ATT Sieve Analysis & Gradation 2

Question 1

According to ASTM C136, what is the correct order of sieves when stacking them for a sieve analysis?

Accepted Answer

Largest opening at the top, pan at the bottom

Answer

Sieves are stacked with the largest opening at the top and progressively smaller openings below, with the pan at the bottom to catch material passing the finest sieve.

Question 2

What is the fineness modulus (FM) of a fine aggregate if the cumulative percentages retained on the standard sieves are: No.100=95, No.50=80, No.30=55, No.16=30, No.8=10, No.4=2?

Accepted Answer

2.72

Answer

FM = (95+80+55+30+10+2) / 100 = 272/100 = 2.72; fineness modulus sums cumulative percent retained on the six standard sieves divided by 100.

Question 3

When performing a washed sieve analysis per ASTM C117, after washing the sample over the No. 200 sieve, the material retained must be:

Accepted Answer

Dried to constant mass in an oven at 230±9°F (110±5°C)

Answer

After washing, the retained material is oven-dried to constant mass at 110±5°C (230±9°F) before performing the dry sieve analysis.

Question 4

The nominal maximum size of an aggregate is defined as:

Accepted Answer

The sieve size one step larger than the first sieve to retain more than 10%

Answer

Nominal maximum size is the smallest sieve opening through which the entire amount of aggregate is permitted to pass, which is one sieve size larger than the maximum size.

Question 5

A sieve is considered overloaded during a sieve analysis when:

Accepted Answer

The mass of material retained exceeds the limits specified in ASTM C136 for that sieve size

Answer

ASTM C136 specifies maximum mass limits per unit area for each sieve size; exceeding these limits causes particles to stack and prevents accurate separation.

(ATT) ACI Aggregate Testing Technician Practice Test

(ATT) ACI Aggregate Testing Technician Practice Test

ATT Sieve Analysis & Gradation 2