ATT Cheat Sheet 2026

The 30 highest-yield ATT facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. In the sand equivalent test (ASTM D2419), the purpose of the flocculating solution (calcium chloride) is to: → Cause clay and fine dust to flocculate and settle into a distinct layer
2. What is the maximum allowable lightweight pieces (coal and lignite) in fine aggregate per ASTM C33 for concrete subject to surface wear? → 0.5%
3. What is the PRIMARY purpose of continuing education requirements in Los Angeles Abrasion Testing for ATT professionals? → Maintaining current knowledge and competency as the field evolves
4. Which ASTM standard covers the test method for flat particles, elongated particles, or flat and elongated particles in coarse aggregate? → ASTM D4791
5. Which sieve must be placed beneath the No. 200 sieve to prevent damage during the ASTM C117 wash procedure? → No. 100 sieve
6. Why is determining void content in aggregates important? → To estimate cement requirements
7. When testing for lightweight pieces per ASTM C123, the test result is expressed as: → Percentage by mass of lightweight pieces
8. When combining results of the ASTM C117 wash test with a dry ASTM C136 sieve analysis, how is the total percent passing the No. 200 sieve reported? → The wash test value is used as it captures more fines than dry sieving
9. Chert with a bulk specific gravity less than 2.40 is considered a deleterious substance in coarse aggregate because: → It has poor freeze-thaw durability and causes pop-outs
10. Which test method determines the specific gravity of coarse aggregates? → ASTM C127
11. Which equipment is essential for performing a mechanical sieve analysis? → Mechanical sieve shaker
12. Which ASTM standard is used to determine lightweight pieces in aggregate (such as coal and lignite)? → ASTM C123
13. Which standard of practice is MOST important for ensuring quality in Aggregate Sampling & Reduction? → Following evidence-based protocols while adapting to specific circumstances
14. In Fine Aggregate Quality Tests, what is the FIRST step a ATT professional should take when encountering a new case or situation? → Conduct a comprehensive assessment and gather all relevant information
15. Which of the following is a valid sampling location for aggregate in transport? → From a stopped conveyor or truck bed.
16. When sampling from a stockpile, what is the most important principle to follow? → Collect from various depths and locations.
17. How should a field sample be reduced to testing size? → Using a mechanical splitter or quartering method.
18. The particle index test (ASTM D3398) measures aggregate quality based on: → Particle shape and surface texture using void content
19. What is the purpose of performing a sieve analysis on aggregates? → To determine particle size distribution.
20. After washing, the retained aggregate must be dried to a constant mass at what temperature range? → 110 ± 5°C (230 ± 9°F)
21. In Aggregate Sampling & Reduction, what is the FIRST step a ATT professional should take when encountering a new case or situation? → Conduct a comprehensive assessment and gather all relevant information
22. Which type of material is primarily removed during the ASTM C117 washing procedure that could not be removed by dry sieving alone? → Clay coatings and silt adhering to larger particles
23. Which standard of practice is MOST important for ensuring quality in Unit Weight & Voids Testing? → Following evidence-based protocols while adapting to specific circumstances
24. Which ASTM standard covers the test method for clay lumps and friable particles in aggregates? → ASTM C142
25. Which ASTM standard governs the sand equivalent value test for coarse-grained soils and fine aggregates? → ASTM D2419
26. What is the PRIMARY purpose of continuing education requirements in Soundness & Durability Testing for ATT professionals? → Maintaining current knowledge and competency as the field evolves
27. A particle classified as 'flat and elongated' in ASTM D4791 has a ratio of its maximum dimension to its minimum dimension exceeding: → 5:1
28. Why is SSD condition critical in concrete mix design? → To account for water absorption accurately
29. In ASTM C117 (material finer than No. 200), after washing the aggregate is dried to constant mass at what temperature? → 110 ± 5°C
30. Which characteristic of aggregate makes the washing test particularly critical for evaluating concrete aggregate quality? → Presence of clay and silt that weaken the aggregate-paste bond