The Study Of Freezing And Thawing Cycle Of Lime-fly Ash Stabilized Bound Macadam Of The Cement Stabilized Crushed Stones

With Chinese rapid development of road transportation,the cement stabilized crushed stones,lime-fly ash stabilized bound macadam mixture as a semi-rigid base course material are widely used with excellent grass-roots road performance in the primary road.Climatic conditions in Heilongjiang Province are seasonal frozen area,and the minimum temperatures can reach -30℃～-40℃in winter.With the traffic loads and frozen role,when a new highway is used,the pavement structure can exist a certain degree damage.In recent years,the investigation found that the structure layer of damaged pavement,as a semi-rigid cement stabilized crushed stones,is easy to exist some situations,such as loose,crushing,lower intensity in the process of the use.Analyze the causes,in addition to roads seep water,roadbed is humid,pavement structure design and construction control exists some problems,frozen results in material strength attenuation is also a very important factor.Based on the analysis of the cement stabilized crushed stones,lime-fly ash stabilized bound macadam mixture,papers go deep into investigate the use situations of the cement stabilized crushed stones,lime-fly ash stabilized bound macadam primary levels of the road which has been built,and analyze the causes of damage and compare with the research results. Through laboratory test(using low-temperature laboratory to simulate natural environment and to carry out freezing and thawing cycles test),analyze and compare the attenuation regular pattern of the different grade of cement stabilized crushed stones,lime-fly ash stabilized bound macadam when they are frozen,in order to get grade range and the optimal mix of resistance role,and test and verify this result on test road.Under different conditions, Determined the material strength attenuation coefficient in order to provide a certain the reliability value of the design strength of cement stabilized crushed stones,lime-fly ash stabilized bound macadam under the impact of the freeze-thaw cycle at the grassroots level design.Guarantee the primary levels have certain frozen durability in the period of use so that we can improve the quality and extend the road service life,and decrease cost of maintenance and upkeep.