Nonlinear semi-numeric analysis and simplified analysis of polymer fiber-reinforced concrete prisms under three-point bending test conditions

Faculty of Civil Engineering, Transportation Engineering and Architecture, University of Maribor, Smetanova ulica 17, 2000 Maribor, Slovenia

^* Corresponding author: ziga.unuk@um.si

Abstract

This paper presents a semi-numeric nonlinear analysis and a simplified analysis for evaluating the load-displacement behavior of polymer fiber-reinforced concrete elements under three-point bending test conditions. The considered elements were notched and unnotched prisms. The nonlinear semi-numeric analysis was based on the moment-curvature relation, plastic hinge approach, and virtual work method. The simplified analysis assumed multilinear load-displacement behavior of the prisms under three-point bending test conditions. It included four variants for the input tensile strength properties and crack widths considered for the serviceability and ultimate limit state. The notched polymer fiber-reinforced concrete prism three-point bending test results from a prior study were the basis for evaluating the simplified analysis, which was subsequently compared with the nonlinear semi-numeric analysis outcomes from the same investigation. Additionally, the simplified analysis and the nonlinear semi- numeric analysis were used to determine the load-displacement behavior of unnotched polymer fiber-reinforced concrete prisms with heights ranging from 25 mm to 250 mm. The results indicate that the simplified analysis provides a practical and efficient method for estimating the behavior of polymer fiber-reinforced concrete structures under three-point bending test conditions, yielding relatively accurate results with minimal computational effort compared to the more exact nonlinear semi-numeric analysis.