Experimental Investigation on Flexural Behavior of Masonry Prisms Strengthened by Fiber-Reinforced Mortar Layer

Abstract

The out-of-plane damage of unreinforced masonry (URM) walls in earthquakes may endanger gravity load carrying system which can result in partial or total collapse of the masonry buildings. Most of the proposed retrofitting techniques for the URM walls cannot be used in practice in developing countries. Thus, this study focuses on experimental evaluation of a simple practical retrofitting technique employing fiber-reinforced mortar (FRM) surface layer. In this research, the out-of-plane behavior of masonry prisms retrofitted by ordinary FRM layer is evaluated through a comprehensive experimental program. Polypropylene (PP) and steel fibers are used in the FRM mixes. Influence of type and amount of fiber in the FRM mix, surface layer thickness and retrofitted face of the masonry prism (one side or two side) on the flexural behavior of masonry prisms are investigated. One-third-point-loading test is conducted to find flexural strength and load–displacement curves. Results of tests show that retrofitting with FRM surface layer can increase flexural capacity considerably. This increase mainly depends on thickness of the surface layer, rupture modulus of the FRM mix and retrofitted face. Test results indicate that employing steel fiber is more efficient than PP fibers.