The invention concerns a microgranular concrete composition and microgranular aggregates, further comprising 1 p to 80 p of metal fibres derived at least partly from a first group of fibres with length ranging between 20 and 100 mm and with diameter ranging between 100 and 500 mu m, and for the remainder a second group of fibres with length ranging between 1 and 20 mm and with diameter ranging between 100 and 300 mu m.