不同水压作用下的混凝土率效应试验研究

Experimental Study on Rate Effect of Concrete under Different Hydraulic Pressure

利用大型电液伺服多功能动静力三轴仪分析了准150 mm×300 mm的混凝土圆柱体试件在不同水压(0、2、5 MPa和10 MPa)、不同加载速率(10-5、10-4、10-3/s和10-2/s)作用下的力学与变形特性。试验结果表明,混凝土的峰值应力对应变速率的敏感性随围压的增大而增大,峰值应变随围压和应变速率的增大都呈增加的趋势;弹性模量随加载速率的增加总体呈增大趋势,随围压增大变化并不明显;吸能能力随应变速率的增大而增大,而随围压的增大呈先增强后减弱的趋势。

The mechanical and deformable characteristics of φ150mm×300mm mm concrete cylindrical specimens are analyzed by using large electro-hydraulic servo-control function analysis of dynamic and static triaxial under different water pressures （0, 2, 5 MPa and 10 MPa） and different loading rates （10^-5, 10^-4, 10^-3 and 10%） respectively. The test results indicates that, （a） the sensitivity of peak stress of concrete on strain rate increases with the increase of confining pressure, and the peak strain shows a trend of increase with confining pressure and strain rate increases; （b） the elastic modulus shows a trend of increase with loaded rate increase in overall, and changes is not obvious with confining pressure increase; and （c） the energy absorption capacity increases with strain rate increase, and is increased at first and then decreased with confining pressure increase. Key Words： concrete; rate effect test; stress; strain; elastic modulus