Investigating the use of high performance concrete in partially prestressed beams and optimization of partially prestressed ratio

Yousef Zandi

doi:10.17485/ijst/2012/v5i7.2

Abstract

The main objective of this study is to investigate the behaviour of partially prestressed concrete (PPC) beams subjected to pure flexure. The test beams were produced using both high performance concrete (HPC) and traditional concrete (TC). Test beams were compared with each other for strength, strain and cracking cases. The comparison was done by theoretical and experimental methods. Test measurements included failure loads, deflections, strains in concrete and steels, failure moments and service moments, experimental safety coefficients, number of cracks, crack widths, curvatures. Thus, optimum partially prestress ratio was determined for HPC and TC. Advantages of using HPC in partially prestressed beams were brought out. According to the results of the study, optimum partially prestress ratio for PPC beams produced using traditional concrete is ~ 60%; while it is ~ 70% when HPC is used. The test results are shown that the usage of HPC in PPC beams is more convenient than the TC under some boundaries and conditions.

Highlights

Construction techniques were revealed as reinforced concrete, prestressed concrete and partially prestressed concrete
Prestressed force on active reinforcement (P=55kN) was of high performance concrete and traditional concrete are transferred to beams 14 days later from concrete dump
It is understood here that optimum partially prestressed ratio of partially prestressed concrete beams produced by using high performance concrete is approximately 70% in terms limitation of strain

Summary

Introduction

Construction techniques were revealed as reinforced concrete, prestressed concrete and partially prestressed concrete. Passive reinforcements of partially and fully prestressed concrete test beams were put into cross-section with corrosion space. 4) PPTab; Partially Prestressed Beam with Traditional Concrete a: Active (Mp) to total carrying moment ın the case of to be both active and passive reinforcing steel in beam section (Mp+Ms) is defined as partially prestressed ratio (PPR=Mp/Mp+Ms). Prestressed force on active reinforcement (P=55kN) was of high performance concrete and traditional concrete are transferred to beams 14 days later from concrete dump. As seen from this figure, rigidities under service loads of beams increase rapidly until 70% values of partially prestressed ratio. It is understood here that optimum partially prestressed ratio of partially prestressed concrete beams produced by using high performance concrete is approximately 70% in terms limitation of strain

Conclusion

F: Fully Prestressed Concrete Analysis of cracking state of beams

Findings

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