25 January 2005
MASONRY DESIGN REQUIREMENTS
This chapter provides the specific requirements for designing a masonry
building to resist progressive collapse.
For composite construction, such as masonry load-bearing walls with wood
floor and roof systems, the application of both the requirements of this chapter and
those provided for the other material (e.g., wood in Chapter 7) are required. The floor
system and roof system would be required to meet the internal tie requirements of
Chapter 7, while the masonry walls would be required to meet the tie (vertical,
peripheral, and wall) requirements or AP requirements of this chapter.
MATERIAL PROPERTIES FOR MASONRY.
All over strength factors for masonry are equal to 1.0.
MASONRY TIE FORCE REQUIREMENTS.
Representative connection details for developing tie forces in masonry
construction are presented in Appendix E.
Provide peripheral, internal, and column or wall ties at each floor level and at
roof level, but where the roof is of lightweight construction, no such ties need be
provided at that level. Horizontal ties may be provided by structural members or by
reinforcement that is provided for other purposes.
Strength Reduction Factor Φ for Masonry Tie Forces
Use the strength reduction factors Φ for development and splices of
reinforcement and for anchor bolts as specified in Section 3-1 of Building Code
Requirements for Masonry Structures from ACI (ACI 530-02).
Proportioning of Ties.
Reinforcement that is provided for other purposes, such as flexure or shear,
may be regarded as forming part or whole of the required ties.
Splices in longitudinal reinforcing bars that provide tie forces must be lapped,
welded or mechanically joined, per Section 3-2. Do not locate splices near connections
or mid-span. Tie reinforcing bars that provide tie forces at right angles to other