Comparison of Recent Shear Capacity Models Against Experimental and Simulation Databases of Ultra-High-Performance Concrete Beams

Abstract

This paper reports on an evaluation of two models for calculating the shear strength of prestressed ul¬tra-high-performance concrete (UHPC) beams. Cal¬culations from these models, referred to as the eCPCI and FHWA (Federal Highway Administration) models, were compared to a database of experimental test results compiled from the literature. Identifying comparable UHPC material properties from the published literature was a challenge because different testing programs used different material tests. Accordingly, UHPC localized tensile strength was estimated based on the available data and approximate ratios. In addition to the experi¬mental database, a machine-learning prediction model was developed to generate a simulation database used for further evaluation of the eCPCI and FHWA models. On average, the FHWA model resulted in shear capacity estimates that were 17% lower than the eCPCI method. However, the analyses show that shear strength predic¬tions from both the FHWA and eCPCI models were typ¬ically conservative relative to data from the experimental and simulated databases. In addition, both models were observed to produce less-accurate estimates for larg¬er-sized specimens than for smaller specimens.