PE-ECC断裂性能试验研究

Experimental research on fracture performance of PE-ECC

为了研究纤维掺量对超高韧性水泥基复合材料(ECC)断裂性能的影响以及沙漠砂用于制备ECC的可行性,本文利用新疆本地原材料以及聚乙烯纤维(PE)制作了PE-ECC单边切口梁,通过三点弯曲试验与电测法测得了ECC的起裂韧度,通过分析荷载-裂缝开口位移曲线计算出失稳韧度,通过分析荷载-裂缝开口位移曲线计算出断裂能。研究表明:1)当沙漠砂取代率为40%时,PE-ECC具有应变硬化性能与多缝开裂特征;2)PE-ECC的失稳韧度约为起裂韧度的4倍左右,断裂能的变化范围为6.13×10^(3)~9.16×10^(3) N/m;3)当沙漠砂取代率为40%时,纤维掺量为1.5%PE-ECC的断裂性能表现最优,采用沙漠砂替代部分天然砂进行ECC的制备ECC是可行的。

In order to study the influence of fiber content on the fracture performance of ultra-high toughness cement-based composites(ECC)and study the feasibility of using desert sand to prepare ECC,a PE-ECC unilateral notched beam is made by using Xinjiang local raw materials and polyethylene fiber,the crack initiation toughness of ECC is measured by three-point bending test and electrical measurement,the unstability toughness is calculated by analyzing the load-crack opening displacement curve,and the fracture energy is calculated by analyzing the load-crack opening displacement curve.The results show that:1)When the replacement rate of desert sand is 40%,PE-ECC has the characteristics of strain hardening and multi-crack cracking;2)The unstability toughness of PE-ECC is about 4 times of the crack initiation toughness,and the range of fracture energy is 6.13×10^(3)~9.16×10^(3) N/m;3)When the replacement rate of desert sand is 40%,the fracture performance of PE-ECC with fiber content of 1.5%is the best,and it is feasible to use desert sand instead of natural sand to prepare ECC.