Creep effect on the behavior of concrete beams reinforced with GFRP bars subjected to different environments

The effect of different environmental conditions on the creep behavior of concrete beams reinforced with glass fiber reinforced polymer (GFRP) bars under sustained loads is investigated. This is achieved through testing concrete beams reinforced with GFRP bars and subjected to a stress level of about 20–25% of the ultimate stress of the GFRP bars. Reference beams were loaded in the temperature-controlled laboratory (24 ± 3 °C). Other test beams were either completely or partially immersed in different environments (tap-water and sea-water) at elevated temperature (40 ± 2 °C) to accelerate the reaction. During the exposure period, which lasted for ten months, strains in concrete and GFRP bars as well as the midspan deflections were recorded for all considered environmental conditions. The results show that the creep effect due to sustained loads was significant for all environments considered in the study and the highest effect was on beams subjected to wet/dry cycles of sea-water at 40 ± 2 °C.