冻融循环下水工混凝土的相对动弹性模量和质量变化规律研究

Research on the relative dynamic elastic modulus and mass variation of hydraulic concrete under freeze-thaw cycle

为了研究冻融循环条件下水工混凝土相对动弹性模量和质量的变化规律,基于混凝土冻融破坏机理和现实情况分析,通过预制混凝土护坡砌块和不同配合比水工混凝土试件的快速冻融试验,分析了质量损失率、相对动弹性模量和冻融循环次数的关系。结果表明:冻融试件质量损失率转为正值时为相对动弹性模量快速降低之时,此时混凝土的含水率为快速破坏含水率;冻融过程中,试件质量前期增加,后期减少,但相对动弹性模量一直降低;可以通过快速修补、防渗处理等方式延缓水工混凝土达到快速破坏含水率,实现提高抗冻性能的目的。

In order to study the changes in the relative dynamic elastic modulus and mass of hydraulic concrete under freeze-thaw cycle conditions,based on the analysis of concrete freeze-thaw failure mechanism and actual situation,the relationship between mass loss rate,relative dynamic elastic modulus,and freeze-thaw cycle number was analyzed through rapid freeze-thaw tests of prefabricated concrete slope protection blocks and hydraulic concrete specimens with different mix proportions.The results show that when the mass loss rate of freeze-thaw specimens turns to a positive value,it is when the relative dynamic elastic modulus rapidly decreases,and at this time,the moisture content of concrete is the rapid failure moisture content.During the freeze-thaw process,the mass of the specimen increases in the early stage and decreases in the later stage,but the relative dynamic elastic modulus keeps decreasing.Rapid repair and anti-seepage treatment can be used to delay the rapid damage of water content in hydraulic concrete,achieving the goal of improving frost resistance.