Three-parameter Weibull distribution model for tensile strength of GFRP bars based on experimental tests

Abstract

Concrete structures with fibre-reinforced plastic bars can solve steel corrosion problems very effectively. At present, glass fibre-reinforced plastic bars are more widely used among fibre-reinforced plastic bars. Different from steel bars, glass fibre-reinforced plastic bars have no yield stage before fracture, which means concrete structures with glass fibre-reinforced plastic bars will not suffer ductile failure but only brittle failure without warning. Therefore, it is of particular importance to accurately obtain a standard value of the tensile strength of glass fibre-reinforced plastic bars. This paper carried out tensile tests of glass fibre-reinforced plastic bars with different diameters, measured the ultimate tensile strength and elasticity modulus of glass fibre-reinforced plastic bars, and conducted regression analyses. Based on the test results, a three-parameter Weibull probability distribution model was proposed, model parameters were fitted, and the results of the experimental tests were compared to that of the Weibull distribution model and the normal distribution model. At last, the relationship between the tensile strength and effective volume of glass fibre-reinforced plastic bars was discussed and a formula which can calculate the standard values of tensile strength of glass fibre-reinforced plastic bars with different diameters was obtained.

Keywords:

• GFRP bars
• Tensile strength
• Weibull distribution
• Normal distribution
• Concrete structure