Investigation On Road Performance Of Carbon Fiber Modified Asphalt And Asphalt Mixture

Asphalt pavement is prone to smashing,cracking,surface damage and other diseases during use,which seriously affects its durability.As a kind of external additive modifier commonly used in asphalt and asphalt mixtures,fiber materials can significantly improve their road performance by incorporating into asphalt cement.Carbon fiber has excellent physical and mechanical properties,but its research results in pavement engineering are still rare.In view of this,this paper will systematically carry out research on the road performance of carbon fiber modified asphalt and asphalt mixture,in order to provide basis for the application of carbon fiber in asphalt pavement engineering.In order to study the road performance of carbon fiber asphalt cement,carbon fiber asphalt cement samples were prepared by adding carbon fibers of different lengths to asphalt in different dosages.The shear resistance was measured by the penetration test.The low temperature performance was evaluated by the ductility test.The resistance to rutting deformation was evaluated by dynamic shear rheological test(DSR).The high temperature flow of asphalt cement was analyzed by Brinell rotational viscosity test.The performance is changed,and the influence of fiber dosage,fiber length,temperature and powder-to-gel ratio on the performance of asphalt cement is obtained.The AC-13 type grading was selected,and the carbon fiber with different dosage and different length was blended into the asphalt mixture.The Marshall test was used to analyze the effect of carbon fiber with different dosage and length on the physics-mechanical index of asphalt mixture Marshall.And determine the best ratio of oil to stone for each group of carbon fiber asphalt mixture.On this basis,the rutting test,trabecular low temperature bending test and freeze-thaw splitting test were used to study the high temperature stability,low temperature crack resistance and water stability of carbon fiber asphalt mixture.Studies have shown that with the increase of carbon fiber content and fiber length,the asphalt cement penetration value is significantly increased,the shear resistance is obviously improved,carbon fiber can improve the rheology of asphalt cement;after carbon fiber is blended,asphalt cement shear Both the modulus of cut and the rutting factor increased,indicating that it has improved resistance to rutting.Under low temperature conditions,the ductility of carbon fiber asphalt cement decreased to some extent and the brittleness increased.The optimum carbon fiber length in the AC-13 carbon fiber asphalt mixture is 3 mm and the dosage is 1.0%.The carbon fibers are distributed in a multi-directional manner inside the asphalt cement,which form a three-dimensional network structure and form a thickening,toughening and reinforced effect in the asphalt mixture.