Study On Design And Pavement Performance Experiment Of Basalt Fiber SMA-13 Mixture

SMA is composed of asphalt binder and a small amount of fiber stabilizer,fine aggregate and more filler composed of asphalt mastic fill in the intermittent graded coarse aggregate skeleton of the gap,composed of asphalt mixture,with good Anti-rutting performance and anti-skid performance,is widely used in highway asphalt pavement structure.Among the constituents of SMA,fibers that play a stable role are particularly important.As the wood fiber is rich in resources,low prices,as the current SMA which is the main fiber stabilizer.With the study found that lignin fiber has easy to absorb water,poor heat resistance,poor wear resistance and other shortcomings,seriously affect the SMA asphalt pavement road performance,so the road researchers continue to explore other high-quality fiber to replace the wood fiber.Based on theoretical research and engineering examples,this paper introduces SMA basalt fiber asphalt mixture.First,the cone penetration,softening point,viscosity and elastic recovery of the asphalt cement were carried out by using the content of basalt fiber with 0%,1%,2%,2.5%,3%,3.5% and 4% The results show that the basalt fiber can improve the ability of the asphalt to resist the temperature change,and with the increase of the content of the asphalt binder,the basalt fiber can improve the asphalt resistance.Increase the effect of improvement is more obvious;deformation recovery capacity has declined,so need to find the appropriate amount of basalt fiber.Then,in order to replace the traditional Marshall test design method with the response surface design optimization method,the content of basalt fiber was 0.25% ~ 0.55%,the fiber length was 3mm ~ 6mm,the ratio of oil to stone was 6.4 ~ 6.8,and the stability,flow value and void Rate,the gap between ore material and the relative density of hair volume as the response value.The experimental results are summarized and the relationship between the response index and the three influencing factors is fitted and the function is carried out.Analysis of variance analysis,and then draw the corresponding surface diagram of each index under the interaction of each two influencing factors,synthesize the optimal value of each response index,optimize the influencing factors,and finally get the basalt fiber in the asphalt mixture In the optimum amount of 0.34%,the optimum length of the fiber is 6 mm,and the optimum pitch ratio is 6.6.Finally,the optimized design of the basalt fiber asphalt mixture and the actual engineering of the lignin fiber asphalt mixture were used for rutting test,low temperature indirect tensile test,immersion Marshall test and freeze-thaw splitting test,the results show that the basalt fiber asphalt mixture Material in the high temperature stability,water stability,low temperature crack resistance are better than wood fiber asphalt mixture,which in the low temperature crack resistance is particularly prominent,increased by 50.5%.The microcracking analysis of the two kinds of asphalt specimen was carried out,which provided the theoretical basis for the effectiveness of the basalt fiber in the asphalt mixture.Finally,combining with the market price of the raw asphalt mixture and the practical application of the asphalt mixture,the basalt fiber and A Comparative Analysis of the Application of Wood Fiber in SMA.