水泥乳化沥青砂浆的破坏特性实验

Experimental Research on the Failure Characteristics of Cement Asphalt Mortar

采用万能材料实验机对不同配合比的水泥乳化沥青砂浆(CA砂浆)进行了单轴压缩实验,分析了CA砂浆的典型破坏模式,并进一步研究了破坏模式与微结构参数的定量关系.结果表明:依据不同的物理结构,CA砂浆具有3种典型的破坏模式:(1)A/C≤0.3时,水泥水化物体积多于沥青且超过30%,外力功主要以表面能的形式释放,试件呈劈裂破坏;(2)0.4≤A/C≤0.6时,水泥水化物体积多于沥青,但差值小于30%,沥青的黏性变形消耗了裂缝尖端的能量,表面能降低,试件呈剪切破坏;(3)A/C≥0.7时,水泥水化物体积小于沥青体积,破坏时大部分能量被塑形变形耗散掉,试件呈整体变形破坏.

In this thesis,the stress-strain curves of cement asphalt mortar(CA mortar)with different mix proportions were examined by a universal material testing machine,the failure modes of CA mortar were analysed,and the relationships between the failure mode and microstructure parameter were discussed.The results show that according to the different physical structure,CA mortar possessed three kinds of failure mode,when A/C≤0.3,the volume of cement hydration products was more than 30%of the volume of asphalt,energy formed by external work was mainly released in the form of surface energy,and the splitting failure was the main destruction form.When 0.4≤A/C≤0.6,the volume of cement hydration products was more than the volume of asphalt,but the difference was less than 30%.The increased asphalt consumed the energy of the crack tip through viscous deformation,while the surface energy was reduced,and the shear failure played a leading role.When A/C≥0.7,the volume of cement hydration products was less than the volume of asphalt,most energy was dissipated by plastic deformation during the failure process,and the deformation failure became the main form.