Performance and Utilization of Recycled Aggregates for Airport Cement Concrete Pavement

Abstract

Cement concrete of airport pavement can be crushed into aggregates for recycle using, and the performance and utilizations of the recycled aggregates were discussed and researched herein. Sieve analysis indicated that the concrete should be crushed many times till the percentage of critical size (31.5mm) can satisfy the gradation requirements. Due to loss of crystal water, the density and water absorption of recycled aggregates were different from the natural ones, so that an empirical corretion equation was addressed subsequently. When the recycled aggregates used in the stablized base, theres no avilable method could yield the optimum water content, therefore a series of compaction and compression tests were employed to set up a modified design method. The results indicated the shrinkage property of recycled aggregates were susceptible to the moisture, either the skeleton-dense material structure and limiting the fine aggregates content were possible ways to eliminate the sensitivity. 7-day unconfined compressive strength results proved the recycled aggregates were suitble for the base course of heavy duty highways and airfield in grade E/F as well.