配筋对混凝土双K断裂参数的影响研究  

Influence of steel bars on double-K fracture parameters of concrete

作　　者：胡少伟[1] 米正祥[1] 陆俊[1] 

机构地区：[1]南京水利科学研究院材料结构研究所,江苏南京210029

出　　处：《人民长江》2012年第13期61-65,共5页Yangtze River

基　　金：国家科技支撑计划课题"震损水库及堰塞湖风险评估与处置关键技术研究"(2009BAK56B04);国家自然科学基金项目"基于FEMOL的大口径PCCP管结构计算与安全评价"(50879048);水利部前期项目"地震对大坝灾变机理与对策研究"(S409001)

摘　　要：为了确定在混凝土中配筋对试件断裂参数的影响,采用尺寸为1 000 mm×200 mm×200 mm的3组不同缝高比的钢筋混凝土试件进行试验。通过在初始裂缝两侧粘贴应变片确定了起裂荷载,计算出了钢筋混凝土试件的起裂断裂韧度、失稳断裂韧度、临界有效裂缝长度,并与相同缝高比的素混凝土试件进行了对比。结果表明,在混凝土中配筋,其起裂断裂韧度与失稳断裂韧度分别可以提高8.6%与15%;缝高比越大,钢筋混凝土试件的起裂韧度与失稳韧度值越小;钢筋混凝土试件的起裂韧度与失稳韧度的比值要比素混凝土试件的小,表明在混凝土试件中加入钢筋后可以提高结构的延性;钢筋混凝土试件的初始缝长与临界有效缝长的比值介于0.65～0.88。We conducted an experiment to determine the influence of steel bars on fracture parameters of concrete samples with three groups of different crack - depth ratios of reinforced concrete specimens of the size of 1000mm × 200mm × 200mm. The initial cracking load was determined by pasting strain gauge on two sides of cracks. We calculated the initial toughness, unstable toughness and the critical effective crack length of the reinforced concrete, all the above results were corapared with those with the same crack - depth ratios of normal concrete. The results show that due to steel bars, the initial fracture toughness and unstable fracture toughness can be increased by 8.6% , 15% respectively. Initial toughness and unstable toughness decrease with increasing of crack - depth ratio. The rate of initial toughness to unstable toughness of reinforced concrete is smaller than the normal concreteS, which reveals that the reinforcement can increase the ductility of structure. The ratio of initial length to critical effective length of reinforced concrete is 0. 65 - 0. 88.

关 键 词：钢筋混凝土 双K断裂参数 缝高比 钢筋影响 

分 类 号：TV33[水利工程—水工结构工程]