摘要
为获得沥青混合料的断裂特性,改进了传统overlay tester试验的加载方式、试验模具和控制系统等,提出了在沥青混合料性能试验机(AMPT)上进行沥青混合料断裂试验的方法.为验证该新型断裂试验方法的有效性,拟定了1,2,3和4 mm/min 4个断裂加载速率进行验证.试验结果表明:在低速率加载条件下,沥青混合料呈现蠕变特征;在高速率加载条件下,沥青混合料断裂扩展特性不显著;在中间速率3mm/min加载条件下,试验能够有效区分断裂的裂缝萌生、裂缝扩展和完全断裂的3个断裂过程.此外,提出了断裂能、拉伸强度和拉伸模量等8个断裂参数评价沥青混合料的断裂特性.改进后的overlay tester试验,为研究沥青混合料断裂特性提供了一个新的方法.
To determine the fracture characteristics of asphalt mixture a novel fracture test with modified loading modes loading fixtures and the control system of the conventional overlay tester is implemented by the asphalt material performance tester AMPT .In order to evaluate the validity of the proposed fracture test four different loading rates including 1 2 3 and 4 mm/min are examined in the AMPT. The results indicate that the fracture behavior is similar to creep at a low loading rate and does not show significant marginal tail extension at a high loading rate.It clearly shows the phase of crack initiation crack propagation and fracture at a loading rate of 3 mm/min. Besides eight fracture parameters such as fracture energy tensile strength and tensile modulus are applied to evaluate the fracture characteristics of asphalt mixture.Development of the overlay tester for the fracture test of asphalt mixture can be considered as a new fracture test of asphalt mixture.
基金
The National Natural Science Foundation of China(No.51178114)
the Chinese Western Transportation Construction Technology Project of Transportation Ministry(No.2009318000086)
