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definitions index
AAC MASONRY.
Masonry made of autoclaved
aerated concrete (AAC) units, manufactured without internal
reinforcement and bonded together using thin- or thick-bed
mortar.
ADOBE CONSTRUCTION.
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 of wood 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.
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 2,000°F (1093°C) 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 1,000°F (538°C) under normal operating
conditions, but capable of producing combustion gases of
1,400°F (760°C) 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 2,000°F (1093°C) 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. Multi-wythe
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.
GLASS UNIT
MASONRY. 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.
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 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, fm.
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.
STONE MASONRY.
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.
A ceramic 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.
A wall 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).
fAAC
= Specified compressive
strength of AAC masonry, the minimum compressive strength
for a class of AAC masonry as specified in ASTM C 1386,
psi (MPa).
fm
= Specified compressive
strength of masonry at age of 28 days, psi (MPa).
fmi
= 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).
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.
γ
= Reinforcement size factor.
rn
= Ratio of distributed shear reinforcement on plane
perpendicular to plane of Amv.
rmax
= Maximum reinforcement
ratio.
ф
= Strength reduction factor.
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