Aci 315-99 supersedes aci 315-92 and became effective August 31, 1999

5.2—Types of bar supports
5.2.1 Wire bar supports—Descriptions of wire bar sup-
ports and examples of their usage are available as industry
recommendations in the CRSI Manual of Standard Practice,
which is revised periodically to reflect the latest practice.
Caution: When multiple layers of unusually heavy reinforc-
ing bars are to be supported on wire bar supports, the number
of wire bar supports may need to be increased to prevent pen-
etration of support legs into the form material, especially
where the surface is exposed to view or corrosion.
5.2.2 Precast concrete bar supports—Descriptions of
commonly used types and sizes are available in the CRSI
Manual of Standard Practice. Requirements for texture and
color to suit job conditions should be added if necessary.
Caution: If the finished surface will be subjected to sand-
blasting, bush-hammering, or chemical removal of external
mortar, the different texture of the exposed precast blocks
(unless part of a planned pattern) may be objectionable.
5.2.3 Other types of bar supports—CRSI’s Manual of
Standard Practice contains descriptions of one other type of
bar supports, all-plastic bar supports. See the supporting ref-
erence data section for more information.
5.3—Side form spacers and beam bolsters
All reinforcing steel must be firmly held in place before
and during casting of concrete by means of precast concrete
blocks, metallic or plastic supports, spacer bars, wires, or oth-
er devices adequate to ensure against displacement during
construction and to keep the reinforcing steel at the proper
distance from the forms. Selection of the type of spacer tra-
ditionally has been the responsibility of the contractor. De-
tailing of side form spacers is not a standard requirement and
is performed only when specifically required by the contract
documents. The reinforcing bar placing drawings need only
show, and the fabricator will only be responsible to supply,
those side form spacers that are equal to the standard bar sup-
ports referred to in 
Section 5.2
.
Beam bolsters are typically placed transversely to the
beam. Beam bolsters placed longitudinally with the beam are
supplied only upon special arrangements between the con-
tractor and the supplier, if approved by the A/E.