Shear assessment of failed RC beams retrofitted by sisal mat polymer composite

Abstract

Retrofitting deteriorate structures in order to maintain and enhance the load-carrying capacity to upgrade structural components is necessary and has several economic and environmental advantages over demolition and reconstruction. The used of locally available materials, allowing the use of local skills, benefitting to the local economy and being low in cost for retrofitting should have greater priority for researchers in the field of structural engineering. In this paper, the assessment of failed RC beams retrofitted by sisal mat polymer composite externally bonded by strips on critical regions (SCR) is presented. Sisal fiber is one of the most available natural fibers and the eastern part of Africa is one of the biggest producers, so the application of sisal polymer composite as structural retrofitting needs to be investigated. The study focuses on a shear assessment where four beams were tested in three- point bending with two retrofitted after cracking and two as control specimens. By using strips in critical regions through main cracks, it was found that the sisal mat composite is suitable as raw material and increases the load- carrying capacity, reduce cracks propagation and modify the failure mode from pure shear to more ductile flexural- shear.