橡胶环氧沥青碎石防水黏结层抗剪性能研究

为了研究钢桥面铺装用橡胶环氧沥青碎石(REAS)防水黏结层的抗剪性能,并分析其与桥面坡度及环境温度频繁变化的关系,进行不同剪切角度和不同冻融循环次数的斜剪试验,通过剪切界面正应力与抗剪强度的线性拟合关系计算REAS防水黏结层的黏聚力及内摩擦角,并基于能量法理论对其剪切耗散能进行研究.结果表明:添加橡胶粉的环氧沥青黏结料(EA)体系内形成了新的化学交联和物理缠结,表现出更好的黏结性能、抗变形能力和低温柔韧性;不同的剪切角度及冻融循环次数下,REAS防水黏结层的抗剪强度及剪切位移均大于EA防水黏结层,表现出更好的抗剪性能.同时,REAS防水黏结层的抗剪强度随着剪切角度的增加呈幂函数减小趋势,随冻融循环次数的增加呈抛物线型衰减,5次冻融循环后,REAS防水黏结层的剪切耗散能相对于未冻融循环的剪切耗散能减小了46.0%,说明冻融循环对REAS防水黏结层的抗剪性能影响显著.

Shear Performance of Waterproof Cohesive Layer of Rubber Epoxy Asphalt Stone

This paper studied the shear performance of waterproof cohesive layer of a rubber epoxy asphalt stone (REAS)on steel deck pavement, and examined the relationships between the shear performance and the frequent change of bridge slope and environment temperature. Firstly, the oblique shear tests were conducted under different shear angles and freeze-thaw cycle times. Considering the linear relationship between normal stress and shear strength, the cohesive force and the internal friction angle of REAS waterproof cohesive layer were calculated. According to the energy method, shear dissipated energy was analyzed. The test results showed that new chemical cross linking and physical entanglement occurred in the epoxy asphalt binder with rubber power, which exhibits better bonding performance, anti-deforming capability and cryogenic flexibility. Under different shear angles and freeze-thaw cycle times, the shear strength and shear displacement of REAS waterproof cohesive layer were greater than those of EA waterproof cohesive layer. It is demonstrated that the REAS waterproof cohesive layer has better shear performance. On the other hand, the shear strength of the REAS waterproof cohesive layer decreased as a power function with the increase of the shear angle, while it decreased as a parabolic curve with the increase of freeze-thaw cycle times. After five freeze-thaws cycle times, the shear dissipated energy of REAS waterproof cohesive layer decreased by 46.0%, which indicates that the freeze-thaw cycles significantly influenced the shear performance of REAS waterproof cohesive layer.