Concrete Basics
What are the BASIC materials needed for concrete?
Cement, water, aggregates, air
What does SCM stand for?
Supplementary Cementitious Material
How many types of blended cements did we learn about (and what are they)?
4 total - IP, IL, IS, IT
How many stages of Cement Hydration are there?
5 total stages!
What is the allotted amount of time to perform the Slump Test (ASTM C143)?
2 1/2 Minutes (150 seconds)
What is the largest consumption of concrete in the US?
Ready-Mix Concrete
What is Fly Ash a biproduct of?
Burning coal in power plants
What does the subcategory LH mean?
Low Heat of Hydration
What is the name for C4AF?
Tetracalcium Aluminoferrite
What should you ALWAYS do after you perform any ACI test?
Clean equipment thoroughly to ensure no concrete residue is left behind!!!
Fill in the blank:
_______ Cement Concrete
Portland (From the island, not the city!)
Ground Granulated Blast Furnace Slag
What are some benefits of Rapid Hardening Cements, how many types are there and what would the applications of it be?
1. High early strength and low setting time
2. Four Types - URH, VRH, MRH, GRH
3. Fast-track paving and road construction
What is the principal hydration product?
How many times do you have to rod per layer of concrete when performing ASTM C231 (Pressure Air Test)?
25 rods per layer
Why do we want a lower w/cm rather than a higher one?
Less shrinkage, more strength and durability!
What is the maximum replacement of cement allowed with SCMs?
50 percent!
How many grades of Oil-Well Cements are there?
3 Total - Ordinary, moderate sulfate resistance, high sulfate resistance
What can cause flash set? (HINT: think of which product is involved)
C3A hydrates too rapidly
What is the temperature range for initial curing of beams and cylinders? (less than 6000 psi)
60o F to 80o F
What percentage of concrete is aggregateon average?
Roughly 60% to 80%
What are the 3 forms that Silica Fume can be supplied?
As produced (fine powder), Slurry, Densified
How would you write this out?
"A Tertiary blended cement of 12% Slag and 15% Pozzolan with ASR resistance and low heat of hydration."
Type IT (P15)(S12)(R)(LH)
Explain "False Set" and "Flash Set", and how to fix both of these problems.
You just performed your Rollmeter Air Test (ASTM C173) and you noticed that the air dropped 0.25 percent in between your initial reading and second reading. What do you do?
Record the second reading as the final reading! (Good job you just completed the worst ACI test lol!)