Page 298 - Masonry and Concrete

Paving

297
PAVING

brick, stone, or broken concrete. Be sure to keep the fill at least 4 in.
away from the side forms, the riser forms, and the top of the treads and
landing. This will assure that you get a minimum 4-in. thickness of
concrete over and around the fill material. Place a sheet of wire mesh
reinforcement in the form (Figure 8-21), holding it back from the edges
about 3 in. so that it will be completely embedded. Start pouring the
concrete in the bottom step. Fill the next step with a shovel, tamp the
concrete to fill in corners, and settle the concrete against the forms by
tapping the outside of the forms lightly with a hammer.
Steps that are not supported by earth fill must be self-supporting.
The bottom form should be made of 1 6 lumber because it will carry
considerable weight until the concrete cures and attains strength. Sup-
porting posts under the form should be 4 4s. To provide the struc-
tural capacity needed, steel reinforcing bars are required to add tensile
strength. Reinforcing bars should be sized and spaced according to the
length and thickness of the steps (Figure 8-22). Forms and shoring
should be left in place for at least one week before the concrete can
support itself.

REINFORCING MESH

4" MIN.

FILL MATERIAL

FIGURE 8-21

Reinforcing mesh in step forms.

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