National Concrete Pavement Technology Center

Project description

The use of fly ash in concrete has become a common practice in the US. On the other hand, fly ash has been also used as a key ingredient for geopolymers recently introduced as an ecofriendly and sustainable alternative to ordinary Portland cement (OPC) in concrete. However, the decline in coal-fired power generation and stricter environmental regulations have led to a scarcity of high-quality fly ash in the US and consequently an increase in its price. Calcined clays (CCs) are a promising alternative to fly ash due to their wide local availability. They are rich sources of alumino-silicate species needed for both pozzolanic reaction that takes during the curing of OPC and the geopolymerization reaction. Preliminary results from a previously funded Tran-SET project (20CLSU07) show that several readily available CCs in Region 6 are potentially useful as SCMs in concrete. While preliminary results are promising, further characterization of the CCs and their comprehensive evaluation in concrete is required to develop the necessary engineering knowledge for their use in the field. As a response to the expected shortage of fly ash, the main objective of this project is to evaluate calcined clays (CCs) as a much-needed alternative source for the future of concrete materials for the transportation infrastructure in Region 6. Going beyond the use of CCs as alternative SCMs, the present projects also aims to evaluate the feasibility of using CCs as a precursor for the synthesis of geopolymer binders, which could be used for the production of cost-effective and environmentally friendly geopolymer concrete for the transportation infrastructure in Region 6.