A comparison between numerical and analytical homogenized models for visco-elastic brickwork

The creep behaviour of periodic brickwork is dealt with. An analytical model is proposed, in which units are assumed to be either rigid or elastic and creep effects are confined to mortar joints. Closed-form expressions for the creep coefficients under elementary macroscopic stresses are obtained. A parametric study is carried out to investigate the sensitivity of the analytical creep coefficients to the material parameters. The accuracy of the theoretical predictions and the reliability of the simplifying assumptions is assessed through comparisons with the numerical results obtained discretizing any representative volume element by finite elements and taking the creep behavior of both component materials (bricks and mortar) into account. Experimental data available in the literature for calcium silicate bricks and mortar were used to calibrate the model. The analytical creep coefficients are found to be accurate as the ratio of the elastic modulus of the units to the elastic modulus of mortar is greater than 20.