Stirrups - These are shaped rebar that hold the lateral reinforcement in a certain configuration, often called a cage. They create a framework that keeps these larger bars in position, and may be round, square, rectangular, or even complex combinations of shapes. [1] X Research source Dowels - These are usually L shapes, or straight lengths of rebar with a ninety degree bend on one end. Corner bars - These are also L shapes, with each side of the ell the same length. Offset bends - These range from a simple Z shape to complex angles, used in reinforcing concrete walkway steps and steps (changes in elevation) in concrete footings. Hairpins - These are U shaped rebar that are often used to interlock two or more individual mats of rebar to give lateral strength to the concrete casting. Candy canes - As the name implies, these are straight lengths of rebar with a U shaped bend on one or both ends, again to interlock two or more parallel reinforcing mats.
Figure 8 ties - These are made by pulling the wire around the rear (from the rodbuster) bar, diagonally across the front bar, back around the rear bar, diagonally in the opposite direction across the front bar, and then twisting back around the beginning wire. You then cut the wire feeding off the reel, and bend the cut ends back towards the tie so no sharp ends project from the tie. These ties will help hold perpendicular bars tightly together while helping to prevent them from racking, or moving diagonally. Saddle ties - Similar to the figure 8 tie, you begin by passing the wire feeding from your reel behind the rear bar, then across the front bar staying parallel to the bar. You then pass it behind the rear bar again, back around the front bar on the opposite side. You now twist the ends together, cut the feed wire, and bend the cut ends back. This tie is often used when tying rebar for walls or other vertical application where the rodbuster will actually climb on the rebar framework to access higher portions of the wall. The figure 8 and saddle tie can often be interchanged, however, technically speaking, there are advantages to each one in certain circumstances. Combinations of figure 8 and saddle ties with additional wraps around vertical rebars can be used to increase the hold of the tie so bars cannot slip downward when weight is applied to them or the plastic concrete is dropped into the form.
Block dowels - When placing a concrete foundation which will have concrete masonry units (block) erected on it, you will usually find the plans require installing block dowels, or vertical rebar to reinforce cells at a required spacing to give the subsequent block wall sufficient strength to withstand conditions to which it will be exposed, or to help it support loads it will carry as an overall part of the structure you are building. These bars are tied to the foundation rebar (footing bars) in a location that will place them in the center of individual block cells. For them to be placed correctly, you will need to establish the wall line, then determine the spacing of these cells. If your layout begins at a corner, using 8X16 inch regular block, you can place the first dowel 4 inches (10. 2 cm) inside the outside wall line, 4 inches (10. 2 cm) from the corner, then space additional bars at their required distances in multiples of 8 inches (20. 3 cm). For example, at 16, 24, or 32 inch centers. This is known as blockwork spacing. Bulkhead dowels - In instances where a footing will not be completed in a single concrete placement, you will need to dowel out of the bulkhead form so the next placement will be structurally tied to the latter one. Make sure the dowels extend far enough that the lateral reinforcement will overlap enough to maintain the strength of the rods used. Typically, rebar lap is calculated in bar diameters. An example would be the number 5 rebar mentioned earlier. It has a diameter of 5/8 of an inch, and the required lap might be 40 bar diameters. Multiplying the diameter 5/8 by 40, you will get 200⁄8 or 25 inches (63. 5 or 63. 5 cm). Note that in structural concrete, other types of imbeds and inserts may be required. Place rebar in such a manner as to allow installation of anchor bolts, sleeves, embedded weld plates, inserts, or other items in their respective correct locations without interference. In general terms, these items require more precise positioning, so offsetting one or two rebars may be required.
