A powder including, in percentages by weight: (a) 94% to 99% of particles of at least one refractory material, the main constituent(s) of which are alumina and/or zirconia and/or silica; (b) 1% to 6% of a hydraulic cement; (c) 0 to 0.03% of organic fibers; (d) optionally, 0.075% to 1% of a surfactant; and (e) optionally, a setting accelerator, where the fraction of particles having a size below 40 μm being distributed, in percentages by weight relative to the weight of the powder, in the following manner: (1) fraction