Experimental and Analytical Analysis of RC Frames Strengthened Using RC External Shear Walls

In this study, we have investigated the application of an external RC shear wall as a method of improving the performance of reinforced concrete (RC) frames in an earthquake. We produced a series of eight RC frames, each of which was modeled at a 1/3 scale with two floors and two spans. These frames were of the same size and had design and construction deficiencies commonly encountered in the RC buildings in Turkey. We tested four of the eight frames without any strengthening, under reversed cyclic lateral loadings resembling earthquake loads. The remaining four frames we tested under the same conditions after strengthening them with RC external shear walls. We arranged the axial force loads applied to the columns of the test models in two different ways to result in tensile and compression failure. The test results were analyzed on the basis of a comparison using static push over analysis. The results of the experimental tests and analytical studies showed that the RC external shear wall improved the seismic character of the existing RC frame as much as RC infill walls, therefore this method can be used as an alternative strengthening method. Also, the method provides effective, practical and economical strengthening that minimizes the need for additional works and does not restrict the use of the RC building.