钢纤维高强混凝土在不同应变率时的单轴受压性能

对不同钢纤维体积率 (Vf)的钢纤维高强混凝土 (SFRHSC)进行了不同应变率下单轴压缩试验 ,试验结果表明 :钢纤维的加入 ,不仅提高了混凝土的强度 ,还显著地提高了其韧性和阻裂能力 ,使其破坏形态从脆性改变到延性 ,并且在一定程度上缓解了试验机刚度不够高而对测试结果的负面影响 ,使试验结果更接近真实。随着应变率增大 ,SFRHSC强度提高 ,但韧性呈现下降趋势 ,且Vf 越大 ,韧性下降幅度越小。弹性模量和泊松比受Vf 和应变率的影响甚微。推荐了适合于SFRHSC应力 应变曲线的数学表达式。

Mechanical Properties of SFRHSC Under Uniaxial Compression with Different Strain Rate

Based on the experiments, the mechanical properties of SFRHSC with different fiber volume fractions ( V f) under uniaxial compression with different strain rates are studied. The results show that incorporating steel fiber into the matrix leads to further strengthening, remarkably toughening and crack arresting of the composites, and the failure patterns of matrix are changed from brittle to ductile, and the adverse effects caused by the insufficiency of the test machine stiffness are weakened, and the experiment results become more accurately. With the increase of the strain rate, the strength of SFRHSC increased but the toughness decreased, and the more the V f, the less decreasing of the toughness. With the change of the V f and the strain rate, the elastic modulus and Poisson's ratio of SFRHSC changed only a little. A well suited numerical expression of the compressive stress-strain curve to SFRHSC is put forward.