Experimental Study On Deformation Performance Of Cement Stabilized Crushed Sandstone Mixture

In some area which with rich sandstone reserves,sandstone fragment usually throw in the spoil ground while building tunnels.It will protecting the environment and shorten the transportation distance to reducing material cost if make use of this sandstone fragment to build rode.In this paper,cement stabilized crushed sandstone mixture is taken as the research object.The majority of this paper is the shrinkage and Anti-Scouring performance of the mixture.Exploring the characteristics of cement stabilized crushed sandstone in shrinkage deformation.To lay a foundation for practical engineering that sandstone is used as raw material for road base and subbase.As for the mechanical properties of cement stabilized sandstone macadam mixture.This test carried out on mechanical properties of three mixtures of 3%,4%,5%cement.Including 7d unconfined compression strength.90d splitting strength and modulus of resilience.The results declare that when the cement content is 4%,the representative value of unconfined compression strength is 4.1 MPa,the splitting strength is 0.59MPa,the modulus of resilience is 1205MPa.The result of unconfined compression strength meeting the requirements of current norms with highway and the first class highway in the strength of pavement base under moderate and light traffic conditions.At first,this paper studied and analyzed the three cement dosage of 3%,4%,5%cement stabilized sand gravel mixture contraction,cement dosage improve per 1%,mixture average dry shrinkage coefficient increased by 6%,dry shrinkage strain increase 18%,temperature shrinkage coefficient increases 5%～9%.Then analyzed the three kinds of suspended solid,skeleton dense,skeleton gap is not at the same level with the mixture of shrinkage,it is concluded that the smaller the particle size of aggregate,the bigger the specific surface area,shrinkage,the more obvious,Their ratio is 1.24:1.14:1,the cumulative water loss rate and cumulative and mixture basic dry shrinkage strain was positively related to relationship.Analyses the keeping in good health again 3d,5d,7d dry shrinkage performance of mixture specimen,concluded that maintained the 3d mixture of maximum dry shrinkage coefficient is 1.8 times that of curing 7d,curing time,mixture with low tensile strength,maximum dry shrinkage coefficient is big,easy to focus craze.Finally in contrast test,4%cement stabilized sand gravel mixture of accumulative dry shrinkage strain is greater than 4%cement stabilized limestone gravel mixture 13%,temperature shrinkage coefficient is larger than water stable limestone gravel mixture about 2.85 × 10-6.In consideration of the anti scour performance of cement stabilized sandstone macadam mixture,the test inclusion 4 aspects:anti scour of conventional specimen,anti scouring of freeze-thaw cycle specimen,anti scour of dehiscence and cracking specimen.anti scour of frozen thawing deformation specimen.The result shows that the Scour quantity of conventional sandstone mixture is larger than that of limestone gravel mixture.After circulating freezing and thawing,the amount of cement stabilized sandstone mixture is less than that of cement stabilized limestone mixture After Dehiscence and cracking,the erosion volume of cement stabilized sandstone mixture increased by 0.25%compared with that of conventional specimens.The destruction strength of deformed freeze-thaw sandstone macadam mixture is the largest,its mass loss is 0.36%larger than that of the conventional test.In order to improve the shrinkage deformation properties of cement stabilized sandstone and gravel mixture,this paper puts forward some suggestions on concrete construction such as cement content,gradation,maintenance time.