In-Plane Shear Resistance of Insulating Concrete Form Walls (April 2001, 41 p.)
The efficient use of shear walls in residential construction subjected to wind and seismic loading
is of great interest to designers and builders of homes in high hazard areas of the United States.
Shear walls are the primary lateral force resisting system in residential construction. There has
been considerable research aimed at optimizing the design of light-framed shear walls (wood and
cold-formed steel) in recent years. For relatively new types of wall systems, such as Insulating
Concrete Form (ICF) wall construction, the technical information available is limited. There is a
need to confirm or improve the use of traditional concrete shear wall design methods particularly
in the context of ICF systems and residential construction practices. Thus, inefficiencies that
result in conservative (uneconomical) or unconservative (unsafe) applications may be avoided.
A research program was initiated at the NAHB Research Center to study the structural
performance of ICF walls when subjected to in-plane shear loading. An experimental study was
designed to determine the influence of the following factors on the in-plane shear strength of ICF
walls: (1) height-to-length aspect ratio of shear wall segments, (2) openings for windows and
doors, and (3) the current minimal reinforcement details provided by the Prescriptive Method for
Insulating Concrete Forms in Residential Construction (Prescriptive Method) [1]. The main goal
of this study was to confirm and improve methods of evaluating the in-plane shear capacity of ICF
walls. This information is intended to improve the shear wall design and construction guidance
found in the Prescriptive Method [1] and the International Residential Code [2].
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