Experimental analysis of the efficiency of carbon fiber anchors applied over CFRP to firebrick bonded joints

Abstract

In these recent years, the strengthening of masonry building has known a massive use of CFRP sheets. Those composite materials glued on the elements to reinforce are exposed to prematurely debonding crisis due to a tension load which is much smaller than the tensile strength of the CFRP. A way to upgrade failure load of CFRP-to-support bonded joint is to reinforce the cohesion between the fibers and the support by the use of mechanicals anchors built with the same fibers of the composite and fastened in the support like nails . Research on the use of anchors for masonry supports has been limited and there are no experimental analyses related to the design and the placement of fiber anchors. The aim of this thesis is to provide experimental data to quantify the efficiency of the carbon fiber anchors applied on a reinforced fire brick. This is a ground work to study CFRP to masonry bonded joint fastened by fiber nails . Specifically, the analysis of the displacement and the strain fields of the reinforced surface have been realized by means of Digital Image Correlation (DIC), an optical appealing method never used to study a FRP to support bonded joint fastened by FRP anchor. The experimental analyses shown that the CFRP anchors applied onto a CFRP to support bonded joint permit to achieve two main advantages: 1) The increase of the maximal load peak 2) The attribution of a resistance post peak, and therefore, the increase of the ductility of the reinforced system.