Research On Composite Pavement Anti-reflective Cracking Application Of Wet Laid Polymer Coiled Materials

Paving asphalt pavement on cement concrete pavement is a common method for repairing old roads,which has high construction efficiency and good paving effect.However,due to the discontinuities(joints and cracks)of cement concrete pavement structure,asphalt overlay usually generates reflection cracks in the early fatigue life.At first,reflection cracks will not cause serious damage to the service performance of the composite pavement,but with the joint action of temperature change and driving load,the cracks often expand rapidly around,provide a channel for rainwater to enter the interlayer,damage the internal structure of the road,shorten the fatigue life of the pavement and increase the maintenance cost.Since the addition of intermediate interlayer can delay the generation and expansion of reflection cracks to a certain extent,the research on the optimization of intermediate interlayer materials is of great significance to prolong the fatigue life of composite pavement.Through indoor and outdoor tests,this paper explores the application of wet laid polymer coiled materials(composed of Dura fiber reinforced mesh,self-adhesive layer I,polymer resin matrix,self-adhesive layer II and point breaking isolation film from top to bottom)to prevent reflection cracks of composite pavement.The main research contents and conclusions are as follows:(1)Through tensile test,the mechanical properties of three kinds of interlayer materials are analyzed.The results show that the maximum tensile elongation of wet laid polymer coiled materials is higher than that of polymer modified asphalt crack resistant paste and geotextile;after thermal aging,the maximum tensile retention rate and maximum tensile elongation retention rate of wet laid polymer coiled materials are higher than those of polymer modified asphalt crack resistant paste.(2)Through peel strength test,the bonding characteristics of wet laid polymer coiled materials are analyzed.The research shows that the hydrophilic groups in the adhesive layer and the hydration products of cement mortar /cement paste form a fiber network structure to seal the gap between the wet laid polymer coiled materials and the structural subject.However,due to the increased brittleness of cement paste after hardening,improving the peeling strength between the sheets and the structural subject is not as good as cement mortar.(3)Through fatigue loading test(medium load,partial load and rolling load),the anti-reflective cracking performance and fatigue life of four overlay structures are analyzed.The research shows that the anti-reflective cracking performance of wet laid polymer coiled materials overlay structure is the best,and the fatigue loading times of initial crack and final crack are more than those of polymer modified asphalt anti cracking overlay structure,geotextile overlay structure and non-interlayer overlay structure.(4)The construction process of wet laid polymer coiled materials is optimized and applied to the experimental road of asphalt overlay on cement concrete pavement.There was no reflection crack on the experimental road.After one and a half years of operation,no reflection cracks have been generated on the experimental road.(5)The secondary reconstruction experimental road of the composite pavement with reflection cracks is paved,and the "trenching" construction method is proposed.The wet laid polymer coiled materials are paved at the exposed joints and cracks of the cement concrete pavement.The experimental road has not generated reflection cracks for half a year.