OPTIMISATION OF STEEL FIBRES REINFORCED CONCRETE MIX DESIGN

Cementitious matrices are the fragile materials that possess a low tensile strength. The addition of fibres randomly distributed in these matrices, improve substantially their cracking strengths. However, the incorporation of fibres into a plain concrete disrupt the granular skeleton and causes very quickly problems of mixing as a result of the loss of mixture workability that will be translated into a difficult concrete casting in site. This study was concerned on the one hand with optimising the fibres reinforced concrete mixes in the fresh state, and on the other hand with assessing the mechanical behaviour of this mixture in the hardened state, in order to establish a compromise between the two states. In the first part of this paper, an experimental study of an optimisation method of fibres reinforced concrete while taking account of some parameters related to the matrix is presented, eg volume of admixture, volume of incorporated fibres and the volume of water and, cement (W, C) in function of workability time. Finally, test specimens of mixture optimised by this method have been tested in compression and tensile by bending. The results have been compared to those of mixture test specimens optimised by Baron – Lesage method.

• ABSTRACT

• INTRODUCTION

• TEST PROCEDURES

• MATERIALS AND EQUIPMENT

• TESTING

• ANALYSIS OF RESULTS

• RESULTS AND DISCUSSION

• CONCLUSIONS

• REFERENCES