Performance and Characteristics of Recycled Concrete Aggregate as Base and Subbase Material

This research presents the test results of the laboratory and field studies that have been performed to address concerns about the use of recycled concrete aggregate (RCA) as base and subbase materials in pavement structure. Performance concerns have focused on compactability. stability shear resistance and breakage of the RCA in the laboratory using the U. S. Army Gyratory Testing Machine (GTM). The tests conducted both in dry and wet conditions. The tests results showed that the RCA performed much better than the gravel in both conditions and equal to the crushed stone aggregate. A field study conducted the vicinity of Indianapolis. where the I-70 freeway connects the Indiana state with the Ohio state. The RCA was used as base and subbase materials for concrete pavement. The length of demonstration pavement was approximately 10 Km. The falling weight deflectometer (FWD) was used to measure the deflection of the pavement both of the RCA and crushed stone aggregate section. The radius of relative stiffness (lk) showed that the RCA is capable of resisting the traffic load and showing the long-term stability.