Zihui Li, Robert J. Thomas, Diego Lazama, Sulapha Peethamparon
Alkali silica reactions, Compressive strength, concrete, Cracking, Durability, Fly ash, Portland cement concrete, Shrinkage
Increased awareness in this decade on the significance of developing sustainable materials for construction has renewed the interest in exploring Alkali Activated Concrete (AAC), a concrete that contains no cement but only industrial by-products such as fly ash and slag, as a low energy alternative to the conventional concrete. Preliminary studies to evaluate the potential of alkali activated slag/fly ash as a sustainable alternative to Portland cement concrete is quite promising. Strength comparable to Portland cement concrete has been obtained in AAC under laboratory conditions. Through a UTRC2 grant, principal investigator's (PIÛªs) research group has successfully developed AAC with compressive strengths as high as 60 MPa using slag or class C fly ash as the sole binder, and sodium silicate solution as the activator. However, transfer of this technology to the field has not received the expected momentum, primarily due to two major technical concerns: (1) potential for higher shrinkage and increased cracking, and (2) uncertainty associated with the possible Alkali Silica Reaction (ASR) related durability issues. Conducting experimental studies focusing on the detailed assessments of the durability performance is the most powerful mean to overcome these barriers.