Freeze-thaw behaviour of circular concrete members confined by fibre reinforced polymer jackets when simultaneously subjected to sustained axial loads.

摘要

This thesis presents results of an experimental study on the durability performance of concrete cylinders confined with glass-FRP (GFRP) sheets, carbon-FRP (CFRP) sheets, or prefabricated GFRP tubes (GFRP-T). The study includes 146 plain and FRP-confined concrete specimens of which 126 specimens were standard 150 x 300 mm concrete cylinders and 20 specimens consisted of 167 x 334 mm concrete-filled GFRP tubes. The concrete filled GFRP tubes are mainly considered for new structures and not for rehabilitation p urposes. One half of each group was made of normal weight concrete while the other half was made of lightweight concrete. FRP-confined specimens from each group were subjected to sustained axial compressive stresses of 40--50% of their respective confined strength using specially fabricated steel loading frames. Some of these specimens were then subjected to 300 freeze-thaw cycles with a temperature range of +4°C to -18°C in accordance with ASTM C666, using a large environmental chamber. (Abstract shortened by UMI.)