UBC Theses and Dissertations
Durability of spray applied glass fibre reinforced polymers externally applied to concrete subjected to a simulated marine environment Dolan, Kyle
Across Canada and around the world the need for rehabilitation of aging infrastructure is becoming a growing problem. Two major causes of this deterioration are corrosion of the reinforcing steel and increased service loads. Traditionally steel jackets and reinforced shotcrete have been utilized as repair materials, but these materials have many downfalls, such as the corrosion of steel and high unit weights. In recent years the use of fibre reinforced polymers for rehabilitation and strengthening of structures has become common practice. More recently, a new technique of applying these materials has been developed at UBC. The technique utilizes compressed air to pneumatically apply resin and short fibres to the surface of concrete resulting in an isotropic composite. These initial studies proved the material to perform as well as, or better than unidirectional fibre reinforced wraps and jackets. The durability of the material is unproven. The research described within this thesis evaluated the durability of sprayed glass fibre reinforced polymers (SGFRP) applied to concrete substrates subjected to a marine environment. The SGFRP material was applied at various thicknesses and fibre contents to small concrete cylinder and beam specimens. The intent of the study was to evaluate these materials as a structural coating and a protective coating. The cylinder specimens were coated, exposed to an accelerated marine environment for 175 days, and evaluated against control specimens to determine the effects of preloading and the marine exposure period. The application of coating was found to greatly increase strain capacity and the fracture toughness of the concrete when loaded in compression. The beam specimens were coated on the underside of each beam, exposed to an accelerated marine environment for a maximum of 175 days, and evaluated against control specimens to investigate the effects of the exposure period, and various coating thicknesses. The study illustrated that the efficiency of the SGFRP application decreases as the coating thickness increases. The ultimate load carrying capacities of the beam specimens was found to decrease after the 175 day exposure period. The findings of the study suggest that Sprayed FRP material would perform well when used for retrofit of concrete structures. In addition to performing well structurally, these materials are lightweight and relatively easy to apply. However, further research should be carried out to evaluate the durability of Sprayed FRP materials prior to commercial use.
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