DURABILITY OF CONCRETE BEAMS REINFORCED WITH GFRP BARS UNDER DIFFERENT ENVIRONMENTAL AND LOADING CONDITIONS

摘要

This paper presents the test results of 14 concrete beams reinforced with two types of glass FRP composite bars: Sand-coated and Ribbed-deformed bars. The beams are 1800 mm long with a rectangular cross-section of 130-mrn width and 180-mm depth. The individual and coupled effects of freeze/thaw cycles and sustained bending stresses on the long-term behaviour of concrete beams reinforced with GFRP composite bars were investigated. The beams were exposed to 100 freeze/thaw cycles (-20 ℃ to +20 ℃) either in an unstressed state or loaded in bending to 1.4 times of its cracking moment, which represents 23% to 27% of the GFRP bare bar ultimate tensile strength. The conditioned specimens were tested up to failure in a four-point bending set-up over a clear span of 1500 mm. The test results showed that no significant effect for the coupled action of freeze/thaw cycles and sustained bending stresses on the behaviour of the tested beams.