A material spreader is used to apply one of several types of material, including floor hardeners, coloring materials, light reflectants, and aggregates. On truss-type spreaders, the spreader's bridge section straddles the form, with an operator on each end of the bridge. Material is placed in the spreader's hopper and the hopper moves across the bridge at a controlled speed, releasing the material onto the slab. Once the hopper reaches an end of the bridge, the hopper is put in the neutral position and the spreader is slid down the sides of the form to the appropriate spot. Telescopic-boom material spreaders work in a similar fashion. A hydraulically driven, self-propelled spreader head, which stores the material falling onto the surface, is attached to a telescopic boom, which is part of a ride-on machine. An operator drives the machine along one side of the form, moving in increments equivalent to the pour's width. The telescopic boom, which cantilevers from the ride-on machine at various lengths, carries the spreader head across the slab as material is released.
