THERMAL COMPATIBILITY OF PLASTIC COMPOSITE REINFORCEMENT AND CONCRETE

摘要

Composite rebar are typically uni-directionally reinforced, that is, none of the fiber in the rebar itself is placed in the transverse direction. Due to this lack of transverse fiber in the composite rebar, the transverse coefficient of thermal expansion (CTE) of composite rebar is much higher than its longitudinal CTE. In this research, the transverse CTE of E-Glass/ vinylester composite rebar is shown to be approximately 3 times higher than that of concrete. This transverse thermal incompatibility may cause significant bursting-type stresses within concrete members reinforced with composite reinforcement and eventual deterioration of the bond between composite rebar and concrete. The longitudinal CTE of composite rebar is shown to be near that of concrete. The spiral wrapping used in many commercial composite rebar is shown to restrict the transverse movement of the unidirectional core during thermal cycling. Regions away from the spiral swell nearly as much as do unwrapped smooth composite rods with similar compositions.