Production and Properties of Functionally Graded UHPFRC Beams

Abstract

Ultra-High Performance Fibre Reinforced Concrete (UHPFRC) is a fine-gained composite material achieving both high compressive and tensile strengths. Values of compressive strength, tensile strength and bending strength depend not only on a composition of the mixture itself, but also on the border conditions of the setting of the test, it means the support type, the loading rate etc. UHPFRC is used not only in European countries (Germany, France, Holland), but in distant countries (USA, Japan, Australia), too. In the Czech Republic is UHPFRC produced mainly in laboratories. The first using of UHPFRC for the real construction in the Czech Republic was a production of lost shuttering slabs that were used at the reconstruction of the raod-bridge across R10 highway. These results of the lost shuttering slabs became the base of a more detailed research of the homogeneity of the steel fibre distribution and its impact on load bearing capacity of the UHPFRC elements. Experimental beams with a different volume fraction of steel fibres were made and tested on the basis of the determined results of a nonhomogeneous fibre distribution at the cross section of lost shuttering slabs. Then the layered beams with a controlled steel fibre distribution at the cross section were made and tested too. The test results together with a description and characterization of the behaviour of tested homogeneous beams with different volume fraction of the steel fibres and functionally layered beams are published in this paper.