1) MsC Student, Federal University of São Carlos, Civil Engineering Dept,

2) PhD, Professor, Federal University of São Carlos, Civil Engineering Dept,


Present paper deals with infilled frames with masonry. The use of infill is already included in several countries codes as Canada [3], Peru [6], New Zealand [8] and United States [5]. The focus is on the behavior of multiple story reinforced concrete building frames with and without masonry infill. Numerical models were created to identify the influence of infill masonry in reinforced concrete building frame.

The inclusion of the infill masonry panel is considered in two different modelling: considering the simple equivalent diagonal bar and modeling the masonry as shell elements. About the equivalent diagonal, were considerate normative recommendations as in the New Zealand, United States and Canadian codes. The shell element was used in a finite element macro modeling, considering the infill material as small-tension masonry for simple non-linearity consideration. It was used the computer program SAP2000, version 14.

The structure of one originally 15-floors reinforced concrete building is used as study-case. The models varies on the code specifications, the number of floors, the masonry material, the presence of not of a gap in the RC beam – masonry panel interface and on the number of floors.

In conclusion, a great lateral stiffness of the structure was observed with striking reduction of horizontal displacement when considering few masonry panels in the structural model. Such contribution varies with the different options of masonry strength, of the lateral force and of number of floors.


Keywords: infill, infilled frame, bracing, stiffness, equivalent diagonal.