Finite element model application to flexural behavior of cement stabilized soil block masonry

Abstract

A finite element model for cement-stabilized soil block (CSSB) masonry members—including nonlinear stress-strain relationship—has been developed and compared with experimental results. Primarily, this model serves as a simulation tool to study various problems for a large number of stress–strain state and loading conditions of CSSB masonry elements. The model presented is characterized by several parameters experimentally ascertained through triaxial and other testing. Furthermore, these parameters allow the model to capture the elastic, plastic, and softening behavior of CSSB masonry. From a constitutive behavioral standpoint, at small strain levels, the material is approximated as linear elastic. Plastic deformation of the material is captured with a modified version of the Sandia Geomodel, which is specifically designed to replicate geological material behavior. Lastly, at localized softening failure, a damage-like constitutive model which takes into account the normal and shear traction balance on the slip-weakening surface is employed. This model includes cohesion degradation as well as friction under compression. Within the finite element framework, the Strong Discontinuity Approach is used to track localized material failure from element to element. In addition to this, a novel method for modeling interfaces in finite elements is used to replicate the behavior of brick-mortar interfaces. The two featured experiments which are simulated in this study are normal to bedjoint and parallel to bedjoint masonry setups, simplified via a plane strain approximation.