Barcelona test for the evaluation of the mechanical properties of single and hybrid FRC, exposed to elevated temperature

The mechanical behaviour of single and hybrid FRC mixtures, with one type of steel and two types of polypropylene fibres at 0.5% and 1.0% volume fractions, is investigated through the double punch Barcelona test. Indirect tensile strength and toughness characteristics are evaluated at ambient temperature and after heating of the specimens at 280 °C. It is shown that the modified toughness estimated through Barcelona test may be a suitable index to classify FRC in terms of ductility, both for the unheated and for the heated specimens. It was also found that hybrid FRC, containing an appropriate amount of different fibre types, is superior in terms of ductility compared to the single FRC. Finally, equations are proposed for the calculation of the Total Circumferential Opening Displacement (TCOD) values by using the axial displacement measurements, considering basic characteristics of the fibres and of FRC mixture, such as fibre's length, rupture strength and volume fraction, respectively.