Characterization of Crushed Concrete Materials for Paving and Non-Paving Applications (7-4954-1)

This project focused on the evaluation of the feasibility of using crushed portland cement concrete (CPCC) materials in TxDOT applications. Special interest was given to the use of CPCC fines passing the No.4 sieve. The research approach for exploring potential applications was divided into two ways as follows: . paving applications: flexible base, cement treated base, and HMA bond breaker; and . non-paving applications: portland cement concrete, flowable fill, backfill, and embankment. Much of the research effort was devoted to a laboratory test program for material characterization. The test program identified aggregate properties, mix design properties, basic mechanistic properties, workability, and moisture susceptibility of the applied mixtures containing crushed concrete materials. Although the use of crushed concrete materials generally resulted in increased water demand and decreased workability, test results indicated that crushed concrete materials are highly feasible to use in the selected applications. However, CPCC fines were determined not to be suitable for the reproduction of portland cement concrete because the loss of workability was so severe in this application. Based on the results of the test program, recommendations and revised specifications, which allow for the use of CPCC fines, are provided for the selected applications: flexible base, cement treated base, HMA bond breaker, flowable fill, backfill, and roadway embankment.