Masonry Magazine October 1993 Page. 25
Technical Notes on Brick Construction
Brick Institute of America 11490 Commerce Park Drive, Reston, Virginia 22091
3B
BRICK MASONRY SECTION PROPERTIES
**Abstract:** This *Technical Notes* is a design aid for the *Building Code Requirements for Masonry Structures* (ACI 530/ASCE 5/TMS 402-92) and *Specifications for Masonry Structures* (ACI 530.1/ASCE 6/TMS 602-92). Section properties of brick masonry units, steel reinforcement and brick masonry assemblages are given to simplify the design process. Section properties are used to calculate stresses and to determine the allowable stresses given in the ACI 530/ASCE 5/TMS 402-92 Code.
**Key Words:** brick, dimensions, section properties, steel reinforcement.
Brick Institute of America
May 1993
INTRODUCTION
An assemblage's geometry determines its ability to resist loads. Section properties are properties of a masonry assemblage which are based solely on its geometry. Section properties are used in design and analysis of brick masonry structural elements. Section properties are used to determine allowable stresses which may be applied to brick masonry elements, as well as to calculate an element's stress under applied loads. Because brick is a small building unit, it may be used to construct assemblages of nearly any configuration. While this is a benefit of construction with brick masonry, it can make design tedious because each masonry assemblage will have unique section properties. To simplify the design process, this *Technical Notes* presents the section properties of brick units, steel reinforcement and typical brick masonry assemblages. The section properties are based on specified dimensions of the units and assemblages.
This *Technical Notes* is a design aid for the *Building Code Requirements for Masonry Structures* (ACI 530/ASCE 5/TMS 402-92) and the *Specifications for Masonry Structures* (ACI 530.1/ASCE 6/TMS 602-92). These documents, which are promulgated by the Masonry Standards Joint Committee (MSJC), will be referred to as the MSJC Code and the MSJC Specifications, respectively. References are made to the MSJC Code and Specifications to indicate where each section property applies. Other *Technical Notes* in this series provide an overview of the MSJC Code and Specifications and material properties of brick masonry.
NOTATION
Following are notations used in the text, figure and tables in this *Technical Notes*. Where applicable, notations are the same as used in the MSJC Code and Specifications.
Aₘ Net cross-sectional area of masonry, in.² (mm²)
Aₛ Area of steel, in.² (mm²)
b Width of section, in. (mm)
bғₗₐₙgₑ Width of flange, in. (mm)
bᵥₑb Width of web, in. (mm)
d Distance from extreme compression fiber to the centroid of tension reinforcement, in. (mm)
Eₘ Elastic modulus of masonry, psi (MPa)
Eₛ Elastic modulus of steel, psi (MPa)
I Moment of inertia, in.⁴ (m⁴)
j Ratio of distance between centroid of flexural compressive forces and centroid of tensile forces to depth
k Ratio of distance between compression face and neutral axis to distance between compression face and centroid of tensile forces
n Elastic moduli ratio, Eₛ/Eₘ
Q First moment about the neutral axis of a section of that portion of the cross section lying between the neutral axis and extreme fiber, in.³ (m³)
r Radius of gyration, in. (mm)
S Section modulus, in.³ (m³)
SECTION PROPERTIES OF CONSTITUENT MATERIALS
The constituent materials of units, mortar, grout and reinforcement combine to form brick masonry assemblages. The section properties of each constituent material may be required in the design process. The section properties of clay and shale masonry units are the basis for the section properties of the total brick masonry assemblage. The section properties of steel reinforcement are used to determine the size and spacing of
MASONRY-SEPTEMBER/OCTOBER, 1993 25
| MASONRY
4d B