Test Method C143: Slump of Hydraulic-Cement Concrete

Question 1

The slump test is applicable to plastic concrete with a max size aggregate of ___.

Answer 1

1.5 inches

Question 2

When the concrete contains aggregate larger than allowed for the slump test, the large aggregate must be ____.

Answer 2

Removed by wet sieving the sample over 1.5 inch sieve

Question 3

The mold for making the slump test is in the shape of ____.

Answer 3

The frustum of a cone

Question 4

The height of the slump mold is___.

Answer 4

12 inches

Question 5

The interior surface of the slump mold is allowed to have minor irregularities. T/F

Answer 5

False

Question 6

For use in the slump test, the end or both ends of the tamping rod must be ____.

Answer 6

Rounded to a hemispherical tip

Question 7

The sample of concrete for use in making the slump test must be obtained in accordance with ASTM Standard.

Answer 7

C172, Standard Practice for Sampling Freshly Mixed Concrete

Question 8

The slump mold should be in a dry condition before beginning the test. T/F

Answer 8

False

Question 9

The surface on which the slump mold will be placed must be ___.

Answer 9

Flat, level, moist, nonabsorbent, and free of vibration.

Question 10

The slump mold is filled in ___ layers.

Answer 10

3

Question 11

Each layer should fill approx ___ the volume of the mold.

Answer 11

1/3

Question 12

The approx concrete depth (in vertical distance) after placing the first layer is ____, and the second layer is ____.

Answer 12

2 5/8 in. 6 1/8 in.

Question 13

What is the specified number of roddings for each layer?

Answer 13

25

Question 14

How deep should the tamping rod penetrate into each layer?

Answer 14

Rod each layer through its depth and into the previous layer approx 1 inch.

Question 15

When rodding the bottom layer, the tamping rod must be ___ to uniformly distribute the strokes.

Answer 15

Slightly inclined

Question 16

What must be done if the concrete drops below the top of the slump mold while the top layer is being rodded?

Answer 16

Add additional concrete to keep an excess of concrete above the top of the mold at all times.

Question 17

Prior to lifting the mold, concrete must be removed from ___.

Answer 17

The area surrounding the base of the mold.

Question 18

After the final rodding, the sides of the slump mold should be tapped lightly with the tamping rod. T/F

Answer 18

False

Question 19

When raising the slump mold, it should not be rotated or twisted. T/F

Answer 19

True

Question 20

How much time is allowed for lifting the slump mold?

Answer 20

5 +/- 2 seconds

Question 21

The measurement for slump is made from the top of the mold to what point of the concrete specimen?

Answer 21

The displaced original center of the top surface of the specimen.

Question 22

The slump of the concrete is measured and reported to the nearest _____.

Answer 22

1/4 inch

Question 23

How much time is allowed to conduct the slump test from beginning to completion?

Answer 23

2.5 minutes