橡胶地聚物混凝土力学性能及阻尼特性试验研究

Experimental study on mechanical properties and damping characteristics of rubber geopolymer concrete

为了研究橡胶地聚物混凝土的力学性能及阻尼特性,基于橡胶颗粒替代体积分数为试验参数,进行了混凝土力学性能试验和悬臂梁在低周反复作用下的自由振动试验,分析了橡胶地聚物混凝土的力学性能随橡胶颗粒替代体积分数变化的影响规律,研究了橡胶地聚物混凝土悬臂梁在不同损伤控制位移下和不同橡胶颗粒替代体积分数下的阻尼性能,建立了悬臂梁阻尼比与损伤指数之间的关系。结果表明:少量的橡胶颗粒能够提高地聚物混凝土抗折强度,改善混凝土的韧性;相同损伤指数的橡胶地聚物混凝土悬臂梁的阻尼比随着橡胶颗粒替代体积分数的增大而增大;随着损伤指数的增大,同一橡胶颗粒替代体积分数下的橡胶地聚物混凝土悬臂梁阻尼比均呈现先增大后减小的趋势;通过分析不同替代体积分数下的橡胶地聚物混凝土的弯曲动刚度、损伤指数及阻尼比和损伤指数之间的关系,采用替代体积分数为10vol%的橡胶颗粒不仅可以增强橡胶地聚物混凝土悬臂梁的阻尼特性,而且其刚度退化规律具有可控性。

To investigate the mechanical properties and the damping performance of the rubber geopolymer concrete,the concrete mechanical performance test and the free vibration test of the cantilever beam under the low cyclic action were done based on the replacement volume fraction of the rubber particles for the test parameters.The influence law of the rubber geopolymer concrete with the variation of the replacement volume fraction of the rubber particles was analyzed.The damping performance of the rubber geopolymer concrete cantilever beam under the different damage control displacement and the different replacement volume fraction of the rubber particles was studied.The relationship between the damping ratio and the damage index of the cantilever beam was established.The results show that a small amount of the rubber particles can enhance the flexural strength and improve the toughness of the geopolymer concrete.The damping ratio of the rubber geopolymer concrete cantilever beam with the same damage index increases with the increase of the replacement volume fraction of rubber particles.With the increase of the damage index,the damping ratio of the rubber geopolymer concrete cantilever beam increases first and then decreases under the same replacement volume fraction of the rubber particles.By analyzing the bending dynamic stiffness,the damage index and the relationship between the damping ratio and the damage index of the rubber geopolymer concrete with the different replacement volume fraction of the rubber particles,it is found that the rubber particles with 10vol%replacement volume fraction can not only enhance the damping characteristics of cantilever beam,but also its stiffness degradation law is controllable.