盐冻融循环作用下低热大体积混凝土损伤特性研究

Investigation on damage characteristics of low heat mass concrete under salt freeze-thaw cycles

对混凝土在盐冻融循环作用下的损伤特征进行了研究,分别制备了普通水泥混凝土、低热混凝土以及掺1%、2%水化热抑制剂的低热混凝土,首先对比研究了养护龄期内的强度形成过程;之后将混凝土进行300次盐冻融循环(5%硫酸盐溶液),每隔25次取出进行测试,计算得到质量损失率与相对动弹性模量。基于随机损伤理论和Weibull分布,建立了低热混凝土在盐冻融循环作用下的损伤演化方程。结果显示:强度形成过程中低热混凝土表现出更好的抗变形能力,但对盐冻融作用敏感性较大。

This paper studied the damage characteristics of concrete under sulfate freeze-thaw(S-F-T).Four kinds of speci-mens were prepared to address this issue:ordinary cement concrete,low heat cement concrete,and low heat cement concrete with 1%and 2%hydration heat inhibition,respectively.Firstly,the strength-forming process among the four kinds of specimens were compared.After that,four kinds of specimens were performed 300 S-F-T cycles in 5%sulfate solutions.The physical and mechanical tests were carried out every 25 cycles to obtain the mass loss rate and the relative dynamic elastic modulus.Based on the stochastic damage theory and Weibull distribution,the damage evolution equation of low heat cement concrete under S-F-T cycles is proposed.The results show that the low heat mass concrete gain better deformation ability in the strength-forming process.However,it is more sensitive to S-F-T.