全珊瑚混凝土的脆性评价

Brittleness evaluation of coral concrete

全珊瑚混凝土由珊瑚骨料、水泥、减水剂及海水按一定配合比制成。为了研究珊瑚混凝土脆性特征及其因素影响,利用MTS电液伺服试验机开展珊瑚混凝土系统压缩试验,获得不同尺寸、不同围压和不同加载速率下珊瑚混凝土全应力-应变曲线.基于Tarasov脆性指数定量评价了珊瑚混凝土的脆性特征及其影响因素.结果表明,珊瑚混凝土脆性普遍大于同一等级的普通混凝土,且强度等级越低两者差异越大;随着高径比、加载应变率或强度等级的提高,珊瑚混凝土的脆性指数逐渐降低,脆性增强,而围压的增大则使其趋于延性破坏.Tarasov脆性评价方法能够合理表征珊瑚混凝土脆性及其尺寸、围压和应变率效应.

The coral concrete is made of coral aggregate,cement,water reducing agent and seawater in a certain proportion.To estimate the brittle characteristics of coral concrete and its influencing factors,the systematic compression tests of coral concrete were conducted utilizing MTS electro-hydraulic servo-controlled testing apparatus.The complete stress-strain curves of coral concrete with different sizes under different confining pressures and different loading rates were obtained.The brittle characteristics of coral concrete and its influencing factors were quantitatively assessed based on Tarasov brittleness index.The results indicate that the brittleness of coral concrete is generally higher than that of conventional concrete at the same strength grade.The lower the strength grade is,the greater the difference between them is.With the increase of aspect ratio,loading strain rate or strength grade,the brittleness index of coral concrete gradually decreases(brittleness increases),while with the increase of confining pressure,the failure of coral concrete tends to be ductile failure.Tarasov brittleness may be adopted to reasonably characterize the brittleness of coral concrete and the effect of size,confining pressure and strain rate on brittleness.