Copyright Goodheart-Willcox Co., Inc. 112 Section 3 Specifications and Materials The “D” fabric has deformations along the wire to better develop anchorage in the concrete. Previously, the fabric was specified by gage number, and some drawings still use this system. Welded wire fabric is further designated by numbers. An example is 6×8–W8.0×W4.0. The first number (6) gives × the spacing of the longitudinal wire in inches. The second number (8) gives the spacing of the transverse wire in inches. The first letter-number combination (W8.0) gives the type and size of the longitudinal wire. The second combination (W4.0) gives information on the transverse wire. In the example given, the longitudinal wires are 6″ apart. The transverse wires are 8″ apart. The longitu- ″ dinal wire is smooth and has a cross-sectional area of 0.08 in2. The transverse wire is also smooth with an area of 0.04 in2. Figure 7-8 lists some of the common stock styles of welded wire fabric. Figure 7-9 shows how mesh is placed in a concrete slab. Division 04—Masonry Masonry structures are made from a number of smaller units held together with a bonding material known as mortar. Masonry units are manufactured as brick, r r concrete block, stone, and clay tile. Mortar is a cementi- r tious material that bonds the individual units together. Almost all masonry construction must be strength- ened with reinforcing materials. Like concrete, masonry has good compressive strength and poor tensile strength. Reinforcing bars are round in shape, with surface projections (called deformations) formed in the rolling process to strengthen bonding with the concrete. Bars are placed after the forms are constructed, Figure 7-6. The concrete is then cast around the bars. Sheets of wire mesh are also used for reinforcement. Welded wire fabric (WWF) is a prefabricated material used to reinforce concrete slabs, floors, and pipe. It consists of a mesh of steel wires welded together, Figure 7-7. It is available in sheets and rolls and many 7 7 wire sizes. There are two types of welded wire fabric: smooth (or plain), designated by a W and W W deformed, designated D. Dan Dorfmueller Figure 7-6. This grid of reinforcing steel bars will add strength to the completed concrete foundation and structure it supports above. Length Overall width Width Transverse wire Longitudinal wire End overhang may differ. The sum of the two end overhangs, however, should equal the transverse wire spacing. Side overhangs may be varied as required and do not need to be equal. Overhang lengths limited only by overall sheet width. Wire Reinforcement Institute Figure 7-7. Nomenclature used for welded wire fabric.