Web Application Tool for Characterizing UHPFRC Tensile Properties

A numerical tool for characterizing the tensile properties of Ultra-High-Performance Fiber-Reinforced Concrete (UHPFRC) is presented. The application is based on a model capable of reproducing the load-deflection behavior of prismatic unnotched UHPFRC specimens under the Four-Point Bending Test (4PBT) scheme, which enables the implementation of numerical methodologies for the characterization of UHPFRC tensile properties based on inverse analysis. The constitutive behavior considered takes into account three distinct branches, encompassing both strain hardening (SH) and strain softening (SS) behaviors. The constitutive behavior is implemented in a non-linear section analysis to consider the crack development. Moreover, the sectional behavior is implemented at a structural level through a non-linear hinge model. Therefore, the numerical model allows for an immediate analysis of the load-deflection response behavior with respect to those variables that influence the 4PBT. This includes those specific parameters that define the UHPFRC material behavior as well as those ones that determine the test typology and the geometry of the specimens. The numerical application also includes an iterative inverse analysis method enabling the automatic search for the tensile properties given a load-deflection experimental response. Both the numerical model and the iterative method have been coupled in a web application allowing the UHPFRC analysis and characterization process to be carried out quick and easy in any field of work. The numerical model and the iterative inverse analysis method have been validated by comparing their response with previous experimental works of characterization. Overall, the developed application proved to be a simple and reliable tool that enables an intuitive graphical analysis of the behavior of UHPFRC 4PBTs.