A comparison of existing analytical methods to predict the flexural capacity of Ultra High Performance Concrete (UHPC) beams

Abstract

Ultra High-Performance Concrete (UHPC) shows enhanced performance and ductility compared to conventional concrete which can be beneficial in the construction industry. Many researchers have performed experimental studies on the structural behavior of the UHPC beams to establish a reliable analytical method to calculate the flexural capacity of the section. However most of these studies were performed through limited specimens due to the high cost of UHPC. The objective of this paper is to compare the accuracy of well-known existing methods to calculate the moment capacity of a reinforced UHPC beam through a parametric study. To that aim, several small-scale beams were constructed and tested to evaluate the flexural behavior and ultimate moment capacity of the UHPC beams. The performance of the tested specimens is discussed regarding the moment capacity, load-deflection curves, crack development and the modes of failure.The obtained results through the experiments were, then, used to validate the Finite Element (FE) model. Comparing the numerical and experimental results indicates that generally, the proposed numerical model can predict the structural behavior of the UHPC beams reasonably. Hence, the validated FE model was employed as a reference point to evaluate the existing analytical approaches to calculate moment capacity of UHPC beams. A series of large-scale beams with different geometries and reinforcing details were numerically simulated, and the results were compared with the results obtained through the analytical methods. The results showed that some of existing methods can predict the ultimate moment capacity of the UHPC beam with an acceptable accuracy.