READY-MIX

Concrete Facts

The vibration of fresh concrete is only as good as the man running the vibrator, for instance…

Over-vibration can cause honeycomb instead or eliminating it as intended
Inadequate vibration is sure to result in honeycomb, particularly with low slump concrete.
High slump concrete can not stand as much vibration as low slump: very wet concrete, non at all.
Over-vibration will cause loss of entrained air-as much as 50% loss in 30 seconds.
Moving concrete around in the form by using the vibrator will result in sand streaks and rock pockets.
Cold joints may result even though each lift is vibrated unless the vibrator penetrates just into the lower lift.
Partially set concrete can be revibrated without harm provided the vibrator would enter the concrete of its own weight and restore the concrete to a plastic state.
A vibrator setting at a flat angle has little effect, if any, on the concrete immediately below.

JOINTS IN CONCRETE
FACT: CONCRETE
SHRINKS
AS IT DRIES,THUS
IT WILL CRACK

Joints are simple good looking Pre-Planned Cracks
There are two basic joints to remember;
- Contraction Joints… Tooled or saw cut into slab to direct crack
- Expansion Joints… These isolate the slab from other structures
Joints should be carefully designed and properly constructed.
For further information, contact us

ONE CUBIC YARD OF
CONCRETE WILL COVER

THICKNESS IN INCHES

10"

SQUARE FEET

320

160

107

PROPER CURING
OF COLOR

One of the most important steps in the process of placing color conditioned concrete is the curing process. Curing is defined as the maintaining of a satisfactory moisture content and temperature in concrete for a definite period of time (preferably 7 days), in order to develop the desired properties (strength, durability, water tightness) in concrete. It will also allow the color to develop to its full potential and be uniform in appearance. If there is no curing done, or if it is done incorrectly, you can be guaranteed that discoloration will arise as well as potential for efflorescence and you will have a call back to the job.

RECOMMENDED JOINT SPACING

SLAB

THICKNESS

3 Inches

3.5 Inches

4 Inches

5 Inches

LESS THAN 3/4"

AGGREGATE

6 Foot

7 Foot

8 Foot

10 Foot

LARGER THAN 3/4"

AGGREGATE

8 Foot

9 Foot

10 Foot

13 Foot

Note: Depth of the control joints in the slab should be 1/4 to 1/3 thickness of the slab.

IF YOU ADD ONLY ONE GALLON OF WATER TO A YARD PROPERLY DESIGNED 3000 PSI CONCRETE:

You increase the slump about one inch
You cut the compressive strength by as much as 250 psi
You waste the effect of 1/4 bag of cement
Your increase the possibility of seepage through the concrete by up to 50%
You increase the shrinkage potential about 10-15%
You decrease the Freeze-thaw resistance by 20%
You lower the quality of concrete in many other ways
- Less wear resistance
- Dusting
- Cracking
- Repairs
You can affect setting times in cold weather (Retard)

CONCRETE SETTING TIMES

The setting of concrete is a physical-chemical reaction. Generally, this chemical reaction is altered by approximately 1/3 for each 10 degree F change.

As an example of the relationship between temperature and setting times, concrete, at 70 degrees F sets in about 6 hours. Assuming that both the concrete and ambient temperatures are the same, here’s when you can expect concrete to reach initial set at other temperatures.

TEMPERATURE

100 °F

90 °F

80 °F

70 °F

60 °F

50 °F

40 °F

30 °F

APPROX. SETTING TIME

1 – 2/3 hours

2 – 2/3 hours

4 hours

6 hours

8 hours

10 – 2/3 hours

14 – 2/3 hours

19 plus hours