Study On Mechanical Properties Of Recycled Materials As Railway Ballast And Subballast

As a traditional type of railway system,ballast track has the advantages of convenient maintenance and low cost.However,the continuous increase in the speed of the railway has caused the deterioration of the ballast which has caused changes in the geometry of the track and caused high maintenance costs for the ballast track.At the same time,the railway network continues to expand,and the shortage of natural rock resources has caused the high cost of ballast track,which reducing its advantage over slab track.Therefore,the discovery of new ballast crushed stone(ballast / subballast)is of great significance for saving railway costs.Steel slag has been proved to be a recycled material that can be used in the construction field,and studies have shown that it can be used in ballast layers,and it provides a new alternative idea for the shortage of railway stone resources.The research surface shows that waste tire rubber materials have been used in railway sleepers and ballast elastic aggregates in foreign studies,the results show that its application in railway can delay the deterioration of the ballast and provide elasticity.After the concrete and waste bricks in urban construction waste are broken and recycled,It has been proved to have good mechanical properties and has application prospects in railway graded crushed stone.In this paper,for the recycling of solid waste recycling materials,a series of mechanical tests(Los Angeles abrasion test,direct shear test,Static stiffness test,monomer crushing test)are carried out on steel slag,steel slag-ballast mixture,Neoballast,recycled concrete aggregate,recycled brick slag to analyze the applicability of solid waste recycling materials in railway graded crushed stone(ballast / bottom ballast).The conclusion is as follows:(1)The mechanical properties of ballast of steel slag are general,and the deterioration resistance and shear resistance of the steel ballast are significantly lower than that of the super ballast;the deterioration resistance and shear resistance of the steel slag-ballast mixture are more obvious than that of pure steel slag Promote.The steel slag mixing ratio is controlled at 50% or less,which can ensure that the steel slag-ballast mixture meets the super ballast standard in terms of wear resistance,and its shear strength is only 8.5% lower than that of the bit ballast.The stiffness of the ballast bulk;in the areas with large steel production in the north and middle east of China,the steel slag railway reuse method can reduce the track bed settlement,at the same time save ore resources and effectively dispose of waste;(2)Rubber particles as elastic aggregates incorporated into ballast can effectively delay the degradation of ballast.As the particle size of rubber particles decreases and the volume ratio increases,the effect of delaying the degradation of ballast is more obvious,and it is more effective for small particles.The diameter and low-grade ballast particles are better;after the waste tire rubber particles are bonded,the anti-degradation characteristics of the rubber particle-adhesive ballast are improved by about 60%,but the shear strength is lower than that of the super ballast.Settling occurs,and the 0.0-0.25 mm rubber particle adhesive ballast ballast has better resistance to deterioration and shear resistance than the 2.5-5mm rubber particle-adhesive ballast ballast;rubber particle-ballast ballast mixture and rubber particle-adhesive ballast ballast Can be used on rigid foundations such as stone cuts,bridges and tunnels to enhance the elasticity of the track bed;(3)The abrasion resistance of recycled concrete aggregate and steel slag is better than ordinary bottom ballast,and the abrasion resistance of brick slag is slightly weaker than the bottom ballast,but they are all within the range of the bottom ballast abrasion rate specified in the specification;On the top,recycled concrete aggregate,recycled brick slag,and steel slag are better than ordinary bottom ballast;at the same particle size,the crushing resistance of recycled concrete aggregate,recycled brick slag,and steel slag are better than ordinary bottom ballast;In areas and areas where steel mills are concentrated,the bottom ballast can be replaced with recycled concrete aggregates and steel slag to optimize the mechanical properties of the bottom ballast,and the recycled brick slag can be used on lines with a lower design speed.Based on the above conclusions,the steel slag-ballast mixture with a steel slag mass ratio of 50% or less can be used as a substitute for super ballast;neoballast can replace the part with ballast bed to achieve the effect of delaying degradation;recycled concrete aggregate,Steel slag can be used as railway bottom ballast,and brick slag can be used on lines with lower running speed.While solving solid waste materials,alleviating the shortage of natural stone resources is in line with the concept of sustainable development.