Simulation of Alkali-Silica Reaction Model in a Concrete Gravity Dam at the Macroscale and Mesoscale

Alkali-silica reaction causes major problems in concrete structures due to the rapidity of its deformation. Factors that affect ASR include the alkali and silica content, relative humidity, temperature and porosity of the concrete, making the relationship a complex phenomenon to be understood. In investigating the mechanical deformation of the structure, the theory of continuum damage mechanics proves to be a suitable method. Damage mechanics can be used to predict the physical and chemical behavior of a structure, making it an appropriate method to study the behavior of the structure under the influence of alkali-silica reactivity. Therefore solution of the damage model is critically needed to overcome the concrete deformation problem. In this research, an engineering example of a thermo-chemo-hygro-mechanical model of a concrete gravity dam at the macroscale and coupled with the mesoscale will be studied for varying environmental conditions of temperature and relative humidity. The simulation was developed using the stochastic finite element software. Investigations found that temperature, as well as relative humidity influences the latency and characteristic time constants, which dictate the rapidity of ASR expansion into the structure, rendering heterogeneous values across the cross-section of the structure according to the relative humidity and temperature distribution.