問題一覧
1
Why is the sub-grade and forms dampened prior to placement of the concrete:
prevent extraction of hydration water
2
Concrete slabs should be placed with what slump:
2-4
3
What is the maximum length of a safety lanyard:
6’
4
What of the following is acceptable for rebar:
rust
5
OSHA requires what minimum overlap for planking on a scaffold:
12”
6
What tie would be used to hold rebar in place for a vertical wall pour:
tie wire
7
What is the minimum depth of a footer placed in undisturbed soil not exposed to bad weather:
12”
8
OSHA requires cave-in protection for trenches at what minimum depth:
5 feet
9
Form lateral pressures increase by what percentage if a concrete blend has 70% slag or 40% fly ash:
40%
10
What is the best way to compact sandy soils:
controlling the water content and with water
11
If the ground slopes 10 feet between a marker at 75 feet to another marker at 125 feet, what is the total slope:
20%
12
What admix is used with concrete being placed in very hot weather:
retarder
13
What is the minimum cover for rebar from the surface of a mat:
1”
14
From the initial mixing of concrete to the actual pour, ASTM 94 requires what maximum amount of time:
1 1/2 hours
15
If you have an excavation with a rod reading of 94 and the backsite to the trench is (100') with an elevation of 4.7 what does the stake read:
10.7
16
Footings shall be how many inches wider than the wall it supports for residential construction:
8"
17
A simple way to kno when to continue concrete finishing after waiting for the bleed water to evaporate is to step on the concrete leaving an indentation of less than:
1/4"
18
What is the best form for a heavy concrete column:
locking column clamp
19
What is the minimum depth of a footer placed in undisturbed soil not exposed to bad weather:
12”
20
What admix is added to the concrete batch to create high early concrete:
accelerator
21
If you intend to resuse plywood form material which of the following would be used:
exterior grade
22
Typically a joist chair holds how many rebar:
2
23
What concrete finish is provided for exposed architectural concrete:
class 1 (I)
24
What must be provided someone operating a grinder that is classified as hazardous work:
full face shield
25
What should be applied to form wood to ease removal:
release agent
26
What is the maximum height from which concrete should be dropped from the chute:
5’
27
How many days should new concrete vure before adding waterproofing materials to the concrete:
7
28
Dirt from excavations must be set back how far from edge of the trench:
2’
29
Air entertainment improves freeze and thaw resistance and what else:
workability
30
In a working trench with very unstable ground, what device provides the greatest worker safety:
trench box