高速铁路板式无碴轨道用CA砂浆的疲劳特性

Research on the Fatigue Behavior of CA Mortar Used in Ballastless Slab Track of High Speed Railway

CA砂浆是用于高速铁路板式无碴轨道结构的关键材料。研究了CA砂浆分别在环境温度为20℃、-20℃,应力水平为0.9、0.85、0.8、0.75、0.7、0.65,加载频率10 Hz,正弦波加载条件下的疲劳特性。结果表明,研制的CA砂浆疲劳寿命对数值(lgN)与应力水平(S)呈现良好的线性相关性;CA砂浆的抗压强度受环境温度影响较大,相同应力水平条件下,CA砂浆在负温环境中的疲劳寿命低于在常温环境中的,CA砂浆的粘弹性特点保证了CA砂浆在-20℃环境仍具有良好的耐疲劳性能。

CA mortar is the key component in the structure of slab track and its fatigue performance is critical to the durability and safety of high speed railway. The paper investigated its fatigue behavior under different stress levels （0.9, 0.85, 0.8, 0.75, 0.7, 0.65） and temperatures （20 ℃, - 20 ℃ ） with the loading frequency of 10 Hz and the sine wave. Results indicate that the fatigue life of CA mortar is logarithmically linear with stress levels and the viscoelasticity of CA mortar guarantees a good fatigue performance at 20 ℃.