Infill brick has a vital role in the seismic performance of reinforced concrete frame buildings. But like other standards for building design, infill masonry is not considered in the assessment procedure of the Bangladesh National Building Code (BNBC). A lack of understanding as regards infill material behavior has meant that it is not considered as a structural element. It is therefore important to research the seismic performance of infilled reinforced concrete frames constructed in Bangladesh and establish the appropriate retrofit measures for both infilled frames and “soft-story” mechanisms.
This thesis focuses on the effectiveness of ferrocement jacketing on reinforced concrete frame structure with masonry infill. Ferrocement is a kinds of steel-and-mortar composite material of small thickness, about 25 to 38mm. Essentially a form of reinforced concrete, it exhibits behavior so different from conventional reinforced concrete in performance, strength, and potential application that it is classed as a completely separate material. It differs from conventional reinforced concrete in that its reinforcement consists of closely spaced, multiple layers of steel mesh completely impregnated with cement mortar.
The specimens were confined by ferrocement layers all-around, this method of confinement is termed as jacketing in this paper. In addition, the effect of ferrocement jacketing on bare reinforced concrete frame, and the contribution of two types of brick infill on reinforced concrete frame during application of lateral load are also discussed.
Based on experimental results, a comparative study of the performance of different types of damaged reinforced concrete frame due to application of cyclic lateral load jacketed with ferrocement was performed. The lateral load carrying capacity, and ductility of reinforced concrete frame, with and without masonry infill also discussed in this study.
3 types of reinforced concrete frame were considered for experimentation. Type 1 was bare reinforced concrete frame, type 2 was conventional clay brick infilled reinforced concrete frame and type 3 was hollow ceramic clay block infilled reinforced concrete frame. Each type 2 specimen was tested in two phases. Firstly new specimens were subjected to cyclic lateral load until substantial damage occurred. Secondly, damaged specimens were jacketed with ferrocement and then subjected to the same loading conditions.
Both bare and infill jacketed reinforced concrete frame with ferrocement showed significant improvements in strength and ductility. This suggests the possible use of ferrocement as a retrofitting and/or strengthening material of reinforced concrete frame.
Keywords: Reinforced Concrete Frame, Cyclic Lateral Load, Ferrocement Jacketing.