A two-phase model for chemo-damage induced anisotropy in concrete

Chemical reactions, supported by temperature variations, may produce growing damage in existing concrete structures. With specific reference to the expanding gel produced by the alkali-aggregate-reaction, occurring in many ageing concrete structures such as concrete dams and reinforced concrete bridges, an anisotropic bi-phase coupled chemo-thermo-mechanical anisotropic damage model is proposed, capable to account for the macroscopic strength and stiffness deterioration in the concrete skeleton due to the expanding gel. The model is validated against experimental tests taken from the literature.