Feasibility of Reducing the Fiber Content in Ultra-High-Performance Fiber-Reinforced Concrete under Flexure
In this study, the flexural behavior of ultra-high-performance fiber-reinforced concrete (UHPFRC) is examined as a function of fiber length and volume fraction. Straight steel fiber with three different lengths (lf) of 13, 19.5, and 30 mm and four different volume fractions (vf) of 0.5%, 1.0%, 1.5%, and 2.0% are considered. Test results show that post-cracking flexural properties of UHPFRC, such as flexural strength, deflection capacity, toughness, and cracking behavior, improve with increasing fiber length and volume fraction, while first-cracking properties are not significantly influenced by fiber length and volume fraction. A 0.5 vol % reduction of steel fiber content relative to commercial UHPFRC can be achieved without deterioration of flexural performance by replacing short fibers (lf of 13 mm) with longer fibers (lf of 19.5 mm and 30 mm).
Finite element modelling to predict the flexural behaviour of ultra-high performance concrete members
Abstract This paper presents a finite element (FE) modelling to predict the behaviour of ultra-high performance concrete (UHPC) members under static flexural loading. A plasticity-based constitutive model for concrete and an implicit solver in LS-DYNA were adopted in the numerical simulation. Experimental data for 21 UHPC specimens tested in the present study and in previous works were used to calibrate and validate the proposed FE model and modelling technique. The simulation was able to accurately predict the experimentally obtained ultimate strength, stiffness, and hardening and softening behaviours of the specimens. This demonstrates the effectiveness and adequacy of the developed FE model and modelling technique.
Fédération Internationale du Béton (fib), Model Code 2010 - First complete draft, chapters 7.3 and 7.13
Keywords: beton arme ; dimensionnement ; effort tranchant ; poinconnement ; theorie de la fissure critique ; reinforced concrete ; design ; shear force ; punching ; critical crack theory Reference EPFL-CHAPTER-164600 Record created on 2011-03-31, modified on 2016-08-09