低温环境中水工沥青混凝土动态抗压性能研究

为研究低温环境中水工沥青混凝土在地震作用下的动力特性及破坏模式,在不同温度和应变率下对水工沥青混凝土现场芯样进行了动态抗压试验,深入分析了温度和应变率对水工沥青混凝土的破坏形式、应力应变特性、峰值应力及弹性模量等力学性能的影响。结果表明,随着应变率的增加,水工沥青混凝土的破坏模式由微裂纹破坏、拉剪破坏过渡至劈裂破坏,应力应变曲线由应变硬化型向应变软化型转变,抗压强度和弹性模量也随之增大;随着温度的降低,水工沥青混凝土强度和刚度明显增大,具有明显的低温硬化效应。此外,基于试验结果建立了沥青混凝土的动态本构模型,该模型参数较少且与试验结果吻合度较高,具有一定的实用性。

Investigation of Dynamic Compressive Properties of Hydraulic Asphalt Concrete under Low Ambient Temperature

In order to study the dynamic mechanical properties and failure modes of hydraulic asphalt concrete, dynamic compressive tests of specimens drilled out of the field site were carried out under the seismic strain rates and low temperature environment. The effects of temperature and strain rate on failure modes, stress-strain characteristics, peak stress and elastic modulus of hydraulic asphalt concrete were analyzed. The results show that with the increase of strain rate, failure modes of hydraulic asphalt concrete transited from microcrack failure, tension-shear failure to splitting failure, the stress-strain curve changed from strain hardening to strain softening, and the compressive strength and elastic modulus also increased. With the decrease of temperature, the strength and stiffness of hydraulic asphalt concrete increased obviously, which had obvious low temperature hardening effect. In addition, a dynamic constitutive model of hydraulic asphalt concrete was established based on the test results, which has fewer parameters and is in good agreement with the test results. Thus, it has a certain practicability.