Experimental collaboration for thick concrete structures with alkali-silica reaction

Abstract

Nondestructive analysis of alkali-silica reaction damage in concrete slabs using shear waves AIP Conference Proceedings 1949, 040003 (2018) 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 microcracks 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. MOTIVATION, DESIGN, AND IMPLEMENTATION

Nondestructive Evaluation of Concrete within Nuclear Applications

“…Oak Ridge National Laboratory (ORNL) has supported the NDE of concrete under the Light Water Reactor Sustainability (LWRS) program [1][2][3][4][5][6][7]. This effort has included the development of concrete specimens to study the detection of known concrete defects, such as delamination, voids, honeycombing, and alkali-silica reaction (ASR).…”

“…The U-MBIR method requires more research to decrease the processing time from several hours to several minutes; however, a clear path for accomplishing this was identified, which included using SAFT reconstructions as a prior (i.e., image) model. Both reconstruction techniques are discussed in greater detail in multiple reports and publications [1][2][3][4][5]. Areas of collaboration were identified through the roadmap development.…”