Probabilistic evaluation of the design development length of a GFRP rod pull-out from concrete

With an additional target reliability index of 1.098, the Rackwitz–Fiessler method was used to evaluate the coefficients associated with the design development length of a GFRP rod in concrete in the case of pull-out bond failures. As a result of the evaluation, the coefficients are proposed to be 0.0816 and 0.0933 for ordinary and aggressive exposures, respectively. The coefficient of variation of GFRP strength could exert the most significant influence on averaged coefficients. The effects of diameter and GFRP average strength greater than 750 MPa are found to be negligible. A linear relationship between the averaged coefficient and additional target reliability could be employed for developing a performance-based bond design methodology. With the combination of flexural analysis, the proposed relationship between the averaged coefficient and the so-called strength utilization factor could be applied to for the determination of a customized design development length of a GFRP rod in concrete.

► The specifications on the design development length of steel reinforcing bars cannot be applied directly to FRP rods.
► The coefficients associated with GFRP’s design development length are proposed to be 0.0816 and 0.0933 for ordinary and aggressive exposures.
► The C.O.V. of GFRP strength could exert the most significant influence on averaged coefficients.
► A linear relationship between the averaged coefficient and additional target reliability could be attained.