海洋骨料混凝土力学性能试验研究

Experimental research on mechanical properties of ocean aggregate concrete

为了研究海洋骨料混凝土的力学性能,以海砂取代率、强度等级、减水剂与水泥质量比、复掺矿物掺合料类型、拌养用水和粗骨料类型为变化参数,设计并制作了44组共132个试件,进行轴心受压静力单调加载试验,观察其受力破坏过程及形态,获取试件轴压应力-应变曲线、重要物理及力学性能指标,分析各变化参数对其物理及力学性能指标的影响规律,提出了海洋骨料混凝土各强度指标之间的换算关系式和轴压应力-应变本构方程。结果表明:C30以上强度的海洋骨料混凝土呈珊瑚骨料劈裂破坏形态;各参数对海洋骨料混凝土干密度影响不大,变幅为1 983~2 143 kg/m^(3);海洋骨料混凝土峰值应变范围为3.59×10^(-3)~6.3×10^(-3);随海砂取代率的增加,试件力学性能指标上下波动变化;强度等级对其弹性模量、峰值应力及峰值应变影响显著;复掺偏高岭土和硅灰的海洋骨料混凝土力学性能较好;减水剂与水泥质量比对峰值应变影响显著,但对其他力学性能影响不大,变幅在14%以内;拌养用水对其峰值应力有一定影响;珊瑚粗骨料混凝土的延性及耗能均小于同强度的碎石混凝土,差幅为6%~48%。

In order to research the mechanical properties of ocean aggregate concrete,132 specimens were designed to carry out axial compression tests with the change parameter(sea sand percentage,strength grade of concrete,ratio of water reducer to cement,type of mineral admixtures,stirring and curing water and types of coarse aggregate).The failure modes of specimens were observed.The stress-strain curves,important physical properties and mechanical properties of the specimens were obtained.The influence of changing parameter on its physical and mechanical properties was analyzed.The stress-strain constitutive relationship and relationship between compression strength of cylinder and cubic of ocean aggregate concrete was fitted.The results show that ocean aggregate concrete with strength above C30 is in the form of coral aggregate splitting failure.Variable parameters have little effect on dry density of ocean aggregate concrete,and its range is 1 983~2 143 kg/m^(3).Peak strain range of ocean aggregate concrete is 3.59×10^(-3)~6.3×10^(-3).With the increase of sea sand percentage,the mechanical properties index of ocean aggregate concrete fluctuates upward and downward.The strength grade of concrete has significant effects on the elastic modulus,peak stress and peak strain of concrete.Ocean aggregate concrete has better mechanical properties when mixed with high territory and silica fume.The mass ratio of water reducer to cement has a significant effect on peak strain.However,it has little effect on other mechanical properties,with a variation of less than 14%.Stirring and curing water has a certain influence on peak stress.The ductility and energy consumption of coral coarse aggregate concrete are less than those of gravel concrete with the same strength,the difference is 6%~48%.