Masonry Flashcards
what does CMU stand for
Concrete Masonry Unit
what is the weight of a CMU
35-45 lbs
what are the nominal and actual dimensions of a CMU
nominal dimensions: 8” x 8” x 16”
actual dimensions: 7 5/8 “ x 7 5/8 “ x 15 5/8 “”
what is the weight of cinder blocks
25-35 lbs
what are some desirable properties of mortar
- plasticity
- water retentivity
- strength and durability
which cement already contains masonry lime
masonry cement contains masonry lime
portland cement you have to add it
what are the types of mortar
- type m
- type s
- type n
- type o
when hand mixing mortar what material do you place first
place the sand first then mix all dry materials before adding water
what is the mixing time for mortar when using a machine
3-5 min
first place most of the water then half of the sand, then cement and rest of the sand
what are the two types of sand
manufactured and natural
true or false
calcium chloride should not be used for steel re-inforced masonry
true
what is calcium chloride
can be used as an accelerator
what two mortar materials should not be stored in a dry place
lime and sand
they should be covered to prevent moisture loss
what are the parts of a masonry wall
- corners/end
- field
- control/expansion joints
- wall intersections
- rough openings
when laying the corners how many courses high should they be
4 to 5 courses high
step each course back one half block
when “checking the rack” what angle should the block courses be
45 degrees
when laying the closure block, how much gap should be left
16 1/2 “ gap
when placing anchor bolts, how far apart should they be
12” from the corners, the no more than 4’ apart after that
what is the rule of thumb when placing control/expansion joints in masonry walls
no more than 25’ between joints, not more than 1/2” mortar
what is modular coordination
when the design of a building, it’s components, and the building material units all conformto a dimensional standard based on our modular system
what is modular measure
the system of dimensional standards for buildings and building components that permit field assembly without cutting
what does planning save
- considerable labor
- time
- materials
what are lintels
lintels are used to support masonry block over modular openings such as doors and windows in walls
what are sills
sills are used to create a finished look for the bottom of openings in walls. they are usaually precast and installed following wall construction
when do you tool/strike mortar joints
when they become “fingerprint” hard
which joints do you strike first
vertical then horizontal
