冻融作用对环氧沥青混凝土复合梁抗裂性能的影响

Effect of Freeze-Thaw on Crack Resistance of Epoxy Asphalt Concrete Composite Beams

在中国北方季节性冰冻地区,反复的冻融作用对环氧沥青混凝土的抗裂性能影响较大。分别对7组环氧沥青混凝土试件进行0~30次冻融作用,研究了冻融作用对弯曲劲度模量及复合梁平面应变断裂韧度的影响,分析了不同冻融重复作用下带裂缝的复合梁发生裂缝扩展时的横向应力应变响应和层间黏结状况。研究结果表明:弯曲劲度模量随冻融循环作用的升高而降低;复合梁平面应变断裂韧度、裂缝尖端最大横向拉应力/应变随着冻融重复作用的增加先降低后增高;不同冻融重复作用下带裂缝复合梁断裂不会发生在环氧沥青黏结层。

In the seasonal frost region of northern China,repeated freeze-thaw cycles have great influence on the crack resistance of epoxy asphalt pavement on steel bridge deck.Seven groups of epoxy asphalt concrete specimens were subjected to 0~30 freeze-thaw cycles.The influence of freeze-thaw action on flexural stiffness modulus and plane strain fracture toughness of epoxy asphalt concrete composite beams was studied through laboratory tests and numerical simulation.The transverse stress-strain response and interlayer bonding condition of cracked epoxy asphalt concrete composite beams with cracks under different freeze-thaw cycles were analyzed.The results show that the flexural stiffness modulus of epoxy asphalt concrete decreases with the increase of freeze-thaw cycles,the plane strain fracture toughness and the maximum transverse tensile stress/strain at the crack tip of epoxy asphalt concrete composite beams decrease first and then increase with the increase of freeze-thaw cycles,the fracture of epoxy asphalt concrete composite beams with cracks under different freeze-thaw cycles will not occur in epoxy asphalt bonding layer.