复合配筋预制混凝土管桩的抗弯抗剪性能试验研究

为进一步推广先张法预应力离心混凝土钢绞线桩(PSC桩)在高烈度抗震区的应用,在PSC桩中加入与钢绞线相同数量的螺纹钢筋,研发了先张法预应力离心混凝土复合配筋钢绞线桩(PSRC桩),并对3种规格共12根管桩试件进行了足尺抗弯及抗剪性能试验,对比分析了PSC桩和PSRC桩在抗裂性能、抗弯(剪)承载力、变形能力及裂缝分布等方面的异同。试验结果表明:非预应力钢筋的配置对管桩抗裂性能影响不大,但可以提高管桩的抗弯和抗剪性能;PSRC桩的开裂弯矩和开裂剪力与PSC桩相近,但极限弯矩和极限剪力则分别提高了约55%和20%;与PSC桩相比,PSRC桩破坏时桩身裂缝数量较多,分布范围较广,但最大裂缝宽度较小。

Experimental Study on Flexural and Shear Performance of Precast Concrete Piles with Composite Reinforcement

In order to further popularize the application of PSC piles in high intensity seismic areas,the same number of deformed steel bars as steel strands were added to PSC piles,and pretensioned centrifugal spun concrete piles with hybrid steel strands and reinforcing bars(PSRC piles)were developed.Through the bending and shear tests on twelve full-scale pile test specimens with three kinds of specifications,the differences of crack resistance,bending and shear bearing capacity,deformation capacity and crack distribution between PSC and PSRC piles were studied.The experiment results show that the arrangement of non-prestressing tendons has little effect on the crack resistance of piles,but can enhance the bending and shear bearing capacity.The cracking moment and shear force of PSRC piles are close to those of PSC piles,but the ultimate bending moment and shear force are about 55%and 20%higher,respectively.The non-prestressing tendons can also limit the crack development in pile body,the number of cracks for PSRC piles at failure is larger,the crack distribution is wider,but the maximum crack width is smaller.