偏高岭土改性NaOH预处理橡胶混凝土抗盐冻性能及寿命预测

Salt Freezing Resistance and Life Prediction of Metakaolin Modified NaOH Pretreated Rubber Concrete

摘要:

利用氯盐与冻融循环耦合的方式模拟盐冻环境，探究了盐冻过程中偏高岭土（MK）对NaOH预处理橡胶混凝土物理力学性能及使用寿命的影响.结果表明：在盐冻过程中，改性橡胶混凝土的物理力学性能明显优于橡胶混凝土；MK增加了水化产物总量，细化了孔隙结构，增加了水分在混凝土内的迁移难度，加之橡胶颗粒自身弹性对冻胀应力的消解作用，因而降低了改性橡胶混凝土在盐冻环境中的损伤程度；当MK掺量为15%时，改性橡胶混凝土的抗盐冻性能最佳，其Weibull函数预测寿命可达475次冻融循环.

Abstract:

The coupling of chloride salt and freeze-thaw cycle was used to simulate the salt freezing environment. The effects of metakaolin（MK） on the physical and mechanical properties of NaOH pretreated rubber concrete during salt freezing were studied， as well as its service life. The results indicate that modified rubber concrete exhibits significantly better physical and mechanical properties than rubber concrete during salt freezing. MK significantly increases the total amount of hydration products， refines the pore structure， and reduces damage to modified rubber concrete in salt freezing environments. The dissolution effect of rubber particle elasticity on frost heave stress is a key factor in achieving this improved performance. The optimal MK content for achieving the best salt freezing resistance is 15%，which is predicted to result in a Weibull function life of 475 freeze-thaw cycles.