The application of welded wire fabric that first comes to mind for most engineers and contractors is the reinforcement of nonstructural slabs on grade with rolls of "building fabric." This is usually light mesh designated 6x6 W1.4xW1.4. The first pair of numbers indicates the spacing of the wires in inches. The second pair gives the size of the respective wires in cross-sectional area.
The amount of wire depends on the load on the slab, the slab thickness and the spacing of the joints. The Portland Cement Association in the publication "Concrete Floors on Ground" provides a selection chart for distributed steel that is a good guide to the designer. When longer joint spacing is desired to reduce the number of joints more steel is required. Concrete pipe manufacturers depend on welded wire fabric, either smooth or deformed wire, to meet the criteria of the industry's ASTM standards. Its ability to delay the concrete from cracking under test loads has made it the selected reinforcement for concrete pipe of all sizes and shapes.
For concrete streets, highways and runways welded wire fabric is used in large sheets. This paving may take the form of jointed reinforced concrete pavement or continuously reinforced concrete. In jointed slabs, the reinforcement is selected based on the traditional subgrade drag theory and the amount of steel will vary based on the yield strength of the steel, the thickness of the slab, the spacing of the joints and the friction of the subgrade. Sheets as large as 13 feet by 40 feet have been used in paving projects. The amount of reinforcement in jointed slabs is relatively low, usually in the range of 0.05 to 0.20 percent. The capability of making wires at various sizes and spacings gives the designer a means to provide the exact area of steel per foot required and thus save tonnage on many high-rise projects. Another tonnage saver is the use of a higher yield strength when designing in welded wire fabric.
