影响混凝土断裂性能若干因素的试验研究

采用RILEM推荐的双参数：临界应力强度因子(KIC^S)和临界裂缝尖端张开位移(CTODC)，同时还采用了特征长度lch研究了不同粗骨料粒径、不同硅灰掺量以及不同养护条件下这3个因素对混凝土断裂特性的影响。试验结果表明，粗骨料粒径增大，高强混凝土的抗压强度、弹性模量、劈拉强度和临界应力强度因子增大，脆性减小；标准养护时间越长，高强混凝土的抗压强度、弹性模量、劈拉强度以及临界应力强度因子的值越大，混凝土的脆性越小；掺加硅灰提高了混凝土的抗压强度、弹性模量、劈拉强度和临界应力强度因子，但却增大了混凝土的脆性。

Experimental Study on Some Factors Affecting Fracture Property of Concrete

Two parameters proposed by RILEM,the critical stress intensity factor K ICS and critical crack tip opening displacement CTOD C ,and third parameter of the characteristic length l ch are applied for investigation of fracture characteristics of concrete,which is with different size of coarse aggregate and different content of silica fume,and under different curring condition.All specimens were tested at28days.The test results showthat for high strength concrete the compressive strength,splitting tensile strength,elastic modulus and critical stress intensity factor increase with the coarse aggregate size decreases,while the concrete behaves less brittleness.The use of silica fume improves the compressive strength,splitting tensile strength,elastic modulus and critical stress intensity factor of concrete;but at the same time,the concrete added with silica fume becomes more brittle.The longer the time of moist curing,the higher the values of compressive strength,splitting tensile strength,elastic modulus and critical stress intensity factor are.