混杂纤维高强混凝土断裂性能  

Fracture properties of hybrid fiber reinforced high-strength concrete

作　　者：高丹盈[1] 王占桥[1] 朱海堂[1] 王宝庭[1] 

机构地区：[1]郑州大学河南省工程材料与水工结构重点实验室,郑州450002

出　　处：《水力发电学报》2008年第1期129-134,共6页Journal of Hydroelectric Engineering

基　　金：国家自然科学基金(59479001)

摘　　要：本文通过30个尺寸为200mm×170mm×100mm的混杂纤维高强混凝土试件的楔劈拉伸试验,探讨钢纤维与聚丙烯纤维混杂效应及其对高强混凝土断裂韧度、断裂能和临界裂缝张开位移的影响。试验结果表明:加入纤维改善了高强混凝土的断裂性能。随着钢纤维体积分数(fρ)的增加,断裂参数增益比呈线性增加。聚丙烯纤维在小开裂位移条件下,对高强混凝土的开裂有约束作用,该效应随着位移的增加逐渐消失,钢纤维在混杂纤维高强混凝土断裂性能的改善方面起着主导作用。fρ=1.5%、聚丙烯纤维掺量Vf=0.6kg/m3为本次试验配合比条件下的最佳纤维掺量组合。本文在试验的基础上,建立了混杂纤维高强混凝土断裂韧度、断裂能和临界裂缝嘴张开位移的计算公式。Though wedge-splitting tensile test on the thirty specimens of hybrid fiber reinforced high-strength concrete （HFHSC） with the size of 200mm×170mm × 100mm, this paper explores the hybrid effect and the impact of steel fiber volume fraction and polypropylene fiber dosage on the fracture properties, such as fracture toughness （ KIc ）, fracture energy （ GF ） and critical crack mouth opening displacement （ δc ） of high-strength concrete. The test results indicate that the addition of fiber is helpful to improve the fracture properties of high strength concrete. The increment ratio of fracture parameters of HFHSC, such as fracture toughness （ KhIc ）, fracture energy （ GhF ） and critical crack mouth opening displacement （ δhc ）, increases linearly with increase of steel fiber volume fraction. Polypropylene fiber can restrain the cracking of high strength-concrete, but this effect disappears as the displacement increases, Steel fiber is more beneficial to increase the fracture properties of high strength concrete than polypropylene fiber in HFHSC. The best fiber compounding can be gotten when steel fiber volume fraction is 1.5 % and polypropylene fiber dosage is 0.6kg/m^3. Based on the experimental data, the formulas for calculating the fracture toughness, fracture energy and critical crack mouth opening displacement of HFHSC are proposed.

关 键 词：建筑材料 断裂性能 断裂韧度 高强混凝土 断裂能 裂缝嘴张开位移 混杂纤维 

分 类 号：TV4[水利工程—水工结构工程]