New Technology-Based Approach to Advance Higher Volume Fly Ash Concrete with Acceptable Performance
This research project is undertaken with the National Ready Mix Concrete Association (NRMCA) and concrete experts in maturity. It suggests novel science-based approaches to address the slower rate of strength gain and delayed setting times of HVFA concrete. This project will address the two major stumbling blocks, lower early-age strengths (less than 7 days) and delayed initial setting times, which prevent the large scale utilization of HVFA concrete. Objectives of the project are: to demonstrate by using a maturity based approach that HVFA concrete in the structure has sufficient early-age strengths to allow for optimized construction scheduling; and to demonstrate that by using some suitable chemical admixtures or additions the initial setting times of Class C fly ash concrete is not delayed. Based on these approaches a step by step procedure will be developed that the concrete producer and the construction team can adopt to manage the resulting properties of HVFA concrete during mixture development and construction scheduling. The project includes extensive filed and laboratory testing with instrumentation related to the maturity concept of concrete, and non destructive testing of concrete using the pull out method.