环氧沥青道面高温足尺加速加载动力响应

Acceleration Load Dynamic Response of Full scale Epoxy Asphalt Pavement under the Condition of High Temperature

摘要:

利用MLS66加速加载试验系统对某军用机场试验段2种典型的环氧沥青道面进行足尺加速加载试验.考虑到高温环境影响，将道面加热至60℃，研究2种道面的环氧沥青面层以及沥青混凝土下卧层的动力响应特性.环氧沥青面层响应在加载初期均为拉压交替变化，而加载后期半刚性基层道面以拉应变为主，复合道面以压应变为主；沥青混凝土层均以压应变为主.通过响应结果分析可知，在高温条件下受沥青黏弹性和流变性影响，道面的力学行为和状态随加载次数的增加发生变化；不同力学响应导致环氧沥青道面结构高温条件破坏机理不同，因而设计控制指标亦不同，复合道面控制压应变，半刚性基层道面控制拉应变.

关键词:机场道面; 环氧沥青混凝土; 加速加载; 动力响应

Abstract:

Full scale tests of two kinds of epoxy asphalt pavement structure were carried out using MLS66 accelerated pavement test system at a test section of military airport. Considering high temperature environment, the pavement was heated to 60℃. Dynamic response characteristics was studied under the epoxy asphalt layer and asphalt concrete layer of two pavement structures. Dynamic response of epoxy asphalt layer is in the alternative state of tensile strain and compressive strain at the beginning of the loading, but is the tensile strain for semi rigid base pavement and is the compressive strain for semi rigid base pavement at middle and later periods of the loading. Asphalt concrete layers are predominantly compressive strain. Response analysis shows that mechanical behavior and state of pavement changed with the increase of loading times because of viscoelastic and rheological property of bitumen under the high temperature condition; Different mechanical response of epoxy asphalt pavement structural bring about different failure mechanism under high temperature condition, thus design control indexes are also different. Compressive strain should be controlled for composite pavement and tensile strain should be controlled for semi rigid base level.

Key words:airport pavement; epoxy asphalt concrete; accelerated pavement testing; dynamic response