钢筋-钢纤维混凝土牛腿抗裂性能的试验研究  

On Crack Behavior of Steel-Fibre Reinforced Concrete Brackets

作　　者：王春印[1] 杨光华[1] 

机构地区：[1]西北工业大学

出　　处：《西北工业大学学报》1992年第4期467-473,共7页Journal of Northwestern Polytechnical University

摘　　要：本文对10个牛腿试件进行了抗裂性能试验。试验结果表明:将钢纤维掺入牛腿中,牛腿的开裂荷载提高了29％到49％。以牛腿出现垂直裂缝为依据,采用分层法,在复合材料宏观力学理论的基础上,提出了钢筋-钢纤维混凝土牛腿的开裂荷载计算公式。试验值和理论计算值吻合较好。Chinese building code still lacks specific requirements concerning crack behavior of steel fibre reinforced concrete bracket. This paper furnishes some information on crack load of steel fibre reinforced concrete bracket. Such information is believed to be of some use when specific requirements on steel-fibre reinforced concrete in Chinese building code are considered. This paper presents test results on crack load of steel-fibre reinforced concrete bracket and a formula for computing such load. Our test results show that crack strength of steel-fibre reinforced concrete bracket is 1.25-2.125 times that of normal concrete bracket. Crack strength in the bracket is the load at which a crack parallel to column axis (the left crack in fig.1) appears. Crack strength Q_(fu) may be computed by eq. (11) in the full paper. In the derivation of . (11), the position of the neutral axis of the cross-section containing the crack just before the crack occurs has to be determined. The position of such a neutral axis is determined by . (3), in which a coefficient a appcas. α is so adjusted as to make computed value of neutral axis position agree with that determined by electric strain gauge measurements. Computed Q_(fu) values agree quite well with experimental results. Ten bracket specimens were tested. The size of the steel fibre is 0.35×0.6×25mm and the steel fibre volume ratios are 0, 0.5%, 1.0%, and 2.0%.

关 键 词：钢筋-钢纤维 混凝土 牛腿 开裂 载荷 

分 类 号：TU377[建筑科学—结构工程]