Effect of Pre-stress in Steel Strips to Strengthen Unreinforced Brick Masonry Walls under Axial Loads

Abstract

Using steel strips to strengthen the existing unreinforced masonry walls has competitive advantages, which includes no wet work, avoidance of formwork, time saving, ease of installation, minimal increase of dimensions, no requirement for material strength of the existing walls and good reversibility. In this paper, seven specimens were fabricated and tested under axial loads for obtaining the effect of pre-stress in steel strips to strengthen unreinforced brick masonry walls. Test results showed pre-compression stress in the vertical steel strips could increase the load of cracks in the single brick in the wall, otherwise steel strips only improved the load of continuous cracks and the failure load, and the axial stiffness of the wall; when the transverse steel strips were pre-tensioned, it could further improve the failure load and the later axial stiffness of the strengthened wall.