公路沥青混凝土材料加载力学破坏试验

Experimental on Loading Mechanical Failure of Highway Asphalt Concrete Materials

为探讨保定环城快速公路沥青混凝土材料力学特征影响变化,针对工程实际,设计了高温热作用及低温抗冻防裂剂掺量两个试验因素,开展了三轴力学加载破坏试验。试验表明,抗冻裂剂对混凝土承载应力有削弱作用,尤其掺量超过3%后更为显著,同时掺量愈多,试样峰值应力后降幅愈大。由试验分析得到,温度热作用对沥青混凝土影响应分为两部分,温度低于100℃时,峰值应力随温度梯次具有平均增幅21.5%,而温度超过100℃后,热作用呈损伤效应;控制围压,有助于限制温度热作用影响。研究表明,黏聚力受温度热作用影响较显著,而内摩擦角与抗冻裂剂密切相关。

In order to explore the influence of mechanical characteristics of asphalt concrete materials on Baoding Ring Expressway,according to the engineering practice,two test factors of high temperature thermal action and low temperature anti-freezing crack agent were designed,and triaxial mechanical loading failure test was carried out.The test results show that the anti-freezing crack agent has a weakening effect on the bearing stress of concrete,especially when the content is more than 3%,and the more the content is,the stronger the ductility of the specimen.According to the experimental analysis,the influence of temperature and thermal action on asphalt concrete can be divided into two parts.When the temperature is lower than 100℃,the thermal action can promote the bearing stress,while when the temperature is higher than 100℃,the thermal action has a damage effect;The control of confining pressure helps to limit the influence of temperature and thermal action.The results show that the cohesion is significantly affected by temperature and heat,and the internal friction angle is closely related to the anti-freezing crack agent.