摘要
随着我国高速铁路的持续建设和投入运营,CA砂浆充填层不断出现破坏,经调研发现,充填层的破坏多与水有关。将CRTSⅠ型CA砂浆浸泡在5、20、40℃和60℃的恒温清水中,当浸泡到7、28 d和90 d时,用万能试验机做单轴压缩试验,分析其力学性能变化和破坏机理。结果表明:随浸泡时间增加,CA砂浆的抗压强度和弹性模量均逐渐降低,并且在前28 d下降速度快,幅度大,原因归结于CA砂浆在前28 d吸水基本饱和,后期吸水较少;随浸泡温度的升高,浸泡7 d的CA砂浆,与浸泡28 d和90 d的相比,弹性模量表现出不同的变化规律,分析原因,在浸泡早期,硬化浆体中未水化水泥颗粒遇水继续水化起主要作用,随浸泡时间增长,水对沥青-水泥水化产物界面和沥青-砂界面黏结力的破坏发挥主导作用。
With the continued construction and operation of high-speed railway in China, the frequent destruction of CA mortar filling layer occurs, which is closely related to water as indicated in the research. The uniaxial compression test is carried out with a electronic universal test machine when CRTS （ china railway track system） typeIcement asphalt mortar （ CA） specimens are immersed in water at the temperature of 5, 20, 40 ℃ and 60 ℃ for 7 d, 28 d and 90 d to analyze the changes of mechanical properties and mechanism of destruction. The test results show that with the increase of soaking time the pressure strength and elasticity modulus of CA mortar are reduced gradually, and tend to be faster with great amplitude specifically during the preceding 28 d. The reason is that during the preceding 28 d, CA mortar is saturated with water almost completely and absorbs a little afterwards. Compared with CA specimens soaked for 28 d and 90 d, the elasticity modulus of those soaked for 7 d change irregularly. The reasons which lead to this phenomenon are： in the early stage, the hydration reaction of cement continues in the water where the cement grain not hydrated in the hardened mortar meets with water;with increased soaking time, the destruction of asphalt-cement hydration interface and asphalt-sand interface is caused mainly by water.
出处
《铁道标准设计》
北大核心
2015年第2期40-42,共3页
Railway Standard Design
基金
国家自然科学基金(51208439)
中央高校基本科研业务费专项资金资助项目(2682013CX043)
关键词
CA砂浆
浸泡
温度
力学性能
CA mortar
Immersion
Temperature
Mechanical property
