Performance of D-Regions Affected by Alkali-Silica Reaction: Experimental and Analytical Study

This paper describes the experimental performance of D-region reinforced concrete bent specimens affected by varying levels of alkali-silica reaction (ASR) from none to mid-to-late stages, as determined from petrography analysis and from the presence and extent of concrete expansion and cracking. It also describes the analytical methodology employed. It is shown that specimens showing varying degrees of ASR compared with the control specimen without ASR had slightly greater stiffness, strength, and ductility, with no evident detrimental effects on structural response. The apparent improved behavior can be explained as a result of the activation of the specimen's reinforcing steel due to concrete expansion primarily from ASR, which effectively prestresses and confines the core concrete. Analytically, conventional code-based methods, including sectional analysis and strut-and-tie modeling (STM), underestimate the strength capacity of the specimens when tested to failure. (C) 2017 American Society of Civil Engineers.