| FRP reinforcing bars are the alternative to steel reinforcement to solve the corrosion problem of structural concrete subjected to aggressive environments. However, partly, due to inadequate comprehensive data with regard to the interfacial bond force between FRP rebar and concrete, their application in the civil infrastructure system has been slow. This is the focus of this dissertation. The main objective was to propose design criteria for the development and splice lengths for straight FRP reinforcing bars in tension. This was accomplished through an extensive, systematic experimental program, in which 151 pullout, 66 splitting, and 26 beam specimens were constructed and tested under static monotonically increasing load until failure. Hence, for each reinforcing bar, load versus displacement curve, bond stress-slip constitutive relationships and the mode of failure were experimentally determined.; An analytical evaluation of the test results was carried out to compare the bond stress from the different test procedures. The bond stress is expressed as a function of concrete compressive strength for the different bar diameters. Furthermore, some expressions for the bond splitting strength, given in the literature were used to evaluate the splitting test results. The average bond stress varies with the concrete compressive strength.; Based on this research, a proposal for the average bond stress of FRP reinforcing bars in normal strength concrete is made, which is an expression that is a function of bar diameter, and concrete compressive strength. Consequently, for determining the development length of straight FRP reinforcing bars in tension, that are confined by transverse reinforcement, a proposal is made. The expression is a function of bar diameter, concrete compressive strength, and design tensile strength of bar. It provides a more economic development length than do the earlier expressions. Hence, resulting into a saving of about 20% on the development length and more durable FRP reinforced concrete structures. Additionally, an expression given in the literature is recommended for the average bond splitting strength. |
