ATT Soundness & Durability Testing 2

Question 1

In the sodium sulfate soundness test (ASTM C88), what is the required soaking temperature of the solution?

Accepted Answer

18 ± 1°C (64 ± 2°F)

Answer

ASTM C88 requires the sodium sulfate solution to be maintained at 18 ± 1°C (64 ± 2°F) during the soaking period.

Question 2

How many cycles of immersion and drying are typically specified in the ASTM C88 soundness test?

Accepted Answer

5 cycles

Answer

ASTM C88 specifies 5 cycles of alternating immersion in sulfate solution and oven drying.

Question 3

When calculating the weighted percent loss in the sulfate soundness test, what information is used as the weighting factor?

Accepted Answer

The percent retained on each sieve before testing

Answer

The weighted percent loss uses the percentage of material originally retained on each sieve as the weighting factor for each size fraction's loss.

Question 4

Which of the following best describes why magnesium sulfate is sometimes used instead of sodium sulfate in ASTM C88?

Accepted Answer

It provides a more severe test with higher percent losses

Answer

Magnesium sulfate produces higher percent losses and is considered a more severe soundness test than sodium sulfate.

Question 5

After the final drying cycle in ASTM C88, aggregate particles are washed over a sieve that is what fraction of the original test sieve size?

Accepted Answer

One-half of the original sieve opening

Answer

Particles are washed over a sieve with an opening one-half the size of the sieve on which they were originally retained to determine loss.

(ATT) ACI Aggregate Testing Technician Practice Test