ATT Sampling Aggregates 2

Question 1

When sampling aggregates from a conveyor belt, how many approximately equal increments must be taken to constitute one sample according to ASTM D75?

Accepted Answer

At least 3 increments

Answer

ASTM D75 requires a minimum of three approximately equal increments taken from the full cross-section of the belt to constitute a field sample.

Question 2

Which piece of equipment is specifically recommended for obtaining a cross-sectional cut of aggregate from a moving conveyor belt?

Accepted Answer

A mechanical sampler frame

Answer

A mechanical sampler frame that spans the full belt width is recommended to capture a complete cross-sectional cut without bias.

Question 3

Why is sampling aggregate directly from a stockpile surface considered a poor practice?

Accepted Answer

Surface material has segregated and is not representative of the pile

Answer

Segregation causes coarser particles to roll to the outer edges and base of a stockpile, making surface samples unrepresentative of the bulk material.

Question 4

What is the primary purpose of reducing a large field sample of aggregate to a smaller test sample?

Accepted Answer

To obtain a specimen of manageable size that still represents the field sample

Answer

Sample reduction produces a test specimen small enough for laboratory equipment while preserving the same particle size distribution as the original field sample.

Question 5

Which ASTM standard governs the practice of reducing samples of aggregate to testing size?

Accepted Answer

ASTM C702

Answer

ASTM C702 covers the standard practice for reducing samples of aggregate to testing size using methods such as mechanical splitting or quartering.

(ATT) ACI Aggregate Testing Technician Practice Test

(ATT) ACI Aggregate Testing Technician Practice Test

ATT Sampling Aggregates 2