混杂纤维增强高性能混凝土断裂能研究

通过纤维总体积掺量不超过1%的钢纤维、钢-聚丙烯、钢-塑钢混杂纤维混凝土带切口梁三点弯曲试验,测试出了混杂纤维增强混凝土的荷载-挠度曲线和荷载-裂缝口张开位移(CMOD)曲线,计算出对应的断裂能与等效抗弯强度并进行对比分析.结果表明:纤维体积掺量为1.0%混杂纤维增强高性能混凝土的荷载-挠度曲线和荷载-CMOD曲线形状和走势相似且包围面积大于素混凝土,具有良好的韧性性能;混杂纤维的掺入能大幅提高混凝土的断裂能,最大提高了6.98倍,其中钢纤维起主要作用;综合利用断裂能和等效抗弯拉强度feq1、feq2可以全面描述混杂纤维混凝土梁在受弯过程中的破坏特征与韧性变化.

Experimental study on fracture energy of hybrid fiber reinforced high performance concrete

Experimental tests on three-point bending fracture of hbrid fiber reinforced concrete with the total volume of steel fibers,steel-polypropylene fiber,steel-polypropylene fiber does not more than 1%,and acquire the characteristics of the load-deflection curves,the load-CMOD curves,calculate the corresponding fracture energy and compare it with the equivalent bending strength.The test results indicate that the load-deflection curves and the load-CMOD of hybrid fiber reinforced high performance concrete are similar in shape and trend,the surrounding area is larger than plain concrete with good toughness.Hybrid fiber can greatly improve the fracture energy of concrete,up to 6.98 times,steel fiber plays a major role in the impact of concrete fracture energy.Using fracture energy and equivalent bending strength feq1,feq2 synthetically can fully describe the failure characteristics and toughness changes of the specimen during bending.