Density, Yield, and Air Content of Concrete

The diameter of the tamping rod used in this test method is ____

5/8 in

What is the required shape of the tamping end of the rod?

Round hemispherical

What is the required minimum frequency of the vibrator used in this test method?

9000 vibrations/min

The outside diameter or side dimension of the vibrating element must be at least ___ but no greater than ___

.75 in, 1.5 in

T/F A plastic container can be used for the measure in this test method.

False

What is the minimum thickness for a glass or acrylic strike off plate?

½ in

What is the minimum thickness of a metal strike off plate?

¼ in

What is the specified weight of the mallet used on measures that are 14 L or smaller?

1.25 lbs (600 g)

Measures other than air meter bowls used for this test must conform to Test Method ___

C29

Air meter bowls used for this test must conform to Test Method ___ and be calibrated for volume according to Test Method ____

C231, C29

The concrete sample must be obtained in accordance with what ASTM Practice?

C172

What method of consolidation must be used when the slump is greater than 75 mm (3 in)

Rodding

What method of consolidation must be used when the slump is less than 25 mm (1 in)

Vibration

If rodding is the method of consolidation being used, the measure must be filled in how many layers?

3

For a measure of 14 L (0.5 ft³ ), what is the required number of strokes of the tamping rod for consolidation of each layer?

25

When rodding the middle and top layers, the tamping rod should penetrate into the layer below approximately ___

1 in

If vibration is the method of consolidation, the measure must be filled in ___ approximately equal layers.

2

If after consolidation of the final layer, the concrete level is 13mm (1/2 in) above the top of the measure, what should be done?

remove the excess

After consolidation of the final layer, an excess of concrete ___ above the top of the measure is considered optimum.

1/8 in

After completing the strike off procedure, what must be done before weighing the measure and sample?

clean off excess concrete

Density of concrete

NET mass of concrete divided by volume of measure

Net mass of concrete

mass of measure plus sample - mass of empty measure

Yield

Mass/Density

Air content

[(T-D)/T] x 100

Theoretical Density

Mass / Volume