Mix Design of Cement-Stabilized Recycled Aggregate Base Course Material

Abstract

Cement-stabilized recycled aggregate base course material was prepared with lower quantities of ordinary Portland cement (only 4% and 5% by weight) and recycled aggregate replacing 30%,40%,50%,60%,75%,80%,90% and 100% of crushed stone. Compaction, un-confined compressive strength and dry shrinkage of mixture were tested. The effects of recycled aggregate replacing levels and cement dosage were analyzed based on compaction test. The results showed that the use of 100% recycled concrete aggregates increased the optimum moisture content and decreased the maximum dry density of base course materials compared to those of natural base materials. The effect of recycled aggregate replacement on un-confined compressive strength was discussed at 7, 28 and 90 days. The relational model between recycled aggregate replacement and un-confined compressive strength were established. The results of dry shrinkage tests showed that the ratio of dry shrinkage of the base materials prepared with recycled concrete aggregates increased with the increase of replacement levels of recycled concrete aggregates. The primary mix proportion parameters were determined with maximum replacement of recycled aggregates, meeting the requirements of base course road performance and lower costs.