Test Method C143: Slump of Hydraulic-Cement Concrete Flashcards
The slump test is applicable to plastic concrete with a max size aggregate of ___.
1.5 inches
When the concrete contains aggregate larger than allowed for the slump test, the large aggregate must be ____.
Removed by wet sieving the sample over 1.5 inch sieve
The mold for making the slump test is in the shape of ____.
The frustum of a cone
The height of the slump mold is___.
12 inches
The interior surface of the slump mold is allowed to have minor irregularities. T/F
False
For use in the slump test, the end or both ends of the tamping rod must be ____.
Rounded to a hemispherical tip
The sample of concrete for use in making the slump test must be obtained in accordance with ASTM Standard.
C172, Standard Practice for Sampling Freshly Mixed Concrete
The slump mold should be in a dry condition before beginning the test. T/F
False
The surface on which the slump mold will be placed must be ___.
Flat, level, moist, nonabsorbent, and free of vibration.
The slump mold is filled in ___ layers.
3
Each layer should fill approx ___ the volume of the mold.
1/3
The approx concrete depth (in vertical distance) after placing the first layer is ____, and the second layer is ____.
2 5/8 in. 6 1/8 in.
What is the specified number of roddings for each layer?
25
How deep should the tamping rod penetrate into each layer?
Rod each layer through its depth and into the previous layer approx 1 inch.
When rodding the bottom layer, the tamping rod must be ___ to uniformly distribute the strokes.
Slightly inclined
What must be done if the concrete drops below the top of the slump mold while the top layer is being rodded?
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 ___.
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. T/F
False
When raising the slump mold, it should not be rotated or twisted. T/F
True
How much time is allowed for lifting the slump mold?
5 +/- 2 seconds
The measurement for slump is made from the top of the mold to what point of the concrete specimen?
The displaced original center of the top surface of the specimen.
The slump of the concrete is measured and reported to the nearest _____.
1/4 inch
How much time is allowed to conduct the slump test from beginning to completion?
2.5 minutes
