钢纤维混凝土力学性能和弯曲韧性研究

摘要

Four groups ( 15 beams of each ) of steel fiber reinforced concrete incision beam test are carried out with respective content of 25、30、35 and 40 kg/m3 to study the mechanical properties, flexural toughness and optimal content of steel fiber reinforced concrete. Through the analysis of load-deflection curves, it is found that steel fiber can greatly improve the mechanical properties and flexural toughness of concrete after cracking, and the second peak load of cracking is increased by 41. 5% compared with that of the initiative crack load. Then the curve relationship between the energy absorption of unit mass steel fiber and the steel fiber content is obtained though studies on energy absorption and flexural toughness ratio of steel fiber reinforced concrete based on CECS 13 : 2009 standard. Meanwhile, the relationship formula between flexural toughness ratio and steel fiber content is deduced. The results indicate that the optimal steel fiber content which could maximize the flexural toughness is 36 kg/m3 .%为研究钢纤维混凝土的力学性能、弯曲韧性及最优钢纤维掺量,进行掺量为25、30、35、40 kg/m3的4组(每组15根)钢纤维混凝土切口梁试验.通过对荷载-挠度变化规律曲线分析,发现钢纤维掺入对混凝土开裂后的力学性能、弯曲韧性有显著提高,开裂后荷载二次峰值较初裂荷载最大提高了41.5%;基于CECS 13:2009标准,分析钢纤维混凝土的能量吸收和弯曲韧性比,获得单位质量钢纤维能量吸收与钢纤维掺量的曲线关系,并推导弯曲韧性比与钢纤维掺量间的关系式,结果认为掺量为36 kg/m3时钢纤维能够最大程度发挥其弯曲韧性作用.