Flexural strength prediction models of non-prestressed Ultra-High Performance Concrete (UHPC) components

The use of Ultra-High Performance Concrete (UHPC) has been growing rapidly in the past two decades because of its superior mechanical and durability properties compared to conventional concrete (CC). Flexural strength prediction models of CC components underestimate the flexural strength of non-prestressed UHPC components as they ignore the tensile strength of concrete and assume different stress–strain relationships and failure mode from those of UHPC. The objective of this paper is to evaluate the current flexural strength prediction models of non-prestressed UHPC components using test data collected from the literature and validate them using experimental data of a UHPC ribbed slab tested in flexure. Measured and predicted flexural strengths are compared at different curvatures. Evaluation results indicated that neglecting the tensile strength of UHPC significantly underestimates the flexural strength of non-prestressed UHPC components. Peak moment curvature of non-prestressed UHPC components is significantly smaller than ultimate moment curvature. In addition, the differences among idealized stress–strain relationships of UHPC in compression and tension do not have significant effect on the predicted flexural strength.