Figure 7-2.American standard reinforcing bar marks.
lines and then pulled out or expanded to form a
diamond shape between each parallel cut. Another
type is square, rather than diamond shaped, as shown
in view B, figure 7-3. Expanded metal is customarily y
used during plastering operations and light reinforcing
concrete construction, such as sidewalks and small
Figure 7-3.Expanded or diamond mesh steel reinforcement.
concrete pads that do not have to bear substantial
weight, such as transformer and air-conditioner pads.
Welded Wire Fabric
Welded wire fabric is fabricated from a series of
wires arranged at right angles to each other and
electrically welded at all intersections. Welded wire
fabric, referred to as WWF within the NCF. has
various uses in reinforced concrete construction. In
building construction, it is most often used for floor
slabs on well-compacted ground. Heavier fabric,
supplied mainly in flat sheets, is often used in walls
and for the primary reinforcement in structural floor
slabs. Additional examples of its use include road and
runway pavements, box culverts, and small canal
Four numbers are use-d to designate the style of
wire mesh; for example, 6 by 6-8 by 8 (sometimes
written 6 x 6 x 8 x 8 or 6 x 6 - W 2.1 x W 2.1). The
first number (in this case, 6) indicates the lengthwise
spacing of the wire in inches; the second number (in
this case, 6) indicates the crosswise spacing of the wire
in inches; the last two numbers (8 by 8) indicate the
size of the wire on the Washburn and Moen gauge.
More recently the last two numbers are a W number
that indicates the size of the cross-sectional area in the
wire in hundredths of an inch. (See table 7-4.) WWF
is currently available within the Navy stock system
using the four-digit system, 6 by 6-8 by 8, as of this
writing, but if procured through civilian sources, the
W system is used.