Characterisation of fibre reinforced concrete mechanical properties: A review

Steel Fibre Reinforced Concretes have been extensively studied. Right now, powerful characterisation methods of FRC properties have to be used in order to give to structural engineers pertinent data's allowing them to design elements. In this paper, classical tests are reviewed and flexural test is analysed in details as characterisation method of mechanical FRC properties. The limits of toughness indexes defined in terms of area under load-deflection curves are put straight forward and it is shown that such indexes can not be used for FRC prescription in the frame of structural design. A new approach is proposed to extract from flexural test result a tensile stress-crack opening relation. For a better accuracy, it is proposed to run flexural test by using notched specimen and then recording directly crack opening. As the specimen is representative of fibres distribution which may be obtained in structure, such dual approach allows to obtain directly intrinsic characterisation relation of tensile FRC properties. According to the used model, this relation is unique and allows the analysis of FRC properties with an objective point of view.