胶粒混凝土耐久性试验研究

Experiment on durability of rubber concrete

胶粒混凝土作为新型材料有着广阔应用前景,但由于对其耐久性研究不足,在很多工程中难以推广应用。本试验以C20普通混凝土为基准,采用三因素（水灰比、胶粒掺量、胶粒粒径）三水平正交设计试验,通过相对性抗渗和冻融试验试验,研究三因素对混凝土抗渗性和抗冻性的影响规律。试验结果表明：胶粒粒径对混凝土抗渗性影响最大,且随着胶粒粒径增大,抗渗性呈间歇性变化,粒径为1.18~2.36 mm时抗渗性最好。加入胶粒对动弹性模量有一定影响,但不会影响其抗冻等级。动弹模量随着胶粒掺量增大而减小,随着胶粒粒径的增大呈先增后减的趋势,最佳水平为1.18~2.36 mm。加入胶粒能明显改善其冻融质量损失率,质量损失率随着胶粒掺量的增大呈间歇性变化,掺量为15%时,质量损失率明显优于基准混凝土。胶粒掺量对混凝土抗冻性影响最大,最优掺量值大约在15%~30%。

Rubber concrete as a new material has a broad application prospect. However, due to lack of its durability study, it is difficult to promote rubber concrete in many engineering applications. The experiment used C20 ordinary concrete as a benchmark, adopted the orthogonal design experiment of three factors （water cement ratio, dosage of rubber particles, rubber particle size） with three levels, carried out relative impermeability and freeze - thaw experiment and studied the influence of three factors on concrete impermeability and frost resistance. The experiment results showed that the rubber particle size has the greatest influence on the permeability resistance of concrete. With the increase of colloidal particle diame- ter, the permeability resistance emerges intermittent changes, the penetration resistance is the best when particle size is 1.18 to 2.36 mm. The addition of colloidal particle has certain effects on dynamic modulus of elasticity, but will not affact their level of antifreeze. The dynamic modulus of elasticity decreases with the increase of colloidal particle content, and appears first increase and then decrease with the increase of colloidal particle size. The optimum level is 1.18 to 2.36 mm. The addition of colloidal particle can obviously improve the loss rate of freeze -thaw quality which appears intermittent change with the increase of colloidal particle content. When content is 15% , the mass loss rate of concrete is obviously better than that of benchmark. The content of colloidal particle had the greatest influence on frost resistance of concrete, the optimum content is from 15% to 30%.