矿物掺合料对高性能混凝土断裂性能影响的试验研究

Experimental research on the influence of mineral admixture on fracture feature of high performance concrete

通过带缺口高性能混凝土小梁的三点弯曲断裂试验,研究了不同掺量的矿物掺合料粉煤灰、硅粉对高性能混凝土断裂性能的影响。根据试验得到的荷载-挠度曲线和荷载-裂缝嘴张开位移曲线,运用虚拟裂缝模型并结合线弹性断裂力学理论,计算了起裂韧度、失稳韧度、断裂能等断裂性能评价指标。试验表明:高性能混凝土断裂性能随活性矿物掺合料掺量的逐渐增大呈先增大后减小的趋势。

By means of three-point bending tests on small high performance concrete beams with notches,the influence on fracture behavior of high performance concrete with different volume of fly ash and silicon powder is studied.According to the load-deflection and load-crack opening displacement curves obtained through the experiments, evaluation index of fracture behavior such as initial fracture toughness,unstable fracture toughness and fracture energy are calculated combined with the theory of linear elastic fracture mechanics and the fictitious crack model.The test results indicate that the fracture behavior of high performance concrete first ascends and then descends with active mineral admixture increased.