Non-destructive detection of corrosion of ECR
Epoxy coated rebar (ECR) is extensively being used in bridge decks in North America. An intact epoxy coating prevents corrosion of the steel reinforcement by building a barrier between the steel and de-icing salts and water in the pore structure of the surrounding concrete . However, too often the epoxy coating is damaged during transportation and placement which results in localized corrosion of the reinforcing steel. Detecting this corrosion non-destructively poses a challenge that Brigitte Goffin is facing in her research. The suitability of a variety of non-destructive testing (NDT) methods is investigated as well as the corrosion behaviour of ECR.
Biodeterioration of concrete
Thousand kilometers of pipelines must be removed each year for replacement suffering from severe bacterial induced corrosion which is caused by prolonged exposure of concrete to highly aggressive environments. Concrete corrosion in these environments is mainly caused by the diffusion of aggressive solutions and in situ production of sulfuric acid by sulphur oxidizing microorganisms which affects the physicochemical properties of concrete.
Over the past several decades many approaches were attempted to protect structures exposed to aggressive environments from microbiologically influenced concrete corrosion with varying degrees of success. Negar Roghanian is aiming to enhance wastewater pipes durability by developing a coating material not only to prevent concrete bio-corrosion but also extend the bio-resistance life time and efficiency of biocidal activity and shielding biocides from environmental disclosure.
Surface characteristics of PP fibres
The inadequacy of polypropylene (PP) fibre application in fibre reinforced concrete (FRC) is the low performance on bonding characteristic with cement matrix compared to other types of fibres. The poor bonding of PP fibre is due to its low surface energy traceable to its hydropobic behavior and smoothness and its low roughness. Therefore improvement in interfacial bonding between fiber and matrix by surface modification of the fiber such as filler or coating might enhance the benefit of using this material in concrete. Ricky Ratu’s research project is focus on the development of method to improve the surface characteristics of the fiber by inclusion of by-product materials during the extrusion proses of the fiber.
Development of novel FRP fibres
A high strength high modulus fibre that is resistant to corrosion or deterioration can be produced by reinforcing a high performance fibre such as glass or carbon fibre in a matrix of resin such as epoxy. The construction industry knows this material as fibre reinforced polymer composite (FRP). Mohammed Farooq is attempting to develop a novel FRP fibre and is testing its performance. The performance measures include simple tensile and bond slip tests, effect of temperature, effect of rate of loading, relaxation and effect of accelerated deterioration on bond-slip behaviour of the FRP fibre.