so that if desired a rear wheel may be attached to the body to maintain the body in a fixed position above the ground the trailing end of the body 11 supports a hopper assembly 17 having an open bottom extending between opposed longitudinal side walls 18 between which the selected mold such as a stepped mold 19 illustrated is secured the mold 19 is supported beneath the trailing portion of the body 11 and extends rearwardly thereof the lower longitudinal edges of the mold 19 are arranged to rest upon the ground as illustrated in fig3 the hopper 17 feeds material towards the inlet end 20 of the mold 19 and a pusher assembly 21 is supported for pivotal movement through the lower portion of the hopper 18 so as to force concrete mix in use rearwardly through the mold 19 the pusher assembly 21 is illustrated in dotted outline in its forward position and it is reciprocated between its rear and forward positions by drive means as hereinafter described in this embodiment the pusher assembly 21 includes a planar pusher plate 22 fixed rigidly to a top mounting plate 23 the rear portion of which is supported from upwardly extending mounting bars 24 which connect to the side walls 25 of the body 11.