International Building Code 2102.1
General. The following words and terms shall, for the
purposes of this chapter and as used elsewhere in this code,
have the meanings shown herein.
AAC MASONRY. Masonry made of autoclaved aerated concrete
(AAC) units, manufactured without internal reinforcement
and bonded together using thin- or thick-bed mortar.
ADOBECONSTRUCTION. Construction in which the exterior
load-bearing and nonload-bearing walls and partitions are
of unfired clay masonry units, and floors, roofs and interior
framing are wholly or partly ofwood or other approved materials.
Adobe, stabilized. Unfired clay masonry units to which
admixtures, such as emulsified asphalt, are added during the
manufacturing process to limit the units’ water absorption
so as to increase their durability.
Adobe, unstabilized. Unfired clay masonry units that do
not meet the definition of “Adobe, stabilized.”
ANCHOR. Metal rod, wire or strap that secures masonry to its
structural support.
ARCHITECTURAL TERRA COTTA. Plain or ornamental
hard-burned modified clay units, larger in size than brick, with
glazed or unglazed ceramic finish.
AREA.
Bedded. The area of the surface of a masonry unit that is in
contact with mortar in the plane of the joint.
Gross cross-sectional. The area delineated by the
out-to-out specified dimensions of masonry in the plane
under consideration.
Net cross-sectional. The area of masonry units, grout and
mortar crossed by the plane under consideration based on
out-to-out specified dimensions.
AUTOCLAVED AERATED CONCRETE (AAC).
Low-density cementitious product of calcium silicate hydrates,
whose material specifications are defined in ASTM C 1386.
BED JOINT. The horizontal layer of mortar on which a
masonry unit is laid.
BOND BEAM. A horizontal grouted element within masonry
in which reinforcement is embedded.
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BOND REINFORCING. The adhesion between steel reinforcement
and mortar or grout.
BRICK.
Calcium silicate (sand lime brick). A masonry unit made
of sand and lime.
Clay or shale. A masonry unit made of clay or shale, usually
formed into a rectangular prism while in the plastic state
and burned or fired in a kiln.
Concrete. A masonry unit having the approximate shape of
a rectangular prism and composed of inert aggregate particles
embedded in a hardened cementitious matrix.
BUTTRESS. A projecting part of a masonry wall built integrally
therewith to provide lateral stability.
CAST STONE. A building stone manufactured from portland
cement concrete precast and used as a trim, veneer or facing on
or in buildings or structures.
CELL. A void space having a gross cross-sectional area
greater than 11/2 square inches (967 mm2).
CHIMNEY. A primarily vertical enclosure containing one or
more passageways for conveying flue gases to the outside
atmosphere.
CHIMNEY TYPES.
High-heat appliance type. An approved chimney for
removing the products of combustion from fuel-burning,
high-heat appliances producing combustion gases in excess
of 2,000F (1093C) measured at the appliance flue outlet
(see Section 2113.11.3).
Low-heat appliance type. An approved chimney for
removing the products of combustion from fuel-burning,
low-heat appliances producing combustion gases not in
excess of 1,000F (538C) under normal operating conditions,
but capable of producing combustion gases of
1,400F (760C) during intermittent forces firing for periods
up to 1 hour. Temperatures shall be measured at the
appliance flue outlet.
Masonry type. A field-constructed chimney of solid
masonry units or stones.
Medium-heat appliance type. An approved chimney for
removing the products of combustion from fuel-burning,
medium-heat appliances producing combustion gases not
exceeding 2,000F (1093C) measured at the appliance flue
outlet (see Section 2113.11.2).
CLEANOUT. An opening to the bottom of a grout space of
sufficient size and spacing to allow the removal of debris.
COLLAR JOINT. Vertical longitudinal joint between wythes
of masonry or between masonry and backup construction that
is permitted to be filled with mortar or grout.
COLUMN, MASONRY. An isolated vertical member whose
horizontal dimension measured at right angles to its thickness
does not exceed three times its thickness and whose height is at
least four times its thickness.
COMPOSITE ACTION. Transfer of stress between components
of a member designed so that in resisting loads, the combined
components act together as a single member.
COMPOSITE MASONRY. Multiwythe masonry members
acting with composite action.
COMPRESSIVE STRENGTH OF MASONRY. Maximum
compressive force resisted per unit of net cross-sectional area
of masonry, determined by the testing of masonry prisms or a
function of individual masonry units, mortar and grout.
CONNECTOR. A mechanical device for securing two or
more pieces, parts or members together, including anchors,
wall ties and fasteners.
COVER. Distance between surface of reinforcing bar and
edge of member.
DIAPHRAGM. A roof or floor system designed to transmit
lateral forces to shear walls or other lateral-load-resisting elements.
DIMENSIONS.
Actual. The measured dimension of a masonry unit or element.
Nominal. The specified dimension plus an allowance for
the joints with which the units are to be laid. Thickness is
given first, followed by height and then length.
Specified. The dimensions specified for the manufacture or
construction of masonry, masonry units, joints or any other
component of a structure.
EFFECTIVE HEIGHT. For braced members, the effective
height is the clear height between lateral supports and is used
for calculating the slenderness ratio. The effective height for
unbraced members is calculated in accordance with engineering
mechanics.
FIREPLACE. A hearth and fire chamber or similar prepared
place in which a fire may be made and which is built in conjunction
with a chimney.
FIREPLACE THROAT. The opening between the top of the
firebox and the smoke chamber.
FOUNDATION PIER. An isolated vertical foundation member
whose horizontal dimension measured at right angles to its
thickness does not exceed three times its thickness and whose
height is equal to or less than four times its thickness.
GLASSUNITMASONRY. Masonry composed of glass units
bonded by mortar.
GROUTED MASONRY.
Grouted hollow-unit masonry. That form of grouted
masonry construction in which certain designated cells of
hollow units are continuously filled with grout.
Grouted multiwythe masonry. That form of grouted
masonry construction in which the space between the
wythes is solidly or periodically filled with grout.
HEAD JOINT. Vertical mortar joint placed between masonry
units within the wythe at the time the masonry units are laid.
HEADER (Bonder). A masonry unit that connects two or
more adjacent wythes of masonry.
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HEIGHT,WALLS. The vertical distance from the foundation
wall or other immediate support of such wall to the top of the
wall.
MASONRY. A built-up construction or combination of building
units or materials of clay, shale, concrete, glass, gypsum,
stone or other approved units bonded together with or without
mortar or grout or other accepted methods of joining.
Ashlar masonry. Masonry composed of various-sized rectangular
units having sawed, dressed or squared bed surfaces,
properly bonded and laid in mortar.
Coursed ashlar. Ashlar masonry laid in courses of stone of
equal height for each course, although different courses
shall be permitted to be of varying height.
Glass unit masonry. Masonry composed of glass units
bonded by mortar.
Plain masonry. Masonry in which the tensile resistance of
the masonry is taken into consideration and the effects of
stresses in reinforcement are neglected.
Random ashlar. Ashlar masonry laid in courses of stone set
without continuous joints and laid up without drawn patterns.
When composed of material cut into modular heights,
discontinuous but aligned horizontal joints are discernible.
Reinforced masonry. Masonry construction in which reinforcement
acting in conjunction with the masonry is used to
resist forces.
Solid masonry. Masonry consisting of solid masonry units
laid contiguously with the joints between the units filled
with mortar.
Unreinforced (plain) masonry. Masonry in which the tensile
resistance of masonry is taken into consideration and
the resistance of the reinforcing steel, if present, is
neglected.
MASONRY UNIT. Brick, tile, stone, glass block or concrete
block conforming to the requirements specified in Section
2103.
Clay. A building unit larger in size than a brick, composed
of burned clay, shale, fired clay or mixtures thereof.
Concrete. A building unit or block larger in size than 12
inches by 4 inches by 4 inches (305 mm by 102 mm by 102
mm) made of cement and suitable aggregates.
Hollow. A masonry unit whose net cross-sectional area in
any plane parallel to the load-bearing surface is less than 75
percent of its gross cross-sectional area measured in the
same plane.
Solid. A masonry unit whose net cross-sectional area in
every plane parallel to the load-bearing surface is 75 percent
or more of its gross cross-sectional area measured in the
same plane.
MEAN DAILY TEMPERATURE. The average daily temperature
of temperature extremes predicted by a local weather
bureau for the next 24 hours.
MORTAR. A plastic mixture of approved cementitious materials,
fine aggregates and water used to bond masonry or other
structural units.
MORTAR, SURFACE-BONDING. A mixture to bond concrete
masonry units that contains hydraulic cement, glass fiber
reinforcement with or without inorganic fillers or organic modifiers
and water.
PLASTIC HINGE. The zone in a structural member in which
the yield moment is anticipated to be exceeded under loading
combinations that include earthquakes.
PRESTRESSED MASONRY. Masonry in which internal
stresses have been introduced to counteract potential tensile
stresses in masonry resulting from applied loads.
PRISM. An assemblage of masonry units and mortar with or
without grout used as a test specimen for determining properties
of the masonry.
RUBBLE MASONRY. Masonry composed of roughly
shaped stones.
Coursed rubble. Masonry composed of roughly shaped
stones fitting approximately on level beds and well bonded.
Random rubble. Masonry composed of roughly shaped
stones laid without regularity of coursing but well bonded
and fitted together to form well-divided joints.
Rough or ordinary rubble. Masonry composed of
unsquared field stones laid without regularity of coursing
but well bonded.
RUNNING BOND. The placement of masonry units such that
head joints in successive courses are horizontally offset at least
one-quarter the unit length.
SHEAR WALL.
Detailed plain masonry shear wall. A masonry shear wall
designed to resist lateral forces neglecting stresses in reinforcement,
and designed in accordance with Section
2106.1.1.
Intermediate prestressed masonry shear wall. A prestressed
masonry shear wall designed to resist lateral forces
considering stresses in reinforcement, and designed in
accordance with Section 2106.1.1.2.
Intermediate reinforced masonry shear wall. A masonry
shear wall designed to resist lateral forces considering
stresses in reinforcement, and designed in accordance with
Section 2106.1.1.
Ordinary plain masonry shear wall. A masonry shear
wall designed to resist lateral forces neglecting stresses in
reinforcement, and designed in accordance with Section
2106.1.1.
Ordinary plain prestressed masonry shear wall. A prestressed
masonry shear wall designed to resist lateral forces
considering stresses in reinforcement, and designed in
accordance with Section 2106.1.1.1.
Ordinary reinforced masonry shear wall. A masonry
shear wall designed to resist lateral forces considering
stresses in reinforcement, and designed in accordance with
Section 2106.1.1.
Special prestressed masonry shear wall. A prestressed
masonry shear wall designed to resist lateral forces considering
stresses in reinforcement and designed in accordance
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with Section 2106.1.1.3 except that only grouted, laterally
restrained tendons are used.
Special reinforced masonry shear wall. A masonry shear
wall designed to resist lateral forces considering stresses in
reinforcement, and designed in accordance with Section
2106.1.1.
SHELL. The outer portion of a hollow masonry unit as placed
in masonry.
SPECIFIED. Required by construction documents.
SPECIFIED COMPRESSIVE STRENGTH OF
MASONRY, f m. Minimum compressive strength, expressed
as force per unit of net cross-sectional area, required of the
masonry used in construction by the construction documents,
and upon which the project design is based. Whenever the
quantity f m is under the radical sign, the square root of numerical
value only is intended and the result has units of pounds per
square inch (psi) (MPa).
STACK BOND. The placement of masonry units in a bond
pattern is such that head joints in successive courses are vertically
aligned. For the purpose of this code, requirements for
stack bond shall apply to masonry laid in other than running
bond.
STONEMASONRY. Masonry composed of field, quarried or
cast stone units bonded by mortar.
Ashlar stone masonry. Stone masonry composed of rectangular
units having sawed, dressed or squared bed surfaces
and bonded by mortar.
Rubble stone masonry. Stone masonry composed of irregular-
shaped units bonded by mortar.
STRENGTH.
Design strength. Nominal strength multiplied by a strength
reduction factor.
Nominal strength. Strength of a member or cross section
calculated in accordance with these provisions before application
of any strength-reduction factors.
Required strength. Strength of a member or cross section
required to resist factored loads.
THIN-BED MORTAR. Mortar for use in construction of
AAC unit masonry with joints 0.06 inch (1.5 mm) or less.
TIE, LATERAL. Loop of reinforcing bar or wire enclosing
longitudinal reinforcement.
TIE, WALL. A connector that connects wythes of masonry
walls together.
TILE.Aceramic surface unit, usually relatively thin in relation
to facial area, made from clay or a mixture of clay or other
ceramic materials, called the body of the tile, having either a
“glazed” or “unglazed” face and fired above red heat in the
course of manufacture to a temperature sufficiently high
enough to produce specific physical properties and characteristics.
TILE, STRUCTURAL CLAY. A hollow masonry unit composed
of burned clay, shale, fire clay or mixture thereof, and
having parallel cells.
WALL. A vertical element with a horizontal length-to-thickness
ratio greater than three, used to enclose space.
Cavity wall.Awall built of masonry units or of concrete, or
a combination of these materials, arranged to provide an airspace
within the wall, and in which the inner and outer parts
of the wall are tied together with metal ties.
Composite wall. A wall built of a combination of two or
more masonry units bonded together, one forming the
backup and the other forming the facing elements.
Dry-stacked, surface-bonded walls. A wall built of concrete
masonry units where the units are stacked dry, without
mortar on the bed or head joints, and where both sides of the
wall are coated with a surface-bonding mortar.
Masonry-bonded hollow wall. A wall built of masonry
units so arranged as to provide an airspace within the wall,
and in which the facing and backing of the wall are bonded
together with masonry units.
Parapet wall. The part of any wall entirely above the roof
line.
WEB. An interior solid portion of a hollow masonry unit as
placed in masonry.
WYTHE. Each continuous, vertical section of a wall, one
masonry unit in thickness.
NOTATIONS.
An = Net cross-sectional area of masonry, square inches
(mm2).
b = Effective width of rectangular member or width of
flange for T and I sections, inches (mm).
db = Diameter of reinforcement, inches (mm).
Fs =Allowable tensile or compressive stress in reinforcement,
psi (MPa).
fr = Modulus of rupture, psi (MPa).
fy = Specified yield stress of the reinforcement or the
anchor bolt, psi (MPa).
f_
AAC = Specified compressive strength of AAC masonry, the
minimum compressive strength for a class of AAC
masonry as specified in ASTM C 1386, psi (MPa).
f m = Specified compressive strength of masonry at age of 28
days, psi (MPa).
f mi = Specified compressive strength of masonry at the time
of prestress transfer, psi (MPa).
K = The lesser of the masonry cover, clear spacing between
adjacent reinforcement, or five times db, inches (mm).
Ls = Distance between supports, inches (mm).
Lw = Length of wall, inches (mm).
ld = Required development length or lap length of reinforcement,
inches (mm).
lde = Embedment length of reinforcement, inches (mm).
Pw = Weight of wall tributary to section under consideration,
pounds (N).
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t = Specified wall thickness dimension or the least lateral
dimension of a column, inches (mm).
Vn = Nominal shear strength, pounds (N).
Vu = Required shear strength due to factored loads, pounds
(N).
W = Wind load, or related internal moments in forces.
= Reinforcement size factor.
?n = Ratio of distributed shear reinforcement on plane perpendicular
to plane of Amv.
max = Maximum reinforcement ratio.
??= Strength reduction factor.