混杂纤维协同增强轻骨料混凝土力学性能试验研究

Hybrid fiber synergistic reinforcement of the mechanical properties of lightweight aggregate concrete

应用正交试验法设计16组钢-聚丙烯纤维轻骨料混凝土(HF-LAC)来进行抗压及劈裂抗拉强度试验。结果表明:钢-聚丙烯混杂纤维掺入轻骨料混凝土中能显著提高其抗压强度和劈裂抗拉强度;四种因素对HF-LAC劈裂抗拉强度的增强效应大于抗压强度,钢纤维、聚丙烯纤维、陶粒和陶砂对HF-LAC劈裂抗拉强度最大增幅分别为11.61%、3.23%、5.05%和0.91%;聚丙烯纤维是影响HF-LAC抗压强度特别显著因素,钢纤维是影响HF-LAC劈裂抗拉强度特别显著因素;基于功效系数法得出当钢纤维体积率为0.3%,聚丙烯纤维体积率为0.2%,陶粒代石子率为7%,陶砂代砂子率为15%时HF-LAC力学性能最佳。基于SEM微观扫描对纤维与基体的粘结机理进行分析,并建立四因素对HF-LAC强度预测模型。

Sixteen groups of steel-polypropylene hybrid fiber lightweight aggregate concrete(HF-LAC)were designed by orthogonal test method to carry out compressive and splitting tensile strength tests.The results show that the steel-polypropylene hybrid fiber mixed into lightweight aggregate concrete can significantly increase its compressive strength and split tensile strength;the four factors have greater effect on the HF-LAC split tensile strength than the compressive strength.Steel fiber,polypropylene fiber,ceramsite and ceramic sand have the largest increase in HF-LAC splitting tensile strength by 11.61%,3.23%,5.05%and 0.91%respectively;polypropylene fiber has a particularly significant impact on the compressive strength of HF-LAC Factors,steel fiber is a particularly significant factor affecting the HF-LAC splitting tensile strength;based on the efficiency coefficient method,the volume rate of steel fiber is 0.3%,the volume rate of polypropylene fiber is 0.2%,and the rate of ceramsite replacement stone is 7%,HF-LAC has the best mechanical properties when the replacement ratio of terracotta sand is 15%.Based on SEM,the bond between fiber and matrix was analyzed,and the prediction model of four factors on the strength of HF-LAC was established.