288 322
288
MASONS SUPPLY COMPANY
Oregon (800) 537-3407 ♦ Washington (800) 537-6216
Clackamas | Eugene | West Eugene | Hillsboro | Medford | Portland | Salem | Wilsonville | Ridgefield | Seattle | Tacoma | Woodinville
M A S C O . N E T
GENERAL & TECH INFO
Concrete Volume
One cubic yard of concrete (27 ft
3
)
will cover:
Concrete Jointing
"Concrete cracks. The trick is to get it
to crack where you want it to."
Joint Types:
Contraction Joints
– Tooled in or saw cut into slab.
Construction Joints
– Area where two successive
placements of concrete meet.
Isolation Joints
– Used to effectively isolate a section or
area of the slab from other areas of the slab.
Joints are designed and implemented into the project as much
as the concrete mix is. Properly designed and implemented joints
can add years to the service life of the slab.
Concrete Setting / Stiffening
The chemical process by which concrete hardens
and gains strength is called hydration. Hydration
time can be altered by as much as 30% for each
10°F change in ambient temperature.
Typical concrete placed at 70°F (concrete
temperature and ambient temperature) achieves
final set in about 6 hours. Concrete and ambient
temperatures will affect the setting of the concrete
as shown in the table to the right:
Concrete
Thickness
(in)
Coverage
Area
(ft
2
)
4
81
5
64.8
6
54
7
46
8
40.5
9
36
10
32.4
11
29.5
12
27
CONCRETE TIPS
Adding Water
"Water is the best / worst thing you can add to your
concrete."
Adding one gallon of water to one cubic yard of a typical
3000 psi concrete can:
• Increase the slump by about one inch
• Reduce the compressive strength by about 250 psi
• Increase the possibility of passage of moisture
throughout the concrete by up to 50%
• Increase the shrinkage potential by about 10%
Properties also affected water addition:
Lessened
wear resistance
Increased
dusting potential
Increased
cracking potential
Reduced
durability
Temperature
(
°
F)
Approximate Final Set (hours)
30
19 +
40
14:40
50
10:20
60
8
70
6
80
4
90
2:40
100
1:40