Finite element analysis of masonry infill panels retrofitted with ferrocement

Abstract

Retrofitting of damaged masonry infilled frame using ferrocement overlay as well as strengthening of existing infilled frames with ferrocement is a cost effective method in the context of Bangladesh, where many old structures need such retrofitting or strengthening works against possible earthquake hazards. However, virtually no mathematical or computational information is available to quantitatively estimate the effect of such retrofitting technique. The study presents a numerical investigation of the retrofitting effect of masonry-infilled reinforced concrete frames by ferrocement. The finite element technique has been effectively used to analyze bare RC frames, unretrofitted masonry-infilled and retrofitted masonry-infilled frames. The proposed model accommodates the material nonlinearities of both concrete and masonry, and yielding of reinforcing bars. The FE analyses procedure used in this study has been able to simulate test results on infilled RC frames verifying the effectiveness of such FE modeling. The same FE model was then used to simulate the test results of a retrofitted RC frame. It has been found that the lateral load carrying capacity of the damaged and retrofitted frame predicted by the FE model is in close agreement with the experimental results. The FE analysis methodology has been proven to be an effective tool to reasonably estimate the load carrying capacity of the retrofitted infilled frames without resorting to expensive laboratory testing. This approach can now be effectively used 111 predicting the existing capacity of the building frames as well as the degree of strengthening that would be required to achieve if ferrocement overlay is applied as a retrofitting material.