TECHNICIAN LEVEL 1 EXAM 2025 |
GUARANTEED ACCURATE
ANSWERS
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? - ACCURATE
ANSWERS✔✔ 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?
- ACCURATE ANSWERS✔✔ 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 - ACCURATE ANSWERS✔✔ 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 - ACCURATE ANSWERS✔✔ 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? - ACCURATE
ANSWERS✔✔ 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? - ACCURATE
ANSWERS✔✔ 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.
c Slow the rate of temp rise in mass concrete and lower the peak temp
thereby reducing thermal cracking.
d. Delay initial set for special finishes such as exposed aggregate. -
ACCURATE ANSWERS✔✔ A: Reduction of 28 day strength. Early
strength reduction is expected, but strength at later stages is not affected
when using retarders
Pozzolans are beneficial in concrete because:
a. They provide for water disposal
b. They make the mixture less sticky for finishing
c. They react with calcium hydroxide to provide cementitious benefits