2018 Volume 74 Issue 2 Pages 192-201
Crushed concrete aggregate (CCA) is one of the major construction byproducts. It is currently widely recycled as a road base material but it might be also considered as a good potential fill or backfill material for typical soil structures such as embankments. To examine the above, its physical, mechanical and chemical properties were investigated by performing of a comprehensive series of laboratory tests, including compaction and consolidated-drained triaxial compression tests. Two types of CCA materials retrieved from two concrete structures of different periods were used and their grain size distribution were relevantly adjusted. CCA comprises composite particles made from cement paste, fine and course aggregates. Cement paste is responsible for solidification of particles after compaction but may also cause elution of hexavalent chromium Cr(VI). As far as mechanical properties are concerned, strength of compacted CCA was found to be equivalent to that of a natural well-graded gravelly soil. Compacted CCA with unhydrated cement particles remaining showed further increase in strength while curing, under the conditions of compaction realised in the present study.
