棉花秸秆纤维混凝土力学性能试验研究

Study on Mechanical Performance Test of Concrete with Cotton Straw Fibers

为研究棉花秸秆纤维掺量对混凝土力学性能的影响,分别对不同掺量的棉花秸秆纤维混凝土进行了抗压、劈裂抗拉和抗折试验;并通过SEM电镜扫描,对棉花秸秆纤维混凝土的微观结构做了分析。试验结果表明:随着棉花秸秆纤维掺量的增加,混凝土抗压、劈裂抗拉、抗折强度和拉压比、折压比均呈现先增加、后减小的趋势,最大增幅分别达到17.95%、24.89%、32.71%、5.89%和12.5%。SEM分析表明,适量的棉花秸秆纤维在混凝土内部具有较好的分散性,与混凝土基体桥接性较好;棉花秸秆纤维掺量过高,会出现纤维结团现象,降低棉花秸秆纤维与混凝土基体的黏结性能。当棉花秸秆纤维掺量为2.0 kg/m 3时,混凝土力学性能最佳。

In order to study the additive amount of the cotton straw fiber affected to the concrete mechanical performances,a compressive strength test,split tensile strength test and bending strength test were individually conducted on the concretes with different additive cotton straw fibers.With the scanning electron microscopy(SEM),an analysis was conducted on the microstructure of the concretes with the cotton straw fibers.The test results showed that with the increased additive amount of the cotton straw fibers,the compressive strength,split tensile strength,bending strength,tensile compression ratio and bending compression ratio of the concrete would firstly increased and than would be decreased in tendency.The max increased rate would be individually reached by 17.95%,24.89%,32.71%,5.89%and 12.5%.The SEM analysis showed that the proper cotton straw fibers mixed in the concrete could have a good dispersibility and would have a good connectedness with the concrete matrix bridge.The over additive amount of the cotton straw fibers would have the fiber agglomeration phenomenon and would reduce the bond performance between the cotton straw fiber and the concrete matrix.When the additive amount of the cotton straw fibers was 2.0 kg/m 3,the concrete mechanical performance would be optimum.