

    2014-03-01

    Full Text Available Fiber reinforced concretes possess high strength under dynamic loadings, which include impact loads, thanks to their high structural viscosity. This is the reason for using them in difficult operating conditions, where increasing the performance characteristics and the structure durability is of prime importance, and the issues of the cost become less significant. Applying methods of disperse reinforcement is most challenging in case of subtle high-porous materials on mineral binders, for example foamed concrete. At the same time, the experiments conducted in Russia and abroad show, that also in other cases the concrete strength resistance several times increases as a result of disperse reinforcement. This doesn't depend on average density of the concrete and type of fiber used. In the article the fibre reinforced concrete impact resistance is analysed. Recommendations are given in regard to fibre concrete application in manufacture of monolithic floor units for industrial buildings and precast piles.

  20. Development of bufferless gel electrophoresis chip for easy preparation and rapid DNA separation.

    Science.gov (United States)

    Oleksandrov, Sergiy; Aman, Abdurazak; Lim, Wanyoung; Kim, Younghee; Bae, Nam Ho; Lee, Kyoung G; Lee, Seok Jae; Park, Sungsu

    2017-09-27

    This work presents a handy, fast, and compact bufferless gel electrophoresis chip (BGEC), which consists of precast agarose gel confined in a disposable plastic body with electrodes. It does not require large volumes of buffer to fill reservoirs, or the process of immersing the gel in the buffer. It withstands voltages up to 28.4 V/cm, thereby allowing DNA separation within 10 min with a similar separation capability to the standard gel electrophoresis. The results suggest that our BGEC is highly suitable for in situ gel electrophoresis in forensic, epidemiological settings and crime scenes where standard gel electrophoresis equipment cannot be brought in while quick results are needed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Report on the international conference and bridge inspection in Singapore and Hong Kong. `97 Singapore and Hong Kong inspector group; Singapore Hong Kong no kokusai kaigi to kyoryo shisatsu hokoku. `97 Singapore Hong Kong shisatsudan

    Energy Technology Data Exchange (ETDEWEB)

    Abe, N.; Arai, H.; Shiota, R.; Takagaki, T.; Mori, T.

    1997-07-31

    The 4th International Symposium on Noteworthy Development in Prestressing and Precasting was held in Singapore in July 1997. The `97 Singapore and Hong Kong inspector group was organized by the Japan Prestressed Concrete Engineering Association to participate the symposium and inspect some bridges. The symposium consisted of reading of 17 presented papers (including questions and answers) related to introduction of PC and PCa structures of every country, PCa void lower slab for building floors, bridge, PCa joint, PCa residence, earthquake resistance, and structure analysis. Suzuki`s keynote address `Development and present state of PC road bridges in Japan` classified PC road bridges ranging from an early PC beam bridge to a recent PC cable stayed bridge and PC extra-dosed bridge for every kind and period, and systematically presented the growth of the Japanese highway network and PC bridge. The inspector group visited 3 bridges in Singapore, and 3 bridges in Hong Kong. 8 figs., 2 tabs.

  2. Geopolymers prepared from DC plasma treated air pollution control (APC) residues glass: properties and characterisation of the binder phase.

    Science.gov (United States)

    Kourti, Ioanna; Devaraj, Amutha Rani; Bustos, Ana Guerrero; Deegan, David; Boccaccini, Aldo R; Cheeseman, Christopher R

    2011-11-30

    Air pollution control (APC) residues have been blended with glass-forming additives and treated using DC plasma technology to produce a high calcium aluminosilicate glass (APC glass). This has been used to form geopolymer-glass composites that exhibit high strength and density, low porosity, low water absorption, low leaching and high acid resistance. The composites have a microstructure consisting of un-reacted residual APC glass particles imbedded in a complex geopolymer and C-S-H gel binder phase, and behave as particle reinforced composites. The work demonstrates that materials prepared from DC plasma treated APC residues have potential to be used to form high quality pre-cast products. Copyright © 2011 Elsevier B.V. All rights reserved.

  3. Covalent Coupling of Organophosphorus Hydrolase Loaded Quantum Dots to Carbon Nanotube/Au Nanocomposite for Enhanced Detection of Methyl Parathion

    Energy Technology Data Exchange (ETDEWEB)

    Du, Dan; Chen, Wenjuan; Zhang, Weiying; Liu, Deli; Li, Haibing; Lin, Yuehe

    2010-02-15

    An amperometric biosensor for highly selective and sensitive determination of methyl parathion (MP) was developed based on dual signal amplification: (1) a large amount of introduced enzyme on the electrode surface and (2) synergistic effects of nanoparticles towards enzymatic catalysis. The fabrication process includes (1) electrochemical deposition of gold nanoparticles by a multi-potential step technique at multiwalled carbon nanotube (MWCNT) film pre-cast on a glassy carbon electrode and (2) immobilization of methyl parathion degrading enzyme (MPDE) onto a modified electrode through CdTe quantum dots (CdTe QDs) covalent attachment. The introduced MWCNT and gold nanoparticles significantly increased the surface area and exhibited synergistic effects towards enzymatic catalysis. CdTe QDs are further used as carriers to load a large amount of enzyme. As a result of these two important enhancement factors, the proposed biosensor exhibited extremely sensitive, perfectly selective, and rapid response to methyl parathion in the absence of a mediator.

  4. Numerical Investigation on the Thermo-mechanical Behavior of a Quadratic Cross Section Pile Heat Exchanger

    DEFF Research Database (Denmark)

    Pagola, Maria Alberdi; Madsen, Søren; Jensen, Rasmus Lund

    2017-01-01

    and, therefore, there is a need to develop guidelines to design them properly. This paper contributes by studying the thermo-mechanical behavior of the precast piles which are 15-meter long and have a quadratic cross section and a W-shape pipe heat exchanger. This article aims to numerically assess...... the additional changes in the pile load transfer generated by its heating and cooling. In addressing this objective, a preliminary multi-physical finite element analysis is conducted which serves as a tool for exploring: i) the thermally induced mechanical stresses within the concrete and on the pile-soil axial...... on the geotechnical capacity of a single energy pile. However, ground thermal loads need to be considered in the design phase to account for potential extreme temperature changes, which could generate thermal stresses that equalize the mechanically generated ones....

  5. Experimental and Numerical Investigation of the FRP Shear Mechanism for Concrete Sandwich Panels

    DEFF Research Database (Denmark)

    Hodicky, Kamil; Sopal, G.; Rizkalla, S.

    2015-01-01

    of this interface surface area. Test results also indicated that increasing the rigid foam thickness decreases the overall shear flow strength when compared with the same quantity of CFRP grid spacing. A nonlinear three-dimensional (3D) FEM analysis was performed to model the behavior of the tested segments......This paper investigates the composite action of 46 segments representing precast concrete sandwich panels (PCSPs) using a fiber-reinforced polymer [FRP; specifically, a carbon fiber-reinforced polymer (CFRP)] grid/rigid foam as a shear mechanism. The experimental aspect of the research reported...... reported in this paper indicated that increasing the spacing between vertical lines of CFRP grid increase the overall shear flow strengths due to the increase of the bonded contact area of the rigid foam to the concrete surface. However, the overall shear stresses were decreased due to the increase...

  6. Acoustical and thermal performance of multilayer closing panels used in steel-structured buildings

    Directory of Open Access Journals (Sweden)

    Rovadávia Aline de Jesus Ribas

    Full Text Available Abstract This article provides an evaluation of the acoustical and thermal performance of some closing systems by referencing materials such as cement plates, plasterboard walls, precast concrete panels and expanded polystyrene. Reverberation time is calculated by applying an empirical formula, which uses temperature and relative air humidity values obtained from simulations that were conducted using the computational simulation program ESP-r (Energy Simulation Program-research. The internal temperature presented by the ESP-r is an indicator of thermal performance. Using a simplified graphic method, the acoustical performance is also evaluated by estimating the loss of sound transmission that occurs through the closing panels. Combinations of these panels, which form multilayer panels mediated by a layer of air and with or without insulating material between them, are applied. The results show that multilayered closing systems, when filled with insulating material, are an efficient solution than can provide adequate acoustical and thermal performance.

  7. Acoustic Design of Super-light Structures

    DEFF Research Database (Denmark)

    Christensen, Jacob Ellehauge; Hertz, Kristian Dahl; Brunskog, Jonas

    in a controlled laboratory environment have been conducted with the element in order to evaluate its performance in airborne and impact sound insulation. These results have been employed in simulations of the flanking transmission to estimate the in-situ performance of the super-light slab element. The flanking...... transmission has been done both in a standard room consisting of precast concrete elements and as a parametric study in order to estimate the accuracy of the used model. Experiments on the ultimate limit state regarding moment, shear and pull-out resistance is carried out for the super-light element. As a part...... of the same test series elastic behaviour of the super-light element is also investigated. This is done to verify that requirements and methods supplied by design codes can be applied to the element with sufficient accuracy. In addition, the super-light slab element has been exposed to a standard fire test...

  8. Residual Mechanical Properties of Concrete Made with Crushed Clay Bricks and Roof Tiles Aggregate after Exposure to High Temperatures

    Directory of Open Access Journals (Sweden)

    Ivana Miličević

    2016-04-01

    Full Text Available This paper presents the residual mechanical properties of concrete made with crushed bricks and clay roof tile aggregates after exposure to high temperatures. One referent mixture and eight mixtures with different percentages of replacement of natural aggregate by crushed bricks and roof tiles are experimentally tested. The properties of the concrete were measured before and after exposure to 200, 400, 600 and 800 °C. In order to evaluate the basic residual mechanical properties of concrete with crushed bricks and roof tiles after exposure to high temperatures, ultrasonic pulse velocity is used as a non-destructive test method and the results are compared with those of a destructive method for validation. The mixture with the highest percentage of replacement of natural aggregate by crushed brick and roof tile aggregate has the best physical, mechanical, and thermal properties for application of such concrete in precast concrete elements exposed to high temperatures.

  9. HardCem : an innovative product and partnership

    Energy Technology Data Exchange (ETDEWEB)

    Joudrie, C. [Teck Cominco, Vancouver, BC (Canada)

    2007-07-01

    This paper described the multiple uses of Hard-Cem{sup TM}, a concrete hardener developed for ready-mix and pre-cast concrete applications. The product is engineered to improve the durability of concrete for air and non-air entrained construction projects including buildings, roads, bridges, dams and recreational facilities such as skate parks. The development history of Hard-Cem was reviewed along with its market introduction by Teck Cominco Limited. Technical and operating partnerships were also outlined along with future marketing opportunities. The concrete additive is engineered to increase abrasion resistance. It is added to the concrete during the batching and mixing operations where it is evenly dispersed through the concrete matrix with other proprietary ingredients. The recommended dosages were described along with performance data. The product was shown to save time and money while offering more resistance to mechanical and water borne abrasion forces in both interior and exterior concrete applications. tabs., figs.

  10. Aerial view of the CERN-Meyrin site during building work for the SPS

    CERN Multimedia

    1974-01-01

    Visible on the right hand site are three building areas: in front the area around pit 6 of the SPS (where the ejection to the West Area branches off), in the middle the area around the 'civil engineering pit 7', and in the back the area around the SPS pit 1 where injection takes place. The SPS tunnel, 6910 m in length with an inner diameter of 4m in its cross section, is at an elevation of 400 m above sea level corresponding to a depth below the surface which varies between 23 and 65 m. It has 6 regularly spaced access pits. The further pit 7 is situated on the injection line about 200m from the injection point. It was used to extract material excavated from the ring and to bring in the precast elements and the concrete for lining the tunnel with a shell of about 30 cm thickness.

  11. Effect of High-Temperature Curing Methods on the Compressive Strength Development of Concrete Containing High Volumes of Ground Granulated Blast-Furnace Slag

    Directory of Open Access Journals (Sweden)

    Wonsuk Jung

    2017-01-01

    Full Text Available This paper investigates the effect of the high-temperature curing methods on the compressive strength of concrete containing high volumes of ground granulated blast-furnace slag (GGBS. GGBS was used to replace Portland cement at a replacement ratio of 60% by binder mass. The high-temperature curing parameters used in this study were the delay period, temperature rise, peak temperature (PT, peak period, and temperature down. Test results demonstrate that the compressive strength of the samples with PTs of 65°C and 75°C was about 88% higher than that of the samples with a PT of 55°C after 1 day. According to this investigation, there might be optimum high-temperature curing conditions for preparing a concrete containing high volumes of GGBS, and incorporating GGBS into precast concrete mixes can be a very effective tool in increasing the applicability of this by-product.

  12. Mix design for improved strength and freeze-thaw durability of pervious concrete fill in Pearl-Chain Bridges

    DEFF Research Database (Denmark)

    Lund, Mia Schou Møller; Kevern, John T.; Schaefer, Vernon R.

    2017-01-01

    , fibers, and by internal curing using lightweight aggregate to best possibly meet the requirements for a fill material in Pearl-Chain Bridges. The 28-day compressive strength, splitting tensile strength, shear strength, permeability, and freeze-thaw durability were determined and compared for eight...... density, and thus the easiest to place. The addition of a high-range water reducing admixture and lightweight sand (expanded shale) for internal curing improved the 28-day compressive strength and splitting tensile strength. The coarse aggregate gradation had a large influence on permeability; however......Pearl-Chain Bridges are an innovative precast arch bridge technology which can utilize pervious concrete as fill material. The present study investigates how the mix design of the pervious concrete fill can be influenced by use of an air-entraining admixture, a high-range water reducing admixture...

  13. Mix design for improved strength and freeze-thaw durability of pervious concrete fill in Pearl-Chain Bridges

    DEFF Research Database (Denmark)

    Lund, Mia Schou Møller; Kevern, John T.; Schaefer, Vernon R.

    2017-01-01

    Pearl-Chain Bridges are an innovative precast arch bridge technology which can utilize pervious concrete as fill material. The present study investigates how the mix design of the pervious concrete fill can be influenced by use of an air-entraining admixture, a high-range water reducing admixture......, fibers, and by internal curing using lightweight aggregate to best possibly meet the requirements for a fill material in Pearl-Chain Bridges. The 28-day compressive strength, splitting tensile strength, shear strength, permeability, and freeze-thaw durability were determined and compared for eight...... different mixture proportions using two different sizes of granite coarse aggregate and at two different water-to-cement ratios. The specimens had an average void content of 24-28 %. Specimens containing air entraining and high-range water reducing admixtures were most workable, as determined by fresh...

  14. Petal of the cherry is expressed by large PCa, PC version; Ogata PCa {center{underscore}dot} PC ban de sakura no kaben wo hyogen. Toki orinpikku nagano taikai kai {center{underscore}dot} heikaishiki kaijo koji

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, Shigeo [Maeda Corp., Tokyo (Japan); Nemoto, Katsuyuki; Sueki, Tatsuya [Fudo Building Research Corp., Tokyo (Japan); Saito, Yuichi

    1998-07-10

    The opening and closing ceremony place construction. The south Nagano playfield park multipurpose stadium is the building, which becomes opening and closing ceremony place of the Olympic Winter Games Nagano convention. Large features of this stadium are appearance composed of enormous 'petal of the cherry'. Per 'petal of the cherry' 1 sheet constitutes 7 in precast prestressed concrete edition divided. The external wall of the petal of the cherry is called the PC petal. PCaPC member subject who receives the PC petal is called the PC calyx. Manufacturing and operation of PCaPC member subject adopted in the petal and the calyx made of the concrete are introduced. (NEDO)

  15. Project configured supply networks: Governance of delivery and failures in operations

    DEFF Research Database (Denmark)

    Koch, Christian

    2008-01-01

      Supply networks in complex B2B- construction deliver knowledge, materials, components, subsystems, competences, workforce and management. The delivery network and its governance forms are partly permanent, partly project specific. Integration upstream varies by project, constituting a range...... as theoretical frame. The case study is a Danish architectural, engineering and construction supply network for one building project. The governance forms found were; internal integration and hierarchy, SCM-efforts, subsystem deliveries, and contracting per project. There was a very uneven upstream integration......; Three engineering design areas were integrated with production and even the client. The architectural design is the most 'clear-cut' singular, whereas the supplies of pre-cast concrete core, elevator and kitchen were integrated knowledge, material, workforce and management subsystem deliveries. 160...

  16. Modified mortar pad behavior in the transfer of compressive stresses

    Directory of Open Access Journals (Sweden)

    J. D. Ditz

    Full Text Available ABSTRACT This research aims to analyze the compressive stress transfer between precast concrete elements using cement mortar pads modified with polypropylene fibers, styrene-butadiene latex and heat-expanded vermiculite. The stress transfer analyses are performed interleaving a cementbearing pad between two concrete blocks, subjecting the entire specimen to different compressive load tests. The parameters analyzed in the tests are: surface roughness (using bosses on the bonded phase of different thicknesses, compressive strength with monotonic and cyclic loadings. The main results obtained in this study are: a the presence of pad increased the strength in 24% for thicknesses of imperfections of 0.5 mm and approximately 12% for smooth faces blocks; b gain of effectiveness of the bearing pad when the concrete strength was reduced; c for cyclic loading, the bearing pad increased in 48% the connections strength.

  17. Puente del Guadalimar – España

    Directory of Open Access Journals (Sweden)

    Prieto, F.

    1973-10-01

    Full Text Available This bridge is a continuous precast concrete box, resting on three piers and their corresponding abutments. It has three 38 m spans each, and one main 54 m spark. The flooring edge is 3.5 m and the piles 17 m high. The bridge is designed for single track railway. This was a project of the Technical Office of Carlos Fernández Casado, S. A.El puente es un cajón continuo de hormigón pretensado, apoyado en tres pilas y sus correspondientes estribos. Tiene tres luces de 38 m cada una, y una luz central de 54 m. El canto del tablero es de 3,5 m y la altura de pilares de 17 m. El puente está diseñado para ferrocarril de vía única. Proyecto de la Oficina Técnica Carlos Fernández Casado, S. A.

  18. Material evidence in a digital context

    DEFF Research Database (Denmark)

    Egholm Pedersen, Ole

    2012-01-01

    In the pursuit of new physical and culturally responsive building elements, architects work primarily with digital parametric design tools used in conjunction with scale models. These models need to find their architectural potentials not only in geometric, aesthetic, and tactile qualities......, but also in the restrictions within an industrial production line. This article presents a method of experimentation with precast concrete, where prototyping using technologies suitable for industrial production provide the parameters for a parallel process of digital form-finding. The method takes its...... starting point in the term Tectonics, understood as a means of combining process and goal, in order to read the potentials of a technology and a material (Frampton, 2001). Informed by theories of technology (Heidegger, Kieran/Timberlake, 2003), practices that combines physical and digital means (Leach et...

  19. Sustainable Concrete Technology

    Directory of Open Access Journals (Sweden)

    Sim J.

    2015-12-01

    Full Text Available The growing concern over global warming and significant ecological changes requires sustainable development in all fields of science and technology. Concrete not only consumes huge amount of energy and natural sources, but also emits large amount of CO2, mainly due to the production of cement. It is evident that such large amount of concrete production has put significant impact on the energy, resource, environment, and ecology of the society. Hence, how to develop the concrete technology in a sustainable way has become a significant issue. In this paper, some of Korean researches for sustainable development of concrete are presented. These are sustainable strengthening for deteriorated concrete structure, sustainable reinforcement of new concrete structure, sustainable concrete using recycled aggregate and supplementary cementing materials and finally application of each technique to precast concrete.

  20. Experimental study of reinforced concrete pile caps with external, embedded and partially embedded socket with smooth interface

    Directory of Open Access Journals (Sweden)

    R. Barros

    Full Text Available On Precast concrete structures the column foundation connections can occur through the socket foundation, which can be embedded, partially embedded or external, with socket walls over the pile caps. This paper presents an experimental study about two pile caps reinforced concrete with external, partially embedded and embedded socket submitted to central load, using 1:2 scaled models. In the analyzed models, the smooth interface between the socket walls and column was considered. The results are compared to a reference model that presents monolithic connections between the column and pile cap. It is observed that the ultimate load of pile cap with external sockets has the same magnitude as the reference pile cap, but the ultimate load of models with partially embedded and embedded socket present less magnitude than the reference model.