Abstract
Alkali-Silica Reaction (ASR) is a reaction that occurs over time in concrete between alkaline cement paste and reactive, non-crystalline silica in aggregates. An expansive gel is formed within the aggregates which results in micro-cracks in aggregates and adjacent cement paste. The reaction requires the presence of water and has been predominantly detected in groundwater-impacted portions of below grade structures, with limited impact to exterior surfaces in above grade structures. ASR can potentially affect concrete properties and performance characteristics such as compressive strength, modulus of elasticity, shear strength, and tensile strength. Since ASR degradation often takes significant amounts of time, developing ASR detection techniques is important to the sustainability and extended operation lifetimes of nuclear power plants (NPPs). The University of Tennessee, Knoxville (UTK) in collaboration with Oak Ridge National Laboratory (ORNL) designed and built an experiment representative of typical NPP structures to study ASR in thick concrete structures.
