Study On Crack Resistance Property About Bituminous Pavement On The Cement And Flyash Stabilized Crushed-stones Roadbase

As a new type of semi-rigid basis, the roadbase of cement and fly- ash stabilized crushed-stones has many characteristics, such as early-strengthening, high strength, less cracks and early-opening to traffic. Besides, it also grows much in post-strength and benefits in supporting the increasing transportation, especially to the overloading transportation. Unfortunately, there is no concrete provision on the design and construction of the cement and fly-ash stabilized crushed-stones roadbase in present specifications. Without such instruction, design and construction departments just have to reference the gradation envelope and intensity index of the cement stabilization or lime fly-ash stabilization in practice. It is also much optionally. Besides, without suitable selection of raw material and mixture ratio design, the roadbase of cement and fly- ash stabilized crushed-stones appears less resistance to crack, to scour in resisting property and to freezing. So we need to have a system study in material, ratio, function, design, construction and cracking prevention.This topic mainly makes a system research on the bituminous pavement of cement and fly-ash stabilized crushed-stones roadbases, bringing forward two indexes. One is the cement and fly- ash stabilized crushed-stones shrinkage cracking resistance index, basing on the basis material's water content variety in construction season, shrinkage cracking resistance coefficient and strength bias factor. The other index is temperature-shrinkage cracking resistance index, basing on construction temperature, the biggest temperature difference per year and temperature-shrinkage cracking resistance coefficient. This paper carry out the following research works in details: l)the mix design methods of high-performance cement and fly- ash stabilized crushed-stones. 2)the relations as basis for pavement structure design: one between compressive strength and compression modulus of resilience in seven days, another between seven-day compressive strength and 180-day splitting strength. 3)the temperature field of the roadbase of cement and fly- ash stabilized crushed-stones in the stage of winter, with unpaved bituminous pavement . 4)The effect regulation between preformed saw, width and depth of the roadbase of cement and fly-ash stabilized crushed-stones, deducing out the Compute formula of Size parameter of saw, and Suggesting a value size of saw.