Study On The Road Performance Of Basalt-polypropylene Hybrid Cement Stabilized Gravel

Cement stabilized macadam is one of the most common pavement base structure,however,often appear crack on the base of the cement stable macadam mixture,water damage and other diseases,reduce the service life of pavement,increase the cost of road maintenance and repair.In recent years,it has become a hot research direction to apply fiber to cement stabilized gravel to improve the road performance of cement stabilized gravel.Properties of different fibers have different,its elastic modulus,density,toughness,length,diameter,water unambitious,and so on are different,the different properties of polyester fiber in cement stabilized macadam,for each of the cement stabilized macadam road with the improvement of performance are also different,therefore,different fiber mixed after used in the cement stabilized macadam,to play the advantages of each type of fiber,foster strengths and circumvent weaknesses,a comprehensive enhance road use performance of the cement stabilized macadam,has become a new research direction.However,it is a technical problem how to distribute the different fibers evenly to the cement stabilized gravel mixture.In addition,how will have different nature fiber combination,foster strengths and circumvent weaknesses,play to the advantages and make up for the disadvantages of each fiber,hybrid fiber in cement stabilized macadam makes out the effect of 1 + 1 is greater than 2,avoid the phenomenon of hybrid fiber road performance decline,also need a lot of test.This paper,taking as the research object,on the base of the cement stable macadam mixture in the cement stabilized gravel base hybrid fiber,mixed with a proportion of the guarantee of cement stabilized macadam base construction cost under the premise of hybrid fiber to explore the influence of cement stabilized gravel base road use performance research.This article selects the basalt fiber and polypropylene fiber,through the orthogonal experiment optimization size and content of these two kinds of fibers,after mixing to test the comprehensive strength,extramural strength test,drying shrinkage performance test,the temperature shrinkage performance test,frost resistance test,to verify that the basalt-polypropylene fiber to improve the performance of cement stabilized macadam with role.The research of this subject has important social and economic effects on reducing the occurrence of primary diseases of cement stabilized gravel,ensuring the life of the road and the capacity of transportation,and saving maintenance and maintenance funds.The results show that the hybrid fiber on the mechanical property of cement stabilized macadam road-base,durability,shrinkage performance and extend the service life of road surface has the very good effect.By basalt fiber and polypropylene fiber size and content selection,determine the length of the basalt fiber is 25 mm,the optimal dosage of 0.08%,the length of the polypropylene fiber for 19 mm,best dosage is 0.04%;Under the influence of the dosage of hybrid fiber,hybrid fiber 14 d compressible strength of the cement stabilized macadam can be increased by 10.35%,14 d bending tensile strength increased by 28.57%,28 d dry shrinkage coefficient was reduced by 36%,28 d temperature shrinkage coefficient reduced by 13.27%,freeze-thaw splitting strength ratio increased by 14.16%.This topic research of hybrid fiber was applied to cement stabilized gravel base and semi-rigid base in the pavement engineering of the popularization and application has a certain reference significance.