Overall assessment of CFRP-wrapped concrete affected by alkali-silica reaction

Abstract

The multi-level approach coupling of mechanical (i.e., Stiffness Damage Test -SDT) and microscopic (i.e., Damage Rating Index -DRI) testing procedures, was found to be promising for evaluating the condition of ASR-affected concrete elements under unconfined and internally confined conditions. Yet, only a few studies investigated the effect of external confinement (i.e., CFRP wrap) on ASR-induced damage. Thus, this study aims to study the impact of various external confinement conditions (i.e., none, 1 ply CFRP and 2 plies CFRP) on ASR-induced damage. One hundred and seventy concrete specimens incorporating distinct reactive aggregates (coarse and fine aggregate) and confinement conditions were fabricated, stored in an environmental chamber, and monitored over time. Upon reaching the given expansion levels, a multi-level assessment was conducted. The results show the mitigation nature of confinement against ASR-induced expansion as well as yielding damage transfer according to the confinement condition. Moreover, different crack features and orientations, as well as mechanical degradation, are observed in restrained specimens, which confirms that ASR exhibits different damage developments under “free expansion” and externally restrained conditions.