S.M Tavahhodi - Msc student, Dept of civil Engg.Tarbiat Modares University, Tehran
A.A Tasnimi - Professor, School of Engg. Tarbiat Modares University, Tehran,
A Yaghoubifar - Phd student, Dept of civil Engg.Tarbiat Modares University, Tehran

Concrete is one of the most important materials used in many types of construction. This material is widely used in seismic rehabilitation of buildings, particularly in strengthening of masonry buildings. The latter covers a wide range of historical to conventional brick buildings which are the most vulnerable in the earthquake prone areas. One of the most available, economical and simple conventional techniques used in strengthening of brick buildings is 3 to 5 mm thick concrete overlay (shotcrete) with steel mesh on the brick wall surfaces. This method of strengthening improves the seismic behavior and lateral and in-plane strength of brick walls which depends on the thickness, strength of concrete and the amount of reinforcement. In this paper, the effect of shotcrete on strength and stiffness of brick walls has been investigated utilizing micro-modeling through ABAQUS software based on discrete elements method. Results of numerical and an experimental analysis of the in-plane shear behavior of strengthened brick walls are compared and discussed. The main variables considered in this investigation are the compressive axial load applied on the wall as well as the reinforcement ratio.

RC overlay, strengthening, brick walls, discrete element