Source: CONCRETE CONSTRUCTION MAGAZINE
Publication date: November 1, 2005
Â Â Â Â Â Â Â Â Â Setting anchor bolts can be as easy as cutting out a plywood jig to hold the bolts and positioning the assembly just above a slab during concrete placement. More precision requires much more elaborate methods. Brian Long, a superintendent for Lindblad Construction, Joliet, Ill., specializes in highly accurate anchor bolt placements. His company’s goal is to do the job right so that remedial action isn’t needed after concrete is placed.
Â Â Â Â Â Â Â Â Â Long says that the length of an anchor bolt is important, too. Shorter bolts are much easier to secure than longer ones. In either case, before work starts in the field, Lindblad constructs CAD shop drawings for each of the templates needed for a project. Its steel fabricator uses the CAD files to guide the machines in the production of extremely accurate templates from Â¼-inch-thick steel plate. The templates hold the anchor bolts, and usually two or three template plates hold each anchor assembly in position.
Â Â Â Â Â Â Â Â Â On the jobsite, concrete â€œmud matsâ€ are first cast under the slab. Layout on the mud mats locates the position for the templates. Long says his company hires surveyors who use theodolites to locate the centerlines in both directions for the templates. With the centerlines marked on the mud mats, workers can use tape measures to mark out the template locations. After locations are marked, rigid steel frames are erected and bolted into the mud mats to hold the templates at the proper position and elevation. Depending on the size and complexity of a template, either angle-iron or universal strut is used to build the frame. The final step is checking. By setting lines at the top of a slab on the template center marks, workers can easily check to see that the positioning is right.
Â Â Â Â Â Â Â Â Â Even though anchor bolts are very secure when concrete is being placed, Long says the placing crew is told: â€œDon’t touch the anchor bolts.â€ There is constant monitoring during placement. Long adds that it’s helpful to have the same concrete crew for each placement. (End Article).
Anchor Bolt Source provides high-quality, nonstandard anchor bolts and construction fasteners. For more information please visit the Anchor Bolt Source website.