早期负温养护环境下橡胶混凝土强度发展及抗氯离子渗透性能研究

Study on Strength Development and Resistance to Chloride Ion Penetration of Rubber Concrete at Early Negative Temperature

为研究橡胶颗粒粒径、掺量以及防冻剂对负温下橡胶混凝土性能的影响,将40目和80目两种粒径的橡胶粉,按直接添加的方式制备橡胶掺量为0kg/m^3、10kg/m^3、20kg/m^3、30kg/m^3的橡胶混凝土,进行抗压强度试验分析混凝土早期受冻后强度的变化,并进行抗氯离子渗透(RCM)试验,分析早期受冻对橡胶混凝土氯离子渗透性能的影响,结合SEM图对强度变化及氯离子渗透机理做深入的分析。结果显示,在相同预养时间和早期受冻环境的件下,橡胶混凝土抗压强度均低于普通混凝土,但掺加防冻剂后,橡胶粉掺量越多、预养时间越短,抗冻性能越优;早期受冻后,橡胶混凝土氯离子渗透系数较普通混凝土增长幅度小,掺量为30kg/m^3的40目、80目橡胶混凝土氯离子渗透系数是标准养护条件下的1.14倍、1.07倍,相比下80目橡胶混凝土抗氯离子渗透性能更优。

The influence of rubber particles,volume,anti-freezing agents on rubber concrete under negative temperature conditions was studied,using 40 mesh and 80 mesh two kinds of particle size of rubber powder. Rubber concrete with a rubber content of 0 kg/m^3,10 kg/m^3,20 kg/m^3 and 30 kg/m^3 was prepared by directly adding rubber powder,compressive strength was carried out to investigate the change of concrete after early freezing,analyzing the early cold chloride ion penetration of rubber concrete by RCM testing.Combining SEM images to further analyze the compressive strength changes and chloride ion penetration mechanism. The results show the follows,rubber concrete compressive strength is lower than ordinary concrete at the early cold environment. Under the same pre-curing time and early cold environment,the compressive strength of rubber concrete is lower than the ordinary concrete,and after adding anti-freezing agents,the more rubber powder is added,the shorter the pre-curing time,the better the antifreeze performance. After early freezing,the chloride ion permeability coefficient of rubber concrete is smaller than the ordinary concrete,under the same conditions,the chloride ion permeability coefficient of 40 mesh and 80 mesh rubber concrete with the dosage of 30 kg/m^3 is 1.14 and 1.07 times higher than that under standard curing conditions. Compared with 40 mesh rubber concrete,80 mesh rubber concrete has better chloride ion penetration resistance.