C143/C143M - 15a: Slump of Hydraulic-Cement Concrete Flashcards
The slump test is applicable to plastic concrete with a maximum size aggregate of
1.5”
When the concrete contains aggregate larger than allowed for the slump test, the large aggregate must be
Wet sieved
The mold for making the slump test is in the shape of
A cone
The height of the slump mold is
12” I 1/8”
True or False?:
The interior surface of the slump mold is allowed to have minor irregularities
False
For use in the slump test, the tamping end of both ends of the tamping rod must be
Rounded to a hemispherical tip of same diameter as rod
The sample of concrete for use in making the slump test must be obtained in accordance with practice
C172
True or False?
The slump mold should be in a dry condition before beginning the test.
False
The surface on which the slump mold will be placed must be
Flat, moist, non absorbent and rigid
The slump mold is filled in
3 layers
Each layer should fill approximately
1/3 the volume of the mold.
The approximate concrete depth (in vertical distance) after placing the first layer is ________ and the second layer is _________
2 5/8”
6 1/8”
Rod each layer ______times uniformly over the cross section with the rounded end of the rod.
25
How deep should the tamping rod penetrate into each layer?
The entire length of layers plus 1” for upper two layers
When rodding the bottom layer, the tamping rod must be ___________ to uniformly distribute the strokes.
Inclined Slightly
What must be done if the concrete drops below the top of the slump mold while the top layer is being rodded?
Add more concrete and continue rodding count from last blow
Prior to lifting the mold, concrete must be removed from ________________
The top of the core and around the base mold
True or False?:
After the final rodding, the sides of the slump mold should be tapped lightly with the tampering rod.
True
True or False?:
When raising the slump mold, it should not be rotated or twisted.
True
How much time allowed for lifting the slump mold?
+ 2 seconds
The measurement for slump is made fr the top of the mold to what point of the concrete specimen?
Displaced original center of the top surface at specimen
The slump of the concrete is measured and reported to the nearest _________
1/4”
How much time is allowed to conduct the slump test from beginning to completion?
2 1/2 minutes
