Technical-Resources-for-Concrete-Contractors
Technical-Resources-for-Concrete-Contractors
Technical-Resources-for-Concrete-Contractors
Technical-Resources-for-Concrete-Contractors
Technical-Resources-for-Concrete-Contractors
Technical-Resources-for-Concrete-Contractors

Location of Rolled Welded-Wire Fabric in Concrete

ASCC Position Statement #2

Some specifications require concrete contractors to use rolled welded-wire fabric for reinforcement in slabs-on-grade, topping slabs,
and composite slabs on metal decking. The risk associated with using rolled welded-wire fabric is well known. It’s difficult to ensure that the wire is placed in the specified position and remains there during concrete placement.

Rolled welded-wire fabric is available only in W1.4 to W4 wire sizes and varies in width from 5 to 8 ft (1.5 to 2.4 m). Lengths vary with application and convenience of handling and shipping. Rolls are straightened before use, but the resulting shape is a wavy profile.

ACI 302.1R-96, “Guide for Concrete Floor and Slab Construction,” recommends that weldedwire fabric not be laid on the ground and “pulled up” after the concrete is placed nor “walked in” after placing the concrete. ACI 302 recommends using supports or support bars to maintain the proper elevation, but states that the support bars should be spaced close enough so the weldedwire fabric cannot be forced out of location by foot traffic. The cost of support bars for W1.4 and W4 wire sizes can be more than the cost of the welded-wire fabric, and the cross-sectional area of such support bars is about equal to the area provided by the welded-wire fabric. This argues for using bars instead of fabric.

Want to learn more? Download the full Position Statement! 

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