Masonry Exam 1 Questions and Answers 2023 with
complete solution
The basic components of Masonry?
Mortor, Grout, Masonry Units, Accessary Materials
Two dimension sizes of masonry units?
16" long X 8" wide or 12" wide X 8" Tall
Are solid unites 100% solid unless so specified?
No
What percent solid do hollow masonry units vary from?
40%-75% solid
What is the specification code for masonry?
TMS 602
What is covered in the masonry specification?
Concrete masonry units
Clay or shale material
Autoclaved aerated concrete masonry units
Stone units
Glass units
What is the main ASTM that engineers deal with most?
ASTM C90
What does ASTM C90 reference?
Specification for Loadbearing Concrete Masonry Units
Concrete units normally have a higher or lower void ratio than clay units?
Higher
What ASTM are Visual and Serviceability Characteristics of Concrete Masonry
Units addressed in?
ASTM C90
What is the maximum face shell and web thickness?
plus or minus 1/8"
What does it mean when we want units to coarse?
We want the height of the wall to be divisible by 8" with no remainder
What is the minimum compressive strength of concrete masonry units?
2000 psi
What is Mortor?
Bonding agent that holds the individual units.
What is mortor composed of?
Cementitious agents
Sand
Water
What ASTM is masonry mortor addressed in?
ASTM C270
Mortars with high cement content have what?
Higher compressive strength
Mortars with high lime contents have what?
, Better workability
Higher water retention
What happens to unhydrated lime in mortar over time?
It hydrates over time causing expansion and potential cracking in the mortar
Who choses the mortar type related to the proportion of cement in mortar?
Designer
What are the three types of mortar?
Cement-Lime Mortar
Masonry-Cement Mortar
Mortar-Cement Mortar
What are the advantages of Cement-Lime Mortar?
High tensile bond strength
High water contents=satisfy water demands
Hydrated lime and water enhance bond
Hardens slowly=fills hairline cracks
Disadvantages of Cement-Lime Mortar?
Complex Mixing
Lack of workability if not retempered
Can freeze in cold weather
Higher lime content needed in dry, hot weather conditions
What is masonry-cement mortar composed of?
mixtures of portland or blended cement and plasticizing materials.
What are the advantages of masonry-cement mortar?
Simple batching
Good workability
Good productivity
Requires less water=good for cold weather
What are the disadvantages of masonry-cement mortar?
Low bond strength
Low water content is not good for hot weather
Prohibited in seismic zones
Profitable "niche" product to cement producers
When was mortar-cement mortar introduced and why?
1990s
To preserve construction advantages and potential profitability of masonry cement
What is the mortar proportion specification?
It is the default and presumed unless the designer states otherwise
What is the most important characteristic of fresh mortar?
Workability
What is workability of mortar?
Ability for the mortor to be easily spread on CMU with a trowel
What flow should laboratory mixed mortars have?
110 plus or minus 5
Field mortars should have flows in what range?
130-150
What should you do to field mortars to maintain workability?
complete solution
The basic components of Masonry?
Mortor, Grout, Masonry Units, Accessary Materials
Two dimension sizes of masonry units?
16" long X 8" wide or 12" wide X 8" Tall
Are solid unites 100% solid unless so specified?
No
What percent solid do hollow masonry units vary from?
40%-75% solid
What is the specification code for masonry?
TMS 602
What is covered in the masonry specification?
Concrete masonry units
Clay or shale material
Autoclaved aerated concrete masonry units
Stone units
Glass units
What is the main ASTM that engineers deal with most?
ASTM C90
What does ASTM C90 reference?
Specification for Loadbearing Concrete Masonry Units
Concrete units normally have a higher or lower void ratio than clay units?
Higher
What ASTM are Visual and Serviceability Characteristics of Concrete Masonry
Units addressed in?
ASTM C90
What is the maximum face shell and web thickness?
plus or minus 1/8"
What does it mean when we want units to coarse?
We want the height of the wall to be divisible by 8" with no remainder
What is the minimum compressive strength of concrete masonry units?
2000 psi
What is Mortor?
Bonding agent that holds the individual units.
What is mortor composed of?
Cementitious agents
Sand
Water
What ASTM is masonry mortor addressed in?
ASTM C270
Mortars with high cement content have what?
Higher compressive strength
Mortars with high lime contents have what?
, Better workability
Higher water retention
What happens to unhydrated lime in mortar over time?
It hydrates over time causing expansion and potential cracking in the mortar
Who choses the mortar type related to the proportion of cement in mortar?
Designer
What are the three types of mortar?
Cement-Lime Mortar
Masonry-Cement Mortar
Mortar-Cement Mortar
What are the advantages of Cement-Lime Mortar?
High tensile bond strength
High water contents=satisfy water demands
Hydrated lime and water enhance bond
Hardens slowly=fills hairline cracks
Disadvantages of Cement-Lime Mortar?
Complex Mixing
Lack of workability if not retempered
Can freeze in cold weather
Higher lime content needed in dry, hot weather conditions
What is masonry-cement mortar composed of?
mixtures of portland or blended cement and plasticizing materials.
What are the advantages of masonry-cement mortar?
Simple batching
Good workability
Good productivity
Requires less water=good for cold weather
What are the disadvantages of masonry-cement mortar?
Low bond strength
Low water content is not good for hot weather
Prohibited in seismic zones
Profitable "niche" product to cement producers
When was mortar-cement mortar introduced and why?
1990s
To preserve construction advantages and potential profitability of masonry cement
What is the mortar proportion specification?
It is the default and presumed unless the designer states otherwise
What is the most important characteristic of fresh mortar?
Workability
What is workability of mortar?
Ability for the mortor to be easily spread on CMU with a trowel
What flow should laboratory mixed mortars have?
110 plus or minus 5
Field mortars should have flows in what range?
130-150
What should you do to field mortars to maintain workability?
