ASTM C143/C143M - Standard Test Method for Slump of Hydraulic Concrete

Question 1

Maximum aggregate size for slump testing is ___?

Answer 1

1.5 inches

Question 2

Dimensions of the slump cone are?

Answer 2

4” diameter @ top
8” diameter @ bottom
12” high

Question 3

Slump cone can be made of which materials?

Answer 3

Metal or Plastic

Question 4

Metal slump cone thickness is ____ ?

Plastic slump cone thickness is ____?

Answer 4

.06 inches (1.5 mm) for metal

.125 inches (3 mm) for plastic

Question 5

Sample of concrete for use in performing the slump test must be obtained in accordance with which ASTM practice?

Answer 5

ASTM C172

Question 6

Slump cone is filled in ___ layers of equal ______?

Answer 6

3 layers of equal VOLUME

Question 7

How deep should the bottom layer of concrete be?

How deep should the second layer of concrete be?

Answer 7

bottom layer = 2 5/8 inches

second layer = 6 1/8 inches

Question 8

Interior of slump cone must be ________ prior to inserting concrete into the mold.

Answer 8

Dampened

Question 9

If concrete drops below the top of the slump mold when rodding the final layer, what should you do?

Answer 9

Stop rodding, fill the cone with more of the sample and then continue rodding where you left off

Question 10

Strike off the top of the cone with which device?

a - Tamping Rod
b - Strike-off bar
c - Strike-off plate

Answer 10

a - Tamping rod

Question 11

Strike off the top of the cone using a ______ motion?

a - Sawing
b - Twisting
c - Both

Answer 11

c - Both

Question 12

If a decided falling away, or shearing off of concrete from one side or portion of mass occurs, disregard the test and ____________________?

Answer 12

Make a new test from the same sample portion.

Question 13

If two consecutive tests on a sample of concrete show a falling away or shearing off of a portion of the concrete from the mass of the specimen, the concrete probably lacks necessary _______ and ________ for the slump test to be applicable.

Answer 13

Plasticity

Cohesiveness

Question 14

TRUE or FALSE:

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

Answer 14

True

Question 15

TRUE or FALSE:

Sides of the cone need to be tapped with open hand after consolidation of each later

Answer 15

False - Slump cone does not require tapping/striking

Question 16

To determine slump, measure vertical distance between top of cone and ______________?

Answer 16

Displaced original center of top surface

Question 17

What are the two ways of holding down the slump cone?

Answer 17

Feet

Clamps

Question 18

Slump cone should be raised carefully, vertically upward, in a steady motion and take no more than _______ seconds

Answer 18

5 [+/- 2] seconds

Question 19

Elapsed time between start of filling cone and the removal of the cone should not exceed ____ minutes?

Answer 19

2 1/2 minutes

Question 20

Slump is measured to the nearest ____

Answer 20

1/4 inch

Question 21

Rod each layer of concrete ____ times

Answer 21

25

Question 22

Interior of slump cone should be (1)______, have no (2)______, and be free from (3)_____ or (4)_____.

Choose from the list below:
a - Moisture
b - Dents
c - Smooth
d - New
e - Projections
f - Aggregates
g - Seems
h - Plastic

Answer 22

(1) = a - Smooth
(2) = b - Seems
(3) = c - Projections
(4) = b - Dents

Question 23

TRUE or FALSE:
Place the slump mold on a surface that is rigid, flat, level, moist, nonabsorbent, free of vibration and that is a minimum of 2” bigger than the base of the mold

Answer 23

False - the surface needs to be rigid, flat, level, moist, nonabsorbent, free of vibration and that is LARGE ENOUGH TO CONTAIN ALL OF THE SLUMPED CONCRETE.

Question 24

Slump form to be in the shape of ____________

Answer 24

Frustum of a cone

Question 25

To measure the slump, the measuring device must be at least _____ inches long with increments of at least ____ inch.

Answer 25

12 inches long

Increments of at least 1/4 inch

Question 26

When filling the cone with a scoop, should you:

A - dump the concrete directly into the top hole of the mold at an initial depth of 2 5/8”

or

B - Move the scoop around the perimeter of the mold opening to ensure an even distribution of the concrete to an initial depth of 2 5/8”

Answer 26

B - Move the scoop around the perimeter of the mold opening to ensure an even distribution of the concrete to an initial depth of 2 5/8”