Research On Optimization Of Material Composition And Service Performance Of Polyurethane Mixture

With the continuous promotion of sponge city and green highway construction concept,the requirements for functionality and comfort of roads are higher and higher.In order to meet the functional requirements of road,this paper uses polyurethane binder,stone and rubber particles as raw materials,and obtains a super elastic porous polyurethane mixture with certain mix proportion and molding method.Compared with ordinary asphalt mixture,it has the characteristics of large void ratio and high rubber particle content.The mixture is prone to large deformation under the action of vehicle load,so as to realize self-stress deicing function,which can effectively reduce the noise between tire and pavement,and is suitable for rainy areas.First of all,by changing the size of coarse aggregate,porosity and large porosity loss range,the porosity and porosity of the mixture are determined by changing the size of coarse aggregate,porosity and large porosity loss;The viscosity temperature curve of polyurethane binder was studied by Brinell viscometer to determine the best mixing temperature and compaction temperature range of polyurethane;the void fraction VV,bulk density and flying loss rate of super elastic porous polyurethane mixture were tested,and the best compaction times were determined by curve inflection point;the rubber particles and aggregates were mixed with polyurethane binder by internal mixing method;based on the equal volume,the rubber particles and aggregates were added into the polyurethane binder The replacement method was used to replace the aggregates with different particle sizes;the mechanical properties of rubber particles with different grades were tested by water immersion flying test,water immersion Marshall test and freezethaw splitting test to determine the replacement order of rubber particles.Secondly,the temperature and humidity variation range of major cities in China was investigated,and the curing law of mixture was studied by simulating different temperature and humidity conditions in constant temperature and humidity box;five different types of polyurethane,different rubber particle replacement amount(0%,10%,20%)and different void ratio(16%,19%,22%,25%)were used as control group The high temperature stability,low temperature crack resistance,water stability,fatigue performance and skid resistance of the super elastic porous polyurethane mixture were evaluated by rutting test,-10℃ beam bending test,freeze-thaw splitting test,water immersion test,fatigue test and Rockwell friction coefficient test.Finally,based on the three research levels of different types of polyurethane,different void fraction and different rubber particle content,the standing wave tube method is used to test the vertical incidence sound absorption coefficient of the mixture,so as to evaluate its noise reduction performance.ABAQUS finite element software was used to simulate different polyurethane elastic material layer thickness,different polyurethane elastic modulus and different ice thickness,and the influence of different factors on the self stress deicing effect of polyurethane pavement was analyzed;the drainage test was conducted by using pavement water permeameter,and the drainage performance of polyurethane mixture was evaluated by measuring the water seepage within the specified time and calculating the water permeability coefficient Under the engineering environment,the optimal replacement volume ratio of rubber particles and the optimal void ratio of mixture were determined to determine the optimal material composition design of super elastic porous polyurethane mixture.