摘要
为研究纤维编织网增强混凝土(Textile reinforced concrete,简称TRC)加固偏心受压水工结构的抗裂性能,对6根偏压短柱进行试验,研究了配网率和前期受力对TRC控制偏心受压结构裂缝的影响,在此基础上,建立了TRC加固下的偏心受压结构的裂缝扩展理论,进一步分析了裂缝的扩展规律。研究结果表明:对于一次受力结构,以基体材料开裂、受拉钢筋屈服为界限点裂缝呈现出3个扩展阶段;对于二次受力结构,滞后应变(前期受力历史造成)小于基体材料开裂应变时,裂缝扩展以加固点、基体材料开裂和受拉钢筋屈服为界限点呈现出4个扩展阶段,而当滞后应变大于基体材料开裂应变时,裂缝扩展以加固点、受拉钢筋屈服为界限点呈现出3个扩展阶段;在扩展阶段转变处,裂缝扩展速率(偏压荷载与裂缝扩展深度的比值)突增,但是在同一阶段内裂缝扩展速率逐渐减小;采用TRC可以有效地控制偏心受压结构主裂缝的发展,配网率越高,裂缝分布越均匀,条数越多,间距和扩展速率越小;前期受力对采用TRC抑制裂缝深度扩展的影响明显,而对抑制裂缝宽度扩展的影响较轻,总体而言前期受力历史越大,效果越差。
To study crack resistance of eccentric compression hydraulic structures with Textile reinforcedconcrete,the experiment of six eccentric compression columns under different textile ratios and pre-loadswas conducted.Based on the experiment result,the analytical theory of eccentric compression crack propaga-tion was proposed,and then the crack propagation law was investigated.The results show that for struc-tures under one-off load,the crack propagation phase is divided into three phases by cracking of matrixand yield of tensile steel.For structures under secondary load,when the post-strain（caused by preload）is smaller than cracking strain of matrix,the crack propagation is divided into four phases by applyingTRC layer,cracking of matrix and yield of tensile steel;when the post-strain is greater than crackingstrain of matrix,the crack propagation is divided into three phases by applying TRC layer and yield of ten-sile steel.In the transfer point of different phases,there is sudden increase for crack propagation rate（theratio between eccentric compression load and crack extend depth）.However,the crack propagation rate de-creases gradually at the same stage.The propagation of eccentric tension cracks can be controlled effective-ly by using TRC,the higher the textile ratio,the more even the distribution of cracks,the smaller thecracks gap and growth rate.The influence of preload on controlling crack propagation at depth is obviouswhile it is slight at width,overall,the larger the preload,the worse the controlling effect.
出处
《水利学报》
EI
CSCD
北大核心
2016年第1期101-109,共9页
Journal of Hydraulic Engineering
基金
国家重点基础研究发展规划(973)项目(2011CB013800)
国家自然科学基金项目(51508584)
