沥青胶浆拉伸全曲线的试验研究

EXPERIMENTAL RESEARCH OF THE WHOLE TENSILE CURVE FOR BITUMINOUS MORTAR

细观尺度上,沥青混合料是由沥青胶浆、粗骨料和孔隙等构成的多相复合材料,而沥青胶浆的力学参数为沥青混合料进行细观尺度研究的重要部分,对抗拉强度有着决定性的影响.本文通过设计制作加载夹具针对不同温度和不同加载速率的条件,对9组试件进行拉伸试验,得到沥青胶浆拉伸全曲线.通过对沥青胶浆拉伸全曲线的研究和计算,确定了沥青胶浆的最大破坏应力σ_(max)、刚度K_(nn)和破坏位移U,这些参数为采用粘聚带本构模型模拟沥青混合料的开裂行为提供了力学参数.

In meso-scale,bituminous mixture consists of bituminous mortar,aggregate and voids.The mechanical parameters of bituminous mortar are important parts of meso-scale properties of bituminous mixture and they have very significant effect on the tensile strength.To this end,a loading fixture is designed.Tensile tests for 9 groups of specimens at different loading rate and temperatures are carried out,and the whole tensile curve for bituminous is obtained.Prom the curve,the maximum tensile stress σ max,the stiffness Knn,and the displacement of failure process U are determined.The parameters obtained are essential to simulate the cracking behavior of bituminous mixture using the cohesive constitutive model.