ACI Curing, Protection & Quality Control 2

Question 1

What is the minimum curing period recommended by ACI 308 for concrete made with Type I/II cement under normal temperature conditions?

Accepted Answer

7 days

Answer

ACI 308 recommends a minimum of 7 days of curing for concrete made with Type I/II cement at normal temperatures.

Question 2

Which curing compound application method ensures the most uniform coverage on a freshly finished slab?

Accepted Answer

Spray application in two passes at right angles

Answer

Spraying curing compound in two perpendicular passes ensures overlapping, uniform coverage with no missed areas.

Question 3

Hot weather concrete placement is generally considered to occur when ambient temperature exceeds what threshold?

Accepted Answer

90°F (32°C)

Answer

ACI 305 defines hot weather concreting conditions as those where ambient temperature exceeds 90°F (32°C).

Question 4

A slump test result that is 2 inches higher than specified most likely indicates which quality control problem?

Accepted Answer

Excess water added at the jobsite

Answer

Excess slump beyond specification is the classic indicator of unauthorized water addition, which increases w/c ratio and reduces strength.

Question 5

Which type of curing blanket is most appropriate for protecting concrete from freezing temperatures?

Accepted Answer

Insulating blankets with foam core

Answer

Insulating blankets with foam cores provide both moisture retention and thermal protection needed to prevent freezing.

(ACI) American Concrete Institute Concrete Finisher Practice Test