低周反复荷载作用下无粘结部分预应力混凝土梁受弯性能的试验研究

本文对不同配筋率的14根无粘结部分预应力混凝土梁进行了低周反复荷载试验。试验结果表明:实测试验梁的无粘结预应力筋极限应力比按无粘结预应力混凝土结构技术规程犤1犦的公式计算值低2.8%;正向极限荷载下破坏截面受压区相对高度ξp与综合配筋指标β0线性相关,与文献犤2犦单调加载时的回归分析结果接近;正向极限弯矩Mu试验值比按平截面假定求得的极限弯矩计算值略低,与文献犤2犦单调加载时比较承载力低11.3%左右。而综合配筋指标β0≤0.3的无粘结部分预应力混凝土梁具有较好的滞回延性。

Experimental study of unbonded partial prestressed concretebeams under low cyclic loadings

In this paper, fourteen unbonded partial prestressed concrete rectangular beams with different longitudinal reinforcement ratios were tested under low cyclic loadings. The experimental results indicated that the measured ultimate stress values in unbonded prestressed tendons are 2.8%lower than those calculated by the formulae of Chinese Technical Specification for Concrete Structures Prestressed with Unbonded Tendons. The relative depth of the compression zone ξp and the composite reinforcement index β0 are close to the results of regression analysis of reference, in which the beams are subjected to monotonic loading. And the experimental values of positive ultimate moment Mu are a little lower than the calculated values based on Bernoulli s principle and they are about 11.3%lower than the results of reference, while the unbonded partial prestressed concrete beams with composite reinforcement index β0≤0.3, the beams have better hysteresis ductility.