Improved infill walls and rehabilitation of existing low-rise buildings

Five to 10% of buildings in earthquake prone areas, with structural deficiencies and non-structural partitioning walls are expected to collapse totally during a severe earthquake. Relying on the encouraging early test results, transforming a selected number of non-structural partitioning walls to structural walls has been considered as one of the realistic preventive measures if sufficient reliability is achieved both experimentally and theoretically. The major part of the recent experimental and theoretical works of The Structural and Earthquake Engineering Laboratory of Istanbul Technical University (ITU) has been devoted to achieve better understanding of the seismic behavior of brittle partitioning walls which are generally ignored in the design, rehabilitation design or evaluation stages of ordinary low-cost, lowrise, reinforced concrete relatively old buildings. In this chapter the complementary tests and analytical works carried out for this purpose are summarized to come up with a cost-effective prescriptive solution to prevent the total collapse of buildings. The proposed retrofitting technique is exemplified through the mathematical models of strengthened buildings offered by codes which are reviewed as well. The experimentally developed data such as the modulus of elasticity of clay brick walls, damping ratios, shear strength of improved partitioning walls and earthquake load reduction factors are referred in the analyses.