MECHANICAL PROPERTIES OF CEMENT STABILIZED MIXTURES OF RECYCLED ASPHALT AND CEMENT CONCRETE FOR USE IN PAVEMENT

One of the major problems caused by construction and demolition of buildings and highways is the environmental pollution due to the disposal of the huge amounts of produced waste materials. Therefore, in addition to the protection of environment, the recycling and reusing of the waste materials is an economical measure. One of the applications of the waste materials is for highway construction. In order to investigate the viability of using the waste materials in pavement structure, as cement stabilized base or sub-base layer, in this research, some physical and mechanical properties of the recycled asphalt and cement concrete stabilized by cement and reinforced by steel fibers have been studied. The recycled asphalt and cement concrete were mixed in 5 different proportions, and stabilized by different cement and steel fiber contents. The compaction properties and the compressive and bending strength of the mixtures have been investigated. The results show that, in all combinations, the optimum moisture content and the maximum dry density increase with increasing the cement content. In addition, it is found that, up to 9% of cement content, the compressive strength increases with increasing the cement content, and beyond that, the compressive strength decreases with increasing the cement content. Also, the compressive strength of the mixtures increases by addition of steel fiber, with the highest compressive strength at 1% of fiber content. The results also show that, the bending strength of the mixtures increases by increasing the cement and steel fiber content. A linear relation is found between the bending and compressive strength of the mixtures. It is also shown that the cement stabilized mixtures are more economical than the traditional unbound natural aggregates for using in base and sub-base layers.

کلیدواژه ها:

recycled concrete ، recycled asphalt ، cement stabilization ، steel fiber