Deflections of concrete members reinforced with fibre-reinforced polymer (FRP) bars.

摘要

In recent years, use of fibre reinforced polymer (FRP) bars as substitute for steel reinforcing bars, to avoid corrosion, is increasing. This thesis analyses previously published data and the results of experiments conducted at the University of Calgary to determine the most accurate method of predicting immediate and long-term deflections of concrete members reinforced with FRP bars. The analysis conducted in this thesis compares experimental deflections of FRP reinforced concrete members to theoretical values calculated using the following design codes for steel reinforced concrete members: CSA A23.3-94 (ACI 318-95) and CEB-FIP Model Code 1990. The results of the analysis show that CEB-FIP Model Code 1990 accurately predicts both immediate and time-dependent deflections and that CSA A23.3-94 (ACI 318-95) under-estimates immediate deflections and over-estimates time-dependent deflections.; Due to the low elastic modulus of FRP bars compared to steel, the design of concrete members with FRP reinforcement will most likely be governed by deflection and crack width. This thesis gives equations that can be used in design to select the span-to-depth ratio of members reinforced with FRP bars. The members selected using the span-to-depth ratio equations should not have excessive deflection in service conditions.