Performance Of Porous Elastic Road Surface Materials Based On Interfacial Activation Method

Porous elastic pavement(PERS)is a noise-reducing pavement in which rubber granules replace part of the aggregate,and polyurethane replaces asphalt as the cementing material.PERS has excellent noise reduction effect,but the internal material interface of the mixture is easy to be damaged under load.Increasing the amount of polyurethane will increase the cost,so the mixture materials needs to be optimized.Based on molecular dynamics,The effects of different interface modification methods on the interface bonding ability of PERS mixtures are simulated,and the results of molecular dynamics simulation are verified through laboratory experiments,in order to provide guidance for the optimization of porous elastic pavement mixtures.First,using molecular dynamics simulation methods,the adhesion performance between various modified rubbers and polyurethanes was studied,and it was found that for natural rubber(NR)and styrene-butadiene rubber(SBR),the introduction of oxygen-containing groups(carbonyl,hydroxyl)increases the surface hydrophilicity of the rubber material and improves the interface energy between the rubber material and the polyurethane.Similarly,the simulation analyzed the adhesion between different mineral aggregates,two inorganic anti-stripping agents and polyurethane.The results show that the order of the mineral aggregates interacting with polyurethane from strong to weak is: basalt>granite>marble≈quartzite>limestone.Cement can improve the adhesion between limestone or basalt and polyurethane,while lime can only improve the bond between limestone and polyurethane.Secondly,based on infrared spectroscopy detection and hydrophilicity observation,the rubber granules treated by three activation measures(ultraviolet ozone treatment,sodium hydroxide solution immersion,potassium permanganate solution immersion)were tested,and it was found that new oxygen-containing groups appeared on the surface of the rubber granules,and the hydrophilicity was significantly improved.Finally,through indoor experiments,samples of porous elastic mixtures with different interfaces modified were prepared,the road performance of the mixtures were tested,and the molecular dynamics simulation results were verified.It is found that the three rubber modification measures can improve the splitting strength,anti-scattering ability and water stability of the mixture,and the improvement effects of the three modification methods are not much different;the material performance of the mixture specimens using basalt is stronger than that of the limestone aggregate.The addition of two inorganic anti-stripping agents can significantly improve the material performance,of which cement improves the material performance the most.Prepare the test piece using modified rubber(24h ultraviolet ozone treatment),and add 0.5% cement as the aggregate interface modifier.The test piece was prepared according to the above scheme,and the test showed that the splitting tensile strength was increased by 42.3%,the flying loss rate was reduced to 7.0%,and the splitting freeze-thaw rate was increased to 73.11%.Using molecular dynamics methods,combined with microscopic observation methods and laboratory experiments to simulate and analyze the effects of different interfaces in the porous elastic mixture and the effects of various interface modification measures,which provides a new idea for the optimal design of porous elastic pavement materials.