Grant: Alliance Grants

Glass fibre reinforced polymer (GFRP) composite reinforcing bars are an attractive alternative to conventional steel bars in reinforced concrete bridge construction due to their high strength and non-corrosive properties. GFRP reinforcement has become widely accepted over the past two decades but the body of research on their behaviour and performance is still limited in comparison to research related to steel reinforcement. One specific problem that has never been investigated is the effect of damage and contamination on the performance of internal GFRP reinforcing bars. During construction, abrasive blast cleaning/roughening of steel and existing concrete surfaces, and new concrete placement operations are commonly carried out in close proximity to exposed GFRP reinforcing bars. Damage to GFRP bars from abrasive blasting and surface contamination from concrete placement operations (e.g., concrete splatter) have the potential to adversely affect their strength and durability properties but there is no known research on the impact. Currently, it is conservatively assumed that abrasive blasting and contamination are detrimental to the performance of GFRP bars and affected bars must be replaced which is costly and time-consuming. This research project will use advanced imaging and nondestructive testing methods to analyze the impact of abrasive blasting and surface contamination on the integrity of GFRP bars and evaluate their effects on mechanical properties, bond behaviour, and durability. The results from the experimental program will be used to develop inspection guidelines and material rejection criteria. GFRP bars of varying diameter and surface finishing will be obtained from MTO designated sources and subjected to varying degrees of abrasive blasting and contamination in the lab before being tested. This research will provide the MTO with more certainty in the use of internal GFRP reinforcing bars, reduce conflicts during construction, and reduce construction time and cost.