钢纤维混凝土轴压应力-应变曲线试验研究

Experimental study on axial compressive stress-strain curve of SFRC

作为钢纤维混凝土配合比直接设计方法的研究工作的重要内容,采用4个平行于棱柱体试件对称放置的弹簧作为刚性辅助架,在普通压力试验机上成功地测得了纤维体积率0~2.0%、裹浆厚度0.8~1.2 mm、强度等级为CF40的钢纤维混凝土轴压应力-应变全曲线。根据试验结果,分析了纤维体积率和纤维裹浆厚度对钢纤维混凝土轴压强度、应力-应变曲线以及轴压韧性比的影响。表明钢纤维混凝土的轴压强度和韧性比随着纤维体积率的增加而提高,存在合理的纤维裹浆厚度使得钢纤维混凝土获得优良的轴压韧性。提出了与试验结果符合良好的钢纤维混凝土轴压应力-应变曲线计算理论模型。

As the important content of the research on direct design method for mix proportion of steel fiber reinforced concrete （ SFRC ）, the full axial compressive stress-strain curve of SFRC was successfully measured by ordinary testing machine assisted by the 4 rigid springs symmetrical placed parallel to the prism specimen.The fraction of fiber by volume was from zero to 2.0%, the thickness of paste wrapping fiber was from 0.8 mm to 1.2 mm and the strength grade of SFRC was CF40.Based on the test result,the effects of the fraction of fiber by volume and the thickness of paste wrapping fiber on the axial compressive strength, the stress-strain curve and the axial compressive toughness ratio of SFRC were analyzed.It was shown that the axial compressive strength and toughness ratio of SFRC increase with the increase of the fraction of fiber by volume,there was a reasonable value of the thickness of paste wrapping fiber to make the better compressive toughness ratio of SFRC.The theoretical model for calculating the axial compressive stress-strain curve of SFRC is proposed, which fit better with the test results.