masonry Flashcards
A ____ is formed by combining masonry units, such as stone, blocks, or brick with mortar.
masonry structure
_____ is one of the oldest construction materials.
masonry
_____ are a popular construction material throughout the world and competes favorably with other materials, such as wood, steel, and concrete for certain applications.
masonry units
Masonry units can be classified as: ____, ___, ____, _____, ____
concrete masonry units, clay bricks, structural clay tiles, glass blocks, stone
____ can be either solid or hollow, but clay bricks, glass blocks, and stone are typically solid.
concrete masonry
_____ are hollow units that are larger than clay bricks and are used for structural and nonstructural masonry applications, such as partition walls and filler panels.
structural clay tiles
Solid concrete units are commonly called _____.
concrete bricks
Hollow units are known as _____.
concrete blocks, hollow blocks, cinder blocks
Hollow units have a net cross-sectional area in every plane parallel to the bearing surface less than ____ of the gross cross-sectional area in the same plane.
75%
Concrete masonry units are manufactured in three classes, based on their density: ____
lightweight units, medium-weight units, normal-weight units
Well-graded sand, gravel, and crushed stone are used to manufacture _____.
normal-weight units
Lightweight aggregates such as pumice, scoria cinders, expanded clay, and expanded shale are used to manufacture _____.
lightweight units
_____ have higher thermal and fire resistance properties and lower sound resistance than normal weights.
lightweight units
_____ are manufactured using a relatively dry (zero-slump) concrete mixture consisting of portland cement, aggregates, water, and admixtures.
concrete masonry
_____ is usually used to manufacture concrete masonry units.
type I
____ is sometimes used to reduce the curing time.
type III
_____ is sometimes used to increase the resistance of the masonry structure to freeze and thaw effects and improve workability, compaction, and molding characteristics of the units during manufacturing.
air-entrained concrete
Concrete masonry units can be classified as ______ and ____.
load bearing (ASTM C90), non-load bearing (ASTM C129)
Load-bearing units must satisfy a ________ minimum compressive strength requirement than non-loading bearing units.
higher
The ____ of the individual concrete masonry units is determined by capping the unit and applying load in the direction of the height of the unit until failure (ASTM C140).
compressive strength
The _____ is calculated by dividing the load at failure by the gross cross-sectional area of the unit.
gross area compressive strength
The _____ is calculated by dividing the load at failure by the net cross-sectional area.
net area compressive strength
The _____ is calculated by dividing the net volume of the unit by its average height.
net cross-sectional area
The ____ is determined using the water displacement method according to ASTM C140.
net volume
The amount of water absorption of concrete masonry units is controlled by ASTM standards to reduce the effect of weathering and limit the amount of shrinkage due to moisture loss after construction.
ASTM C90
The absorption of concrete masonry units is determined by immersing the units in water for 24 hours.
ASTM C140
Concrete masonry units are specified by their ______.
nominal dimensions
The _____ is greater than its specified (or modular) dimensions by the thickness of the mortar joint, usually 10 mm (3/8 in.)
nominal dimension
____ are available in nominal widths of 100, 150, 200, 250, and 300 mm (4, 6, 8, 10, and 12 in.), heights of 100 and 200 mm (4 and 8 in.), and lengths of 300, 400, and 600 mm (12, 16, and 24 in.).
load-bearing masonry units
Solid concrete masonry units (concrete bricks) are manufactured in two types based on their exposure properties: _____ and ______.
concrete building bricks (ASTM C55), concrete facing bricks (ASTM C1634)
The ____ are manufactured for general use in nonfacing, utilitarian applications.
concrete building bricks
____ are typically used in applications where one or more faces of the unit is intended to be exposed.
concrete facing bricks
The maximum allowable water absorption of the concrete facing bricks is ____ than that of the concrete building bricks.
less
The minimum net area compressive strength of the concrete facing bricks is ____ than that of the concrete building bricks.
higher
_____ are small, rectangular blocks made of fired clay.
clay bricks
_____ are manufactured by grinding or crushing the clay in mills and mixing it with water to make it plastic.
bricks
Clay bricks have an average density of ____.
2 Mg/m^3 (125 pcf)
_____ are used for different purposes, including building, facing aesthetics, floor making, and paving.
clay bricks
____ are used as a structural material and are typically strong and durable.
building bricks (common bricks)
____ are used for facing and aesthetic purposes and are available in different sizes, colors, and textures.
facing bricks
_____ are used on finished floor surfaces and are generally smooth and dense, with high resistance to abrasion.
floor bricks
_____ are used as a paving material for roads, sidewalks, patios, driveways, and interior floors.
paving bricks
_____ means glazed to render it impervious to water and highly resistant to corrosion.
vitrified
____ is one of the important properties that determine the durability of bricks.
absorption
_____ absorptive bricks can cause efflorescence and other problems in the masonry.
highly
____ are very durable and fire resistant and require very little maintenance. They have moderate insulating properties, which make brick houses cooler in summer and warmer in winter.
clay bricks
____ are also noncombustible and poor conductors.
clay bricks
The ____ of clay bricks is an important mechanical property that controls their load-carrying capacity and durability.
compressive strength
The ____ of clay bricks is dependent on the composition of the clay, method of brick manufacturing, and the degree of firing.
compressive strength
The ____ is determined by capping and testing a half unit “flatwise” (load applied in the direction of the height of the unit) and is calculated by dividing the at failure by the cross-sectional area (ASTM C67).
compressive strength
Other mechanical properties of bricks include ___
modulus of rupture, tensile strength, modulus of elasticity
Most clay bricks have modulus of rupture between ______.
3.5 and 26.2 MPa (500 anf 3800 psi)
The tensile strength is typically between _____ of the modulus of rupture.
30% to 49%
The modulus of elasticity ranges between ____.
10.3 and 34.5 GPa (1.5x10^6 ang 5x10^6 psi)
Clay building bricks are graded according to properties related to ____ and _____, such as compressive strength, water absorption, and saturation coefficient (ASTM C62).
durability, resistance to weathering
Three available grades of clay building bricks: ____
severe weathering (SW), moderate weathering (MW), negligible weathering (NW)
Grade ____ bricks are intended for use in areas subjected to frost action, especially at or below ground level.
SW
Grade ____ bricks are recommended for use in areas with no frost action and in dry locations, even where subfreezing temperatures are expected.
NW
______ are manufactured in two durability grades for severe weathering (SW) and moderate weathering (MW).
facing clay bricks (ASTM C216)
Each durability grade is manufactured in three appearance types: _____
face brick standard (FBS), face brick extra (FBX), face brick architecture (FBA)
Type ____ bricks are used for general exposed masonry construction.
FBS
Type ____ are used for general exterior and interior masonry construction, where a high degree of precision and a low permissible variation in size are required.
FBX
The ____ type bricks are manufactured to produce characteristic architectural effects resulting from nonuniformity in size and texture of the individual units.
FBA
Similar to concrete masonry units, clay bricks are designated by their _____.
nominal dimensions
The ____ of the brick is greater than its specified (or modular) dimension by the thickness of the mortar joint.
nominal dimension
The ____ of the brick depends on the nominal size and the amount of shrinking that occurs during the firing process, which ranges from 4% to 15%.
actual size
____ are specified by their nominal width times nominal height times nominal length.
clay bricks
Bricks can be classified as either ______.
modular or nonmodular
_____ bricks have widths and lengths of multiples of 100 mm (4 in.).
modular
_____ is a mixture of cementitious material, aggregates, and water.
mortar
Mortar can be classified as ____, ____, or ______.
cement-lime mortar, cement mortar, masonry cement mortar
Mortar is used for the following functions: ____
- bonding masonry units together, either non-reinforced or reinforced
- serving as a seating material for the units
- leveling and seating the units
- providing aesthetic quality of the structure
Mortar is manufactured in four types: _____
M, S, N, O
____ also needs to satisfy either proportion and specifications or property specifications (ASTM C270).
mortar
The ____ specify the ingredient quantities.
proportion specifications
The _____ specify the compressive strength, water retention, air content, and the aggregate ratio.
property specifications
In the ____ evaluation, the compressive strength of mortar is tested using 50-mm (2-inch) cubes according to ASTM C109.
laboratory
The minimum average compressive strengths of types M, S, N, and O at 28 days are ______ MPa.
17.2, 12.4, 5.2, 2.4
The ____ evaluation involved the preparation of one or more trial batches before construction. These trial batches are sampled and used in establishing the plastic and hardened properties of the mixtures (ASTM C780).
field
It should be noted, however, that ___ is the weakest part of the masonry wall.
mortar
What is the most important property of mortar?
tensile bond strength of mortar
The ability to bond individual units is measured by the ____ (ASTM C952), which is related to the force required to separate the units.
tensile bond strength of mortar
The _____ affects the shear and flexural strength of masonry.
tensile bond strength
ASTM C91 defines ____ as a measure of the rate at which water is lost to the masonry units.
water retention
____ is a high-slump concrete consisting of portland cement, sand, fine gravel, water, and sometimes lime.
grout
____ is used to fill the cores or voids in hollow masonry units.
grout
Why do we fill the cores or voids in hollow masonry units using grout?
- bonding the masonry units
- bonding the reinforcing steel to the masonry
- increasing the bearing area
- increasing fire resistance
- improving the overturning resistance by increasing the weight
The minimum compressive strength of grout is _____ at 28 days, according to ASTM C476.
14 MPa (2000 psi)
____ is fluid mixture of portland cement, lime sand and water, which is used for finishing either masonry walled or framed (wood) walls.
plaster
____ is used for either exterior or interior walls.
plaster
___ is plaster used to cover exterior walls.
stucco
The average compressive strength of plaster is about ____ at 28 days.
13.8 MPa (2000 psi)
_____ developed a summary table of the sustainable design with concrete masonry units.
Subasic (2013)
_____ is one of the oldest building technologies, dating back to use of sun-dried adobe blocks in ancient times.
masonry
_____ are produced to high standards in the manufacturing process.
modern masonry units
While the strength of the masonry units is important for quality control, the strength of masonry construction is generally _____.
limited by the ability to bond the units together with mortar
The ability of masonry units to resist environmental degradation is an ____ quality of consideration.
important
This ability is closely related to the absorption of the masonry units.
ability of masonry units to resist environmental degradation
