ASTM C 143, Slump

Question 1

The slump test provides an indication of the water content of a concrete mixture.
(T or F)

Answer 1

False. It is to determine the consistency of the concrete.

Question 2

A slump mold can be fabricated from materials other than metal.
(T or F)

Answer 2

True. A plastic frustum can be used

Question 3

The length of the tamping rod shall be
A. no more than 4 inches greater than the depth of the mold.
B. at least 4 inches greater than the depth of the mold but not more than 24 inches.
C. not less than 20 inches
D. not less than 12 inches

Answer 3

at least 4 inches greater than the depth of the mold but not more than 24 inches.

Question 4

When rodding the second and third layers of concrete in the measure, the rod should The slump test is applicable to concrete having a nominal maximum size (NMS) coarse aggregate up to _____inch(es) in size.
A. 2
B. 1.5
C. 1
D. 0.75

Answer 4

1.5

Question 5

If the condition of a non‐metal mold is suspected of being out of tolerance, the result of a single comparative test with a metal mod shall not differ more than _____ inch, otherwise the non‐metal mold must be taken out of service.
A. 1.0
B. 0.75
C. 0.50
D. 0.25

Answer 5

0.50

Question 6

The slump mold is filled with concrete in three layers
A. by height.
B. by mass (weight).
C. each consisting of 3 scoops of concrete.
D. by volume.

Answer 6

by volume

Question 7

After a layer of concrete is rodded, the exterior of the slump cone is tapped 10 to 15 with a mallet.
(T or F)

Answer 7

False

Question 8

If, while rodding the third layer of concrete, the top surface of the concrete falls below the top rim of the mold,
A. complete all rodding, then add concrete to fill the mold.
B. stop, add concrete to maintain an excess, then start a new rod count.
C. stop, add concrete to maintain an excess, then continue the rod count from where you left off.
D. stop the test and perform new test on a new sample of material.

Answer 8

stop, add concrete to maintain an excess, then continue the rod count from where you left off.

Question 9

Raise the slump mod vertically, a distance of 12 inches
A. in 5 +/‐ 2 seconds.
B. as quickly as possible.
C. such that the concrete is not able to shear off from one side of the mold.
D. as slowly as possible.

Answer 9

n 5 +/‐ 2 seconds

Question 10

The slump of a mixture is found by measuring
A. the vertical distance to the lowest point on the surface of the concrete.
B. the vertical distance to the highest point on the surface of the concrete.
C. to the high and low points on the surface, then taking and average.
D. the vertical distance to the displaced original center on the surface of the concrete.

Answer 10

the vertical distance to the displaced original center on the surface of the concrete.

Question 11

Complete the slump test without interruption, from the start of filling the mold through the removal of the
mold, within an elapsed time of _____ minute(s).
A. 1
B. 2.5
C. 5
D. 15

Answer 11

2.5

Question 12

Report the measured slump to the nearest _____ inch.
A. 0.10
B. 1/4
C. 1/2
D. 1

Answer 12

1/4

Question 13

The slump test is not applicable to non‐plastic and non‐cohesive concrete.
(T or F)

Answer 13

True

Question 14

Concrete is placed in the slump mold with a _____.
A. scoop or shovel
B. shovel
C. scoop
D. scoop, shovel or by hand

Answer 14

Scoop

Question 15

Rod each layer of concrete _____ times
A. 10
B. 15
C. 20
D. 25

Answer 15

25

Question 16

_____ consolidate the concrete in the slump mod by vibration.
A. When the slump is less than 1 inch
B. When the slump is less than 3 inches, it is permissible to
C. When the slump is between 1 and 3 inches, it is permissible to
D. It is never permissible to

Answer 16

it is never permissible to

Question 17

After striking off any excess concrete,
A. immediately raise the slump mold a distance of 12 inches.
B. remove the concrete from the area surrounding the base of the mold.
C. identify the original center of the top surface of the concrete.
D. transfer your weight from the foot fins to the hand holds.

Answer 17

remove the concrete from the area surrounding the base of the mold.

Question 18

If after raising the mold there is a shearing off or falling away of material from the mass of concrete,
A. disregard the test and perform a new test on another portion of the sample.
B. the concrete is considered to be non‐plastic or non‐cohesive.
C. re‐run the slump test using the same portion of the sample.
D. measure the slump of the larger mass of slumped concrete.

Answer 18

disregard the test and perform a new test on another portion of the sample.

Question 19

Measuring device for slump can be:

Answer 19

Ruler or measuring tape of at least 12” and marked every 1/4 in or less.

Question 20

Procedure of slump test

Answer 20

1. Dampen inside of cone and plate
2. Fill a third by volume
3. Rod 25 times
4. Repeat
5. Repeat
6. Use rod to remove excess concrete
7. Clean around base of cone
8. Lift cone between 3-7 seconds
9. Flip cone over and place rod on top
10. Use measuring tape to measure the center of the cone
11. Measure to the nearest 1/4 in
12. Complete writhing 2 mins 30 seconds

Question 21

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

Answer 21

Frustum of a cone

Question 22

The height of a slump cone is?

Answer 22

12”

Question 23

The end of a tamping rod must be what in shape?

Answer 23

Hemispherical

Question 24

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

Answer 24

Flat, level, damp, nonabsorbent, and rigid