掺加碳纤维和石墨粉对整体道床轨枕端部温度应力影响研究

Study on effect of carbon fiber and graphite powder on temperature stress sleeper end of monolithic track bed

基于西北地区的实际环境条件,对掺加改性材料与普通混凝土整体道床轨枕端部的温度应变进行了试验检测;将试验测得的应变值进行温度修正后,通过温度应力计算理论,计算了整体道床轨枕端部在凝结硬化阶段至180 d龄期温度变化过程中的温度应力,总结凝结硬化阶段后至180 d龄期内轨枕端部温度应变与应力分布规律,进而研究碳纤维和石墨粉共同作用对整体道床轨枕端部温度应力的影响。结果表明:混凝土中掺入一定量的碳纤维和石墨粉确实能起到减小道床轨枕端部温度应变与应力的作用,可为西北大风干燥条件下整体道床轨枕端部变形与已有裂缝的防治提供参考。

Based on the actual environmental conditions in Northwest China,the temperature strains sleeper end of monolithic track beds which are placed with ordinary concrete and carbon fiber and graphite powder modified concrete are tested respectively.After the strain value measured by strain gauge modified by temperature,through the theory of temperature stress calculation,the thermal stress of the end of sleeper of monolithic track bed is calculated which changed by the temperature during the setting and hardening stage to 180 d old.The distribution of temperature strain and stress at the end of sleeper during the period from the setting hardening stage to 180 d is summarized,and then the effect of carbon fiber and graphite powder on the temperature stress at the end of sleeper is studied.The results shows that adding the carbon fiber and graphite powder into the concrete can reduce the effect of temperature strain and temperature stress at the end of the sleeper,which can be a reference for the prevention and treatment of deformation and existing cracks at the end of the sleeper under the condition of strong wind and dry in Northwest China.