摘要
采用高强、超高强混凝土并通过增脆、增韧措施获得不同脆性的混凝土，根据对不同混凝土劈拉强度尺寸效应的试验研究，分析材料脆性对混凝土强度尺寸效应影响。结果表明：脆性越大的混凝土劈拉强度越快接近极限抗拉强度，尺寸效应表现出更快稳定的趋势；引气和掺加钢纤维，改变混凝土材料脆性，但不影响劈拉强度尺寸效应的规律；由于尺寸效应影响，普通钢纤维对混凝土增韧增强作用在超高强混凝土中将显著减弱；以分形理论为依据的Carpinteri的强度尺寸效应律，在结构非稳定开裂的条件下较真实。
For investigating the influence of brittleness on the size effect of concrete strength, the splitting tensile strength of high or super-high strength concretes, with different brittleness levels, are tested. The results show that： the higher is the brittleness of concrete, the sooner the splitting tensile strength reaches the ultimate tensile strength, meanwhile, the size effects tends to be stable immediately; the brittleness of concrete can be altered by entraining air or adding steel fiber, but the law of size effect of strength is unchangeable. For super-high strength concrete, the effects of toughening and reinforcing by applying the normal steel fiber are significantly weakened as the impact of size effects. The size effect law suggested by Carpinteri, which was based on the fractal theory, is proved more reasonable under the condition of unstable cracks of a concrete structure.
出处
《工程力学》
EI
CSCD
北大核心
2012年第4期192-196,共5页
Engineering Mechanics
基金
国家自然科学基金项目（59778053）
重庆市科委攻关项目（CSTC,2009AC7058）
关键词
混凝土
脆性
劈拉强度
强度尺寸效应
钢纤维
concrete
brittleness
splitting tensile strength
size effect of strength
steel fiber
