Lateral load analysis of Retrofitted Masonry wall using Steel strips and Poly Propylene fiber

Abstract

Masonry is widely used type of construction in the world. But these walls are built with no seismic loading requirements and they are not capable of dissipating energy through inelastic deformation during earthquake. Recent earthquakes have shown that many such buildings are seismically vulnerable and should be considered for retrofitting. To prove the efficiency of retrofitting of masonry structures, this thesis deals with an Experimental programme to ascertain the compressive and shear strength enhancement of masonry wall panels using steel strips and polypropylene fibre. The study includes six wall panels, three each for compressive and shear strength evaluation. In each of three walls, one wall is unreinforced masonry wall, the second is reinforced on both sides with diagonal steel strips and the third is reinforced with closely spaced polypropylene mesh. Separate testing arrangements we made for compressive and shear strength tests. During compressive testing only vertical load is applied and for shear strength determination, lateral load with vertical pre-compression is applied. During the test, observations we recorded covering all important parameters like ultimate compressive load, shear strength, deflection due to compressive and lateral loads and behaviour of steel strips under vertical and horizontal loading. Load carrying mechanisms are observed, varying from the initial, uncracked state, to the final, fully cracked state. The results demonstrate that a significant increase in compressive and shear strength can be achieved by anchoring strips and polypropylene fibre to the surface of masonry wall.