Research On The Preparation And Performance Of Granite Asphalt-Treated Base

In recent years, our country's construction of asphalt pavement highway is developed rapidly. With the increasing service life, the pre-damage of the asphalt pavement has become more and more serious. One of the effective ways to deal with the pre-damage is the application of the asphalt-treated base, which cut down the amount of reflective cracks as result of shrinkage cracking base, and have self-healing property. In addition, the material structure of pavement is similar so that the force and deformation of asphalt pavement are more coordination. Thirdly, the stiffness of asphalt-treated base is small and the probability of cracking is reduced. China has massive land and complex geological structure, the acid aggregate is rich in some places where the calcareous rock or neutral rock is lacked. Therefore, it is necessary that the balance of the cost of construction and performance is taken into account when choosing resources of aggregate. According to those two reasons, the application of granite in asphalt-treated base which can reduce the cost of construction and make use of the resources in an integrated manner, is analyzed in this paper.The rheological property of asphalt binder with granite powders was studied by dynamic shear rheology after granite powder, which respectively mixed with cement, hydrate lime and activative mineral, was added into asphalt. The results show that the composite shear modulus of granite-asphalt binder with modifier is more than without modifier, increases the rutting factor of granite-asphalt binder and improves the resistance to permanent deformation.By the conventional experimental methods, the road performance was tested. The results show that the granite asphalt-treated base have excellent Marshall stability and capacity that resists the deformation, meantime the residual Marshall stability and freeze-thaw split ratio of granite asphalt mixture are improved significantly and the performance of resistance water damage is also enhanced.Based on the above research, three-point bending test, creep test and four-point fatigue test were carried out in this paper so that the performance of granite asphalt mixture that mixed with cement, hydrate lime and activative mineral, was described. The results show that the granite asphalt-treated base mixture which is modified have certain ability to delay the crack propagation, and can settle with the problem of cracking asphalt pavement, and the resistance to permanent deformation of modified granite asphalt-treated base mixture at high temperature is improved by the addition of granite powder, therefore the rut and other damage of asphalt pavement are delayed. Longer service life of asphalt mixture under the same strain level, and more excellent fatigue-resistance can be obtained as the asphalt mixture is modified.