Anisotropic expansion behavior and crack orientation of reinforced concrete due to the alkali–silica reaction

Abstract

In this study, the expansion behavior, surface and internal crack developments due to the alkali–silica reaction in two types of reinforced concrete prisms with and without stirrups are investigated. Longitudinal and transverse expansions are continuously monitored at various positions on the prism surfaces. Image analysis is employed to determine the densities of surface and internal cracks. Crack orientations for several groups of crack angles are measured to characterize the dominant crack pattern. The findings indicate that longitudinal expansion was transferred to the transverse direction at the middle region in both prisms, regardless of the presence of stirrups. However, average longitudinal, transverse, and volumetric expansions are reduced in prisms with stirrups. The anisotropy coefficient of expansion exhibits a strong proportional relationship with the surface and internal crack densities of each crack angle group. Therefore, the trend of internal crack orientations and expansion anisotropy can be estimated based on surface crack information.