問題一覧
1
What concrete would be used in areas with high phosphate content:
Type V
2
What concrete has the greatest compressive strength:
M
3
What causes rebar to bond to concrete better:
rust
4
What is the maximum safe load for a form system using snap ties:
3350 lb
5
The ability of concrete to resist abrasion is closely linked to what other concrete trait:
porosity
6
Dirt from excavations must be set back how far from the edge of the trench:
2’
7
How much dirt is removed from a trench 120 feet long, 2 1/2 feet wide and 5 feet deep, excluding the swell factor for the soil:
55.56 cubicyards
8
Scaffold planks must overextend their upright supports by how many inches:
12”
9
Rebar adds what strength to concrete structures:
tension
10
What is the minimum number of mixing revolutions for concrete under ASTM 94:
75-100
11
Adding additional Water to an already workable mix of concrete causes what:
decrease in strength
12
What is the minimum thickness for a lightweight concrete deck:
2”
13
If the rod reading is 165 and the finished rod reading is supposed to be 163 and the transit height is 5.7 feet, what will the reference stake read:
fill 2.00
14
What is added to mix to slow curing during hot weather:
retarders
15
For an excavation, what is used as the beginning reference point:
benchmark
16
Plastic shrinkage cracks that occur in concrete during hot weather placement is usually due to what:
rapid loss of surface water
17
What is the minimum spacing for a placed rebar in a reinforced wall:
3 times the width of the wall or 18"
18
If digging a trench 5 feet wide, 60 feet long in ground that has a constant slope from O to 8 feet, how many cubic yards of soil will be removed:
between 40 and 45
19
Rank types of concrete by strength going from highest to lowest:
M.S.N.O
20
If working in a trench 5' or more in depth, what is the best way to prevent trench side wall collapse accidents on employees working in the trench:
shoring box
21
What is the most common Portand cement added to concrete:
Type l
22
Placing concrete in cold weather causes what:
slow curing
23
What is the maximum recommended slump for concrete used in footings:
6
24
How much water is allowed to accumulate in a working open trench:
0”
25
If digging a trench that has c continuous slope from O' to 8' that will be 5' wide and 60' long, not considering swell, how many cubic yards of dirt will be excavated:
43-46
26
What type of Portland cement produces high early compressive strength:
Type IlI
27
What type of exterior grade plywood is best used for large concrete forms:
HDO
28
Form lateral pressures increase by what percentage if adding retarder to Type I, Il, or Ill concrete mixes:
20%
29
What type of Portland concrete produces high early compressive strength:
type III
30
Air entertainment improves freeze and thaw resistance and what else:
workability
31
What is the diagonal for an excavation measuring 28 × 45:
53’