J. Wei
University of Massachusetts Lowell,
United States
Keywords: Sustainable Concrete, Calcined Clay Nanoparticles, Lithium
Summary:
When considering sustainability and service-life extension, it is critical to reduce the use of cement in concrete and ensure that the structural concrete has enough degradation resistance and can still safely perform its function even in the presence of potential degradation. Alkali-silica reaction (ASR) is one of the major degradation mechanisms of concrete causing irreparable volume expansion, cracking in both aggregates and the hydrated cement matrix and substantial damages in concrete structures and hence resulting in significant maintenance costs. While prior efforts have investigated ASR suppression, a cost-effective and robust ASR mitigating approach without the deleterious effect on cement hydration and concrete properties has remained the critical challenge for many years. The present work will focus on a fundamental understanding of ASR initiation and kinetics in concrete and an approach based on cement substitution with coupled pre-saturated calcined clay nanoparticles and lithium that can simultaneously suppress multiple prerequisites of ASR accompanied with enhanced hydration of cement.