cen:proj:83242

Testing hardened concrete — Part 22: flexural strength and fibres contribution of UHPFRCs on thin plates cen:proj:83242

Scope

This document specifies the procedures for characterising the tensile performance of UHPFRCs through bending tests, the orientation of the fibres is influenced by a reduced member thickness relative to the dimension of the fibres. It is accepted that this influence occurs for a thickness less than 3 times the length Lf of the longest fibres contributing to non-brittleness
The four-point bending test on thin plates described below results in a measurement of the deflection as a function of the force applied. The method of processing the data from these tests enables an equivalent response curve for the material under direct tension to be determined by inverse analysis. Using this analysis, the multi-cracking behaviour expected is described by a stress-strain law which makes it possible to ascertain the limit of the linear behaviour, the contribution of the fibres as reinforcement to a cracked section and to determine the tensile behaviour class by using a conventional transformation of the strain into a crack opening, to satisfy the inequality ensuring a sufficiently strain hardening behaviour.