Direct Service Temperature Exposure Effect on Bond Behaviour between NSM Composites and Concrete Masonry Units

The durability of fiber reinforced polymer (FRP) for strengthening structural elements has been ratherextensively studied in the literature. The influence of directly applying temperature on bond behaviourrepresents an open topic that needs to be considered in more detail. This study is one of the initialstudies to investigate the advanced composite bond behaviour when subjected to tension forcesimultaneously with applying temperature. The temperatures considered in this study were at freezing -18 ⁰C (0 ⁰F), ambient 21⁰C (70 ⁰F), and high service temperature 49 ⁰C (120 oF), which covers muchof the spectrum of structural element service temperatures in the field. The key parameters investigatedinclude different strengthening system under different level of temperature. Specimens were subjectedto single-lap direct shear simultaneously with applying temperature, while other specimens were testedafter exposure to the cycles of heating and cooling temperature. The results showed a high reductionof FRP-epoxy bond properties up to 59% when exposed to high service temperatures