Single fiber pullout from hybrid fiber reinforced concrete

Abstract

Hybrid fiber reinforcement can be very efficient for improving the tensile response of the composite. In such materials, fibers of different geometries can act as bridging mechanisms over cracks of different widths. The fiber bridging efficiency depends on the interface properties, which makes interface characterization very important. Therefore, single-fiber pullout tests from conventional matrices as well as from the fiber reinforced mortar matrices are performed. The composition of the mortar matrix has been varied as well. The pullout response of single fibers generally improves with increasing percentage of fibers in the mortar. Moreover, pullout forces are generally higher when the matrix has a higher strength. In all these cases, intensive microcracking of the surrounding matrix can be observed during fiber pullout. Together with single-fiber pullout tests, standard compression tests and splitting tensile tests, as well as workability studies have been performed, in order to provide experimental data for further research of the high-performance hybrid fiber reinforced concrete.