Guide Questions With Complete Solutions
You will need early strength from a concrete mixture design in order to strip the
product as soon as possible. What type of cement should you consider and what
characteristics make it a good choice?
ASTM C150 Type III cement is used when early strength is desired. It is ground finer
than the other cements and will react with water faster.
Fine and coarse aggregates should generally conform to which standard?
Unless specifically stated otherwise, they should both conform to ASTM C33
How are fine and coarse aggregates defined by the standard and how does a
plant check these criteria
Fine and coarse aggregates are generally defined by ASTM C33 in relationship to their
gradation or particle size, distribution and fineness for sand. I plant reviews material by
testing for and computing the gradation.
Non-drinkable water should not be used to make concrete - ture or False? Explain
False - Water suitable for making concrete does not need to be fit for drinking, but non-
potable water must meet the chemical limits given in table C3.1.6 of PCI manuals MNL-
116 and 117
As a general statement, what are admixtures?
In a general sense, any item added to concrete other than cement, aggregates, and
water is an admixture
Chorides are detrimental to precast concrete because?
B: Chlorides promote corrosion of embedments, reinforcing, and prestressing strand.
Which of the following is not a benefit of using retarders as admixtures?
a. Reduction of 28 day strength
b. Offset the adverse effects of hot weather (ambient temp that exceeds 85 F) by
delaying the setting of concrete and maintaining the workability for a longer
period of time.