摘要
为了解混凝土的尺寸效应,进行了混凝土动态抗压性能试验,分析了在不同试件尺寸(150,300,450 mm立方体)不同应变速率(10-5/s,10-4/s,10-3/s,10-2/s)下混凝土的应力-应变全曲线、吸能特性,并基于Bazant尺寸效应理论建立了含应变速率效应的混凝土强度的尺寸效应模型。结果表明,混凝土力学性能存在明显的尺寸效应和速率效应;混凝土单位体积的吸能能力随试件尺寸的增大而降低;在应变速率较小时,混凝土的吸能能力随应变速率的增大而增加;但应变速率超过一定值后,混凝土吸能能力增加不明显;混凝土应变软化程度随试件尺寸的增大而加深;在一定程度上,峰后应变软化程度取决于试件几何尺寸。
Dynamic compressive test of concrete performance was conducted on specimens with different sizes (1 50, 300,450mm cubes)under different strain rates (1 0 -5 /s,1 0 -4 /s,1 0 -3 /s,1 0 -2 /s).The stress-strain curves and energy absorption characteristics were analysed.Moreover,size effect model of concrete strength in consideration of strain rate effect was established based on Bazant size effect theory.Results suggest that the mechanical properties of concrete display obvious size effect and rate effect;the energy absorption capacity per unit volume of concrete de-creases with the increase of specimen size,and when the strain rate is small,the energy absorption capacity increa-ses,but after strain rate exceeds a certain value,the increment of energy absorption capacity is not obvious;the strain softening of concrete intensifies along with the increase of specimen size,and the strain softening after peak depends on the specimen’s geometry size.
出处
《长江科学院院报》
CSCD
北大核心
2015年第5期132-136,共5页
Journal of Changjiang River Scientific Research Institute
基金
三峡大学培优基金项目(2014PX014)
关键词
混凝土
尺寸效应
速率效应
应变软化
抗压性能
吸能特性
concrete
size effect
rate effect
strain softening
compressive performance
energy absorption characteristic