CFRP Strengthening of Concrete Structures using Modified Adhesives

  • Miss Rawaa Al-Safy, Department of Civil Engineering, Monash University, Melbourne, Australia
  • Prof Riadh Al-Mahaidi, Faculty of Engineering and Industrial Sciences, Swinburne University of Technology, Melbourne, Australia
  • Prof George Simon, Department of Materials Engineering, Monash University, Melbourne, Australia

Fibre Reinforced Polymer (FRP) composites have been widely used for retrofitting of concrete structures. For external retrofitting, CF-fabrics are bonded to the concrete surface using adhesive bonding. In this system, adhesives are the most sensitive elements to temperatures close to, or exceeding their glass transition temperatures (Tg). At these temperatures, significant reduction in the mechanical properties of the adhesives occurs which results in rapid deterioration of the whole retrofitting system. This paper presents an experimental investigation on modifying the bonding agent between CF-fabrics and concrete members to improve the CFRP/concrete performance at elevated temperatures. This was achieved by adding different percentages of nanomaterials to a commercially available epoxy adhesive. High functionality resin (DGOA) was used as well for the modification. The glass transition temperatures of the modified and unmodified adhesives were measured using Dynamic Mechanical Thermal Analysis (DMTA) technique. Evaluation of CFRP/concrete bond was carried out using adhesive pull-off tests and single-lap shear tests.