胶粉改性沥青混合料动态和断裂力学性能

Dynamic and Fracture Mechanical Properties of Rubber Powder Modified Asphalt Mixture

文中通过单轴压缩动态模量试验和半圆弯曲断裂试验,研究不同胶粉掺量和细度下混合料动态模量和相位角以及断裂荷载和断裂位移.结果表明:胶粉掺量由10%分别增加到20%和30%以及胶粉细度由20目增加到40目时,混合料动态模量和断裂荷载逐渐增大,相位角和断裂位移逐渐减小.断裂能在胶粉掺量20%和细度40目时分别最大.40目与60目胶粉对应混合料动态和断裂力学性能差异不显著.20℃10 Hz条件下,胶粉掺量在20%时动态模量达12000 MPa,临近规范上限,胶粉掺量过大引起5℃相位角显著降低.综合考虑混合料高低温性能,宜优选胶粉掺量为20%,细度40目.

Through uniaxial compression dynamic modulus test and semi-circular bending fracture test,the dynamic modulus and phase angle,fracture load and fracture displacement of the mixture with different rubber powder content and fineness were studied.The results show that when the content of rubber powder increases from 10%to 20%and 30%respectively,and the fineness of rubber powder increases from 20 mesh to 40 mesh,the dynamic modulus and breaking load of the mixture gradually increase,while the phase angle and breaking displacement gradually decrease.The breaking energy is the maximum when the rubber powder content is 20%and the fineness is 40 mesh,respectively.There is no significant difference in dynamic and fracture mechanical properties between 40 mesh and 60 mesh rubber powder.At 20℃and 10Hz,the dynamic modulus reaches 12000MPa when the rubber powder content is 20%,which is close to the upper limit of the specification.Excessive rubber powder content causes a significant decrease in the phase angle at 5℃.Considering the high and low temperature performance of the mixture,it is appropriate to optimize the rubber powder content of 20%and the fineness of 40 mesh.