Application of Concrete Maturity in Evaluation of Rapid Hardening Portland Cement Concrete

The primary objective of this research was to study the feasibility of using concrete maturity concept as a quality-control and quality-assurance tool to predict compressive strength of high-early strength (HES) concretes for use in rapid repairs of concrete pavements and bridges. In this investigation, the Temperature-Time Factor (TTF) method based on the Nurse-Saul equation was used to predict the concrete strength. To study the validity of the maturity concept at different seasonal temperatures that are typical to South Carolina, maturity parameters for the HES concretes were developed using different isothermal curing environments, and subsequently correlations between strength properties and maturity were evaluated. Results from this study indicate that HES concretes for use in rapid repairs of concrete pavements and bridges can be produced with local materials. Maturity concept can be applied with good reliability in predicting the strength of HES concretes, when the maturity of concrete is less than 500 degrees Fahrenheit/hours and by using maturity at final setting as zero reading. Based on the findings from this study, it is concluded that concrete maturity technique can be employed as a viable tool to assess quality control and quality assurance in fast-track construction projects,provided adequate attention is provided in developing the underlying maturity parameters. As a next phase to this research study, it is recommended that a field validation of concrete maturity for use with rapid-repair concrete and conventional pavement concrete be conducted and a concrete maturity protocol be developed to allow for the use of this technique for routine quality assurance and quality control practices.