Research On The Road Performance Of Crack-Resistant Embedded Modified Rubber Powder Cement Stabilized Gravel Mixture

China produces a huge amount of waste tires(containing rubber powder)every year,adding rubber powder in cement stabilized gravel,using the high elasticity of rubber powder to solve the problem of easy shrinkage and cracking of cement stabilized gravel,not only can effectively prevent and control the reflection cracks on the road surface,but also can recycle resources,but because rubber powder and cement stabilized gravel are classified as organic/inorganic materials,if the two are simply mixed,it is very easy to cause rubber powder and However,since rubber powder and cement stabilized gravel are organic/inorganic materials,if the two are simply mixed,it is very easy to cause scientific problems such as the adhesion between rubber powder and cement stone interface is not dense,which leads to the decrease of material mechanical properties and loses the value of waste recycling.Firstly,this paper uses KH-550 silane coupling agent to activate and modify the rubber powder,and then applies the modified rubber powder to cement stabilized gravel,and designs a crack-resistant embedded rubber powder cement stabilized gravel mixture based on the principle of embedding and crowding and the theory of dense particle accumulation.By comparing the similarities and differences between different anti-cracking cement stabilized gravel mixture and the grade requirements of the line standard,the anti-cracking embedded grade with 4.75 mm as the key sieve hole and 30% passing rate is proposed;by comparing the effects of different rubber powder mixing order and different molding methods on the performance of the mix,it is determined that the rubber powder and cement are mixed at the same time by static pressure method,the cement dose is 5%,the rubber powder particle size is60 mesh,and the rubber powder particle size is 60 mesh.The preparation process of cement stabilized crushed stone was determined by comparing different rubber powder mixing order and different molding methods on the performance of the mix.Secondly,the road performance of four types of rubber stabilized aggregates: ordinary grade,anti-cracking grade,anti-cracking grade + unmodified rubber powder and anti-cracking grade + modified rubber powder was compared and analyzed,and it was found that the mechanical properties of rubber stabilized aggregates decreased before and after the addition of the modified rubber powder,and the dry and temperature shrinkage coefficients were significantly reduced.At the same time,the anti-cracking embedded grade has a significant effect on the performance of the mix,can meet the mechanical properties of the premise,significantly improve the shrinkage resistance of the mix.Among them,the best performance of anti-cracking embedded grade + modified rubber powder cement stabilized gravel mixture,in mechanical properties and shrinkage resistance are stronger than the ordinary grade + no rubber powder cement stabilized gravel mixture.Finally,the mechanism of the effect of modified rubber powder on the performance of cement stabilized aggregates was investigated from the microscopic perspectives of morphology,width,hardness,modulus and elements of the transition zone of the interface between rubber powder and cement stone before and after modification,and it was found that the mixing of rubber powder into the mixture reduced the water-cement ratio where the rubber powder was located,hindered the hydration process of the cement stone around it,and made the transition zone of the interface between rubber powder and cement stone a weak part.By modifying the rubber powder,the width of the transition zone between the rubber powder and the cement stone interface is obviously reduced,which makes the cement stone and the rubber powder combine more closely and improves the road performance of the mixture.The anti-cracking embedded rubber powder cement-stabilized gravel mixture designed in this paper was optimized by the preparation process and material composition to improve the anti-cracking performance of the material on the basis of good mechanical properties.Later,the mechanism of the effect of rubber powder on cement stabilized aggregates before and after modification is explained through macro and micro performance tests,which lays the foundation for eliminating the negative effect of rubber powder on cement stabilized aggregates from the root and maximizing the anti-cracking performance of the mixture.