Concrete Math
What are the three givens we have to have in order to complete the formula for the concrete mix design?
Mix Design
Dimensions of the slab
Size of course aggregate
What is used for measuring and loading sand and gravel?
1 CF measuring box
What is used to separate adjacent structural members allowing for differential movment (both vertical and horizontal). It extends completely through the concrete leaving an opening, which is filled with various types of expansion material ?
Isolated Joint
What is the purpose of batter boards?
To preserve the corner locations and provide a reference for prescribed elevations.
What is used to smooth the surface of concrete?
Steel trowel
How do you determine the volume of the slab in cu. yds.?
Take the dimensions of the slab to turn the inches into feet. then multiply it together to get the volume. Then divide by 27 to put it into Cu.yds.
What is used to embed aggregate particles just below the surface, to remove high or low spots, and to compact the concrete at the surface?
Floats
What is used to help control cracking caused by shrinkage by inducing cracks at designated points in slab. They are tooled during the finishing phase of concrete or cut in after the concrete is cured. they do not extend through the concrete?
Control joint
When placing WWF, how much should you overlap end laps, and at what spacing should they be tied?
Overlapping at one full mesh with a tie spacing size of 18" on center
What is used for manual consolidation of concrete after placing?
Spade or puddy stick
What are the rules of thumb when calculating the Design for a concrete mix?
Rule 41 ( -1")
Rule 42 (+1")
What are three diffrent types of floats?
Bull Float
Durby Floats
Hand Float
Is a crack a type of concrete joint?
No it is not a type of joint
What are the three methods of squaring the coners of a structure
1. pythagorean theorem
2.The 3:4:5 meathod
3.Diagonol method
What is used to form a controled joint in fresh concrete?
Jointer / Groover
What is the rounding rule for concrete math also known as the Carpenters rule?
For any decimal round to the nearest hundredths place. Do this for each decimal in the problem.
What is used to force course aggregate slightly below the surface?
Jitterbug
What is used to bond new concrete to existing concrete or as a stopping point in work?
Construction joint
What are three types of rebar support?
High Chair
Continuous high chair
Slab bolster
beam bolster
What is used for mechanical consolidation of concrete; placed at 18" intervals for 5 to 15 seconds?
Mechanical vibrator
Givens:
13'5"x10'x6 1/2"
Aggregate size: 1 15/16 "
mix design 3-6-12
(round to the nearest hundredth)
Cement 17 Cuft
sand 33 Cuft
gravel 65 Cuft
What is capable of mixing 11 CF of concrete (plus 10 persent overloaad)?
11-s concrete mixer
What is used to help control stresses caused by shrinkage and differential movement of the concrete?
Concrete joints
What is the minimum concrete covering for rebar in the following structures?
Footings
Exterior walls
columns
walls
Footings 3"
Exterior walls 2" for larger than #5, 1 1/2" for #5 or less
Columns 1/2"
walls 3/4"
What vary in size and shape according to application, and are designed to hold equipment and structures in place, and positioned prior to the placement of concrete using hanger / templates.
Anchor bolts