Numerical investigation on expansive volume strain in concrete subjected to sulfate attack

In order to evaluate numerically the volumetric expansion of concrete under sulfate attack, models are proposed to calculate the expansive volume strain of concrete exposed to sulfate solutions. Firstly, a one-dimensional differential equation related to the diffusion–reaction behavior of sulfate ions in concrete is presented; secondly, based on chemical reactions between sulfate and calcium aluminates in concrete, the expansive volume strain caused by ettringite growth is obtained; thirdly, numerical analysis is carried out to investigate the volume expansion of concrete when it is exposed in sulfate solutions. Numerical results provide the evolution response of concrete volume expansion with the diffusion time, sulfate concentration, and calcium aluminates dissipation.

► Models of diffusion and reaction behavior of sulfate ions in concrete were proposed.
► Expansive volume strain was obtained due to ettringite growth.
► Time-dependent process of concrete expansive volume strain was investigated numerically.