The Research On Stiffness Control Index Of Cement Stabilized Gravel Layer

Semi-rigid base due to its low construction cost, with high stiffness and loaddiffusion capacity, good water stability characteristics, has been a very wide range ofapplications in highway construction in China. The modulus and strength ofsemi-rigid base material are changing with the increase of age, varying the flexure ofthe top of surface. Semi-rigid base asphalt road surface are more sensitive to the axleroad when the vehicles overload. Under the same overloaded vehicles, it is affectedmuch more compared to the flexible base asphalt road surface, casing much moredamages to the surface. If the carrying capacity of the semi-rigid base can’t meet therequirement, it’s necessary to explore the stiffness index of modules of resilience andflexure of resilience in structural layer of cement stabilized gravel.It analyses the strength and other sides commencing from the structural layermaterial of cement stabilized gravel, based the Ningdao highway project. And then,on one side, it conducts the theoretical calculations in modules of resilience andflexure of the structural layer through BISAR. One the other side, it spot test theflexure and modules of resilience through Beckman beam and loading plate, analyzingthe changing rules of the modules of resilience and flexure of structural layer indifferent age. It find that the modules of resilience increases in the mass and come to astable number by cutting down the raising trend. And it also find that the modules ofresilience is cutting down step by step. To sub-base and base of the cement stabilizedgravel, it find the modules of resilience in sub-base is smaller than that in base.Because there are more coarse aggregates in base than those in sub-base, and thehigher inner frictional resistance decide the higher strength. Put forward the flexuremultiple correction factor by analyzing the calculation index and test index. Afteranalyzing the water-stable structural layer theoretical and testing stiffness index,combining indoor and outdoor test, find out the influencing factor, and put forwardthe requirement to the construction quality control to reach the highway servicinggrade.