Loading Behaviors of Superposed Aqueduct Affected by Segregating Layer Between PPCBs and Cast-In Situ RCF

2010 ◽  
Vol 37-38 ◽  
pp. 614-618
Author(s):  
Shun Bo Zhao ◽  
Song Wei Pei ◽  
Yang Wei Wang ◽  
Xi Jian Liang
Keyword(s):  
Prestressed Concrete ◽  
Structural Design ◽  
Concrete Beams ◽  
Internal Surface ◽  
Finite Element Models ◽  
Tensile Stresses ◽  
North Water ◽  
The Many ◽  
Precast Prestressed Concrete

Combined with the structural design of left-shore drainage aqueducts in China South-to-north Water Transfer Project, the structure of cast-in-situ reinforced concrete flume (RCF) with wide and shallow drainage section superposed on longitudinal precast prestressed concrete beams (PPCBs) was drafted. The 3D finite element models were built to study the normal service behaviors of the aqueduct with or without segregating asphalt layer between RCF and PPCBs. The results show that the segregating asphalt layer changes the structural compositions of aqueduct subjecting water loads and results in some effects on loading capacities of the PPCBs and the RCF, such as the larger displacement and tensile stress of PPCBs, the many longitudinal sections of subplate in whole tensile state with larger tensile stresses and the larger vertical tensile stresses at internal surface of sidewall. It provides valuable reference for designing the same kind of aqueduct.

Construction planning of single-span bridges using precast, prestressed concrete beams

1982 ◽  
Vol 9 (3) ◽  
pp. 422-430
Author(s):  
Sami M. Fbreig
Keyword(s):  
Prestressed Concrete ◽  
Concrete Beams ◽  
Critical Path ◽  
Time Cost ◽  
Southern Ontario ◽  
Daily Work ◽  
Project Completion ◽  
Project Network ◽  
Precast Prestressed Concrete

In this paper representational data are given that can be used for the planning of single-span prestressed bridge construction. The project-network is represented, together with the critical path and time–cost relation, which has been calculated. Schedules for manpower and equipment required for project completion are also shown, as well as the owner's cash flow. The application of such data to construction of similar projects in different locations and/or in the future is discussed. The bridges under consideration were constructed using precast, prestressed concrete beams and the deck was cast in situ to act compositely with the beams. To establish these data, the daily work reports and progress payment certificates of five bridges, built in southern Ontario between 1976 and 1980, have been analyzed. Average values, based on the data of the five bridges, were utilized in this analysis.

scholarly journals Analysis of Prestressing in Precast Prestressed Concrete Beams

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jakub Kraľovanec ◽  
Martin Moravčík ◽  
Jozef Jošt
Keyword(s):  
Numerical Analysis ◽  
Service Life ◽  
Prestressed Concrete ◽  
Concrete Beams ◽  
Direct Methods ◽  
Actual State ◽  
Indirect Methods ◽  
Remaining Service Life ◽  
Prestressing Force ◽  
Precast Prestressed Concrete

Abstract Knowledge of prestressing force’s value is in the case of prestressed concrete structure the most important basis for defining load-carrying capacity and remaining service life. Numbers of prestressed concrete structures are about to reach their limit of service life and they are exhibiting signs of deterioration due to the conceptional errors, inadequate maintenance and environmental distress. All of these factors negatively influence the actual state of prestressing. Thus, it is essential to determine the value of prestressing force considering the degradation of materials, such as corrosion of prestressing strands or wires. While assessing structure in service, it is difficult to apply magnetoelastic sensors or use other direct methods for determining the state of prestressing. Hence, the indirect methods enable to analytically calculate the prestressing force based on the results of measurement, e.g. strain, stress, deflection, or width of the crack. The present paper focuses on numerical analysis of prestressing in a twosome of precast prestressed concrete beams. For the numerical analysis, two indirect methods are applied, specifically Saw-cut method and Crack initiation method. Finally, the results are discussed and recommendations for the experimental campaign are summarized.

scholarly journals Behaviour of cast in situ reinforced concrete frames incorporating precast prestressed concrete beam shells subjected to seismic loading

1984 ◽  
Vol 17 (4) ◽  
pp. 223-250
Author(s):  
R. Park ◽  
D. K. Bull
Keyword(s):  
Reinforced Concrete ◽  
Prestressed Concrete ◽  
Concrete Beam ◽  
Plastic Hinge ◽  
Seismic Loading ◽  
Hinge Region ◽  
Design Code ◽  
Concrete Frames ◽  
Precast Prestressed Concrete

The performance of cast in situ reinforced concrete frames incorporating precast prestressed concrete U-beam shells, subjected to seismic loading, is investigated. The precast U-beams act as permanent formwork and are not connected by steel to the cast in situ concrete of the beam or column. A review of the design provisions of the New Zealand concrete design code NZS 3101 relevant to the design of such composite structures is made and supplementary design recommendations are proposed where necessary. Three full scale reinforced concrete beam-exterior column subassemblies with precast prestressed concrete U-beam shells were constructed and tested to determine their seismic performance characteristics. Two of the subassemblies were designed for
seismic loading with potential plastic hinge regions in the beams. One of these subassemblies had the bond between the precast and
the cast in situ concrete in the beam deliberately broken in the potential plastic hinge region, while the other was bonded. The third subassembly was not designed for seismic loading. The test results for the two subassemblies designed for seismic loading demonstrated that the seismic provisions of the New Zealand concrete design code, in conjunction with the supplementary design recommendations, resulted in adequately ductile behaviour with satisfactory energy dissipating characteristics. It was observed that the U-beam was less damaged during seismic loading when the bond between the precast and the cast in situ concrete in the potential plastic hinge region was deliberately broken. The performance of the other composite beam-column subassembly, which was not designed for seismic loading, was unsatisfactory, since the energy dissipating characteristics were poor and excessive sliding shear displacements occurred in the plastic hinge region.

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