Identification of Compliance Testing Method for Curing Effectiveness

15. Supplementary Notes Project performed in cooperation with the Texas Department of Transportation and the Federal Highway Administration. 16. Abstract Curing has substantial effects on the long-term performance of Portland cement concrete (PCC) pavement. TxDOT requires two applications of curing compounds, with a maximum 180 sf/gal per each application. However, no compliance testing is conducted for curing and, from a practical standpoint, compliance with specification requirements are rarely verified. The purpose of this research was to identify simple testing procedures that can be implemented to verify the compliance with specification requirements on curing. To this end, various test methods that appear to have potential for compliance testing for curing were evaluated in the field. The test methods evaluated include penetration resistance, initial surface adsorption, surface temperature, reflectance, relative humidity, and dielectric constant. A factorial experiment was set up for field testing, and the test methods were evaluated in the field. Varying rate of curing compound applications as well as application time was included as variables in the factorial experiment. Advantages and limitations of each method were identified and discussed. Based on the findings, it is concluded that the methods evaluated are neither practical nor accurate enough to be included in TxDOT specifications as a compliance testing. Rather, it appears that evaluating curing compound application rates by measuring curing cart speed could present most feasible method for compliance testing.