EXAM QUESTIONS AND SOLUTIONS 100
PERCENT CORRECT
◉ The interior surface of the slump mold is allowed to have minor
irregularities. True or False? Answer: False
◉ For use in the slump test, the end or both ends of the tamping rod
must be _____. Answer: Rounded to a hemispherical tip
◉ The sample of concrete for use in making the slump test must be
obtained in accordance with ASTM Standard _____. Answer: C172,
Standard Practice for Sampling Freshly Mixed Concrete
◉ The slump mold should be in a dry condition before beginning the
test. True or False? Answer: False
◉ The surface on which the slump mold will be placed must be _____.
Answer: Flat, level, moist, nonabsorbent, and free of vibration
◉ The slump mold is filled in _____ layers. Answer: 3
,◉ Each layer should fill approximately _____ the volume of the mold.
Answer: One-third
◉ The approximate concrete depth (in vertical distance) after
placing the first layer is _____, and the second layer is _____. Answer:
2⅝ in. [70 mm], 6⅛ in. [160 mm]
◉ What is the specified number of roddings for each layer? Answer:
25
◉ How deep should the tamping rod penetrate into each layer?
Answer: Rod each layer throughout its depth; on the second and
final layers, the rod should penetrate into the previous layer
approximately 1 in. [25 mm]
◉ When rodding the bottom layer, the tamping rod must be _____ to
uniformly distribute the strokes. Answer: Slightly inclined
◉ What must be done if the concrete drops below the top of the
slump mold while the top layer is being rodded? Answer: Add
additional concrete to keep an excess of concrete above the top of
the mold at all times
◉ Prior to lifting the mold, concrete must be removed from _______.
Answer: The area surrounding the base of the mold
, ◉ After the final rodding, the sides of the slump mold should be
tapped lightly with the tamping rod. True or False? Answer: False
◉ When raising the slump mold, it should not be rotated or twisted.
True or False? Answer: True
◉ How much time is allowed for lifting the slump mold? Answer: 5 ±
2 seconds
◉ The measurement for slump is made from the top of the mold to
what point of the concrete specimen? Answer: The displaced
original center of the top surface of the specimen
◉ The slump of the concrete is measured and reported to the
nearest _____. Answer: ¼ in. [5 mm]
◉ How much time is allowed to conduct the slump test from
beginning to completion? Answer: 2½ minutes
◉ ASTM C138 Answer: Standard Test Method for Density (Unit
Weight),
Yield, and Air Content (Gravimetric) of Concrete