循环荷载历史下CA砂浆的动态受压试验研究

Experimental Research on the Dynamic Compressive Behaviors of CA Mortar Due to Cyclic Loading History

研究目的:为研究历经不同循环荷载历史和不同应变速率对铁路轨道系统CRTSI型板式无砟轨道水泥乳化沥青砂浆(CA砂浆)的抗压强度、弹性模量和峰值应变的影响规律,进行CA砂浆圆柱体试件历经循环加载历史后,在应变速率为1×10^(-5)~1×10^(-2)s^(-1)时的单轴受压特性试验。研究结论:(1)应变速率和循环荷载历史对CA砂浆的力学性能影响显著;(2)CA砂浆的抗压强度、弹性模量和峰值应变均随应变速率的增大而提高;(3)在相同的应变速率下,CA砂浆的抗压强度随循环荷载次数和循环荷载幅值的增加而降低,最大降低幅度为8.34%;(4)当循环荷载幅值较小时,CA砂浆的弹性模量随循环荷载次数的增加而增大,最大增加幅度为59.17%;(5)在相同的应变速率下,CA砂浆的峰值应变随循环荷载次数及循环荷载幅值的增大呈降低趋势,且应变速率对峰值应变的影响小于循环荷载历史的影响;(6)该研究成果为进一步了解历经循环加载历史后板式无砟轨道的力学性能提供必要的试验依据,进而应用于指导CA砂浆材料优化设计中。

Research purposes： In order to analyze the influence on the change rule of compressive strength, elastic modulus and peak strain of China railway track system （CRTS） I slab track cement asphalt mortar （CA mortar） by different cyclic loading histories and strain rates. The uniaxial compression characteristic test of CA mortar cylinder specimens due to cyclic loading histories with the strain rates ranging from 1× 10^ -5s ^-1 to 1 × 10 ^-2s ^-1 was carried out. Research conclusions： （ 1 ） The mechanical property of CA mortar is affected obviously by strain rates and cyclic loading histories. （2） The compressive strength, elastic modulus and peak strain of CA mortar are increase with the strain rate. （3） The compressive strength of CA mortar decreased with the increase of cyclic loading number and cyclic loading amplitude under the same strain rates, the largest reduction of average compressive strength is 8.34%. （4）The elastic modulus of CA mortar increased with the cyclic loading number when the cyclic loading amplitude is small, the largest increase of average elasticity modulus is 59.17%. （5）The peak strain of CA mortar decreased with the increase of cyclic loading number and cyclic loading amplitude under the same strain rates, and the influence of the strain rate on the peak strain of CA mortar is lower than that of the load history. （6） The research results could provide the necessary experimental basis to learn more about the mechanical properties of slab track after different cyclic loading histories, and be applied to the optimal design of CA mortar.