沥青混凝土面板低温疲劳破坏的实验研究

A EXPERIMENTAL STUDY ON FATIGUE DAMAGE OF ASPHALT CONCRETE FACING AT LOW TEMPERATURE

我国北方地区的土石坝和水池的防渗沥青混凝土面板,常出现低温裂缝。因此,对沥青混凝土在低温条件下的温度应力疲劳进行实验研究很有必要.本项研究研制了适用于沥青混凝土低温低周大变形的弯曲疲劳试验机,进行了沥青混凝土在不同低温下的疲劳破坏性能试验。对试验结果用粘弹性理论和推广的应变区分法(SRP)和应变能区分法(SEP)进行了分析,首次得出了沥青混凝土的疲劳寿命与弯曲应力、应变和应变能的关系,并试用于实际工程的予测.

Asphalt concrete temperature stress fatigue characteristics are studied at low temperature, since low temperature cracks often occur n asphalt concrete facings of rockfill dams and reservoirs in the north china. For this purpose, a fatigue machine worked under low temperature and low frequency constant bending stress, and suitable for big deformation test is developed. A series of tests on fatigue damages of asphalt concrete are carried out on the machine and the test results are analysed by using the theory of visco-elasticity and the SRP(strain range partition) and the SEP(strain energy partition). The relationships of fatigue life versus bending stress, strain and strain energy are given for the first time and fatigue life of a facing is predicted for a real engineering project.