Preparation And Performance Research Of Semi-flexible Pavement Material Based On Bio-asphalt

Semi flexible pavement refers to the pavement formed by pouring cement paste into the asphalt mixture with large voids.Although this pavement structure combines some advantages of asphalt mixture pavement and cement concrete pavement,due to the high brittleness of the pouring paste after hardening,its low-temperature crack resistance is poor,and cracks are more likely to occur,and the service life of the pavement is seriously reduced.Finally,by verifying the road performance of semi-flexible pavement materials based on biological asphalt under different asphalt cement ratios,the appropriate engineering application scenarios of semiflexible pavement materials under different asphalt cement ratios are obtained.The main research contents include:(1)The primary sources of the mechanical properties of C A mortar were clarified,and the influence of asphalt emulsion type,the asphalt-cement ratio on cement hydration,and the influence of asphalt-cement ratio on the overall performance of CA mortar were comprehensively analyzed.(2)Select liquid bio-asphalt to modify traditional emulsified asphalt,determine the optimum content of bio-asphalt to be 15%through a macro performance test,and confirm that the modification mechanism is physical modification through ATR-FTIR microscopic analysis;based on different asphalt cement ratios,the optimal mix proportion of CA mortar under each asphalt-cement ratio is obtained.The effect of emulsified asphalt on cement hydration was analyzed by hydration heat,TG-DSC,XRD,and SEM.(3)The matrix asphalt mixture gradation with the target void ratio of 25%was obtained by the volume method,and the optimum asphalt usage was determined to be 3.0%by the leakage test and scattering test;According to the evaluation index of the perfusion rate,it was determined that the average perfusion rate of the slurry reached 97.2%,and the perfusion efficiency was high.(4)The pavement performance of semi-flexible pavement materials based on biological asphalt under different asphalt-cement ratios is studied,and the results show that materials have excellent high-temperature stability,and the dynamic stability is greater than 6000 times/mm;The addition of bio-asphalt improves the low temperature cracking of semi-flexible pavement materials.CASP25 and CASP15 series asphalt mixtures can be used in cold winter and cold winter(warm)areas,respectively;the semi-flexible pavement material’s water stability and anti-skid performance are good.