Practice Test GeeksACI (American Concrete Institute Certification) Practice Test
← All ACI Certification Flashcard Decks

Strength Testing Technician Flashcards

7 cards from real ACI Certification practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 7 Strength Testing Technician flashcards as text

  1. A concrete cylinder intended for compressive strength testing was inadvertently allowed to surface-dry before testing. What must be done per ASTM C39?

    Answer: Re-wet the specimen and allow it to re-soak before testing

    ASTM C39 requires specimens to be in a moist condition at the time of testing; if dried, they must be re-wetted and allowed to soak to restore proper moisture.

  2. Which piece of information is NOT typically required on a concrete cylinder identification tag used in the field?

    Answer: Exact mix design proportions by weight

    Exact mix design proportions are on the batch ticket, not the cylinder tag; date/time, load ID, and placement location are the standard tag requirements.

  3. Per ASTM C31, after the initial curing period, standard-cured specimens must be stored in water or a moist room at what specified nominal temperature?

    Answer: 73°F (23°C)

    Standard curing per ASTM C31 requires specimens to be maintained at 73 ± 3°F (23 ± 2°C) in water or a moist room after the initial field cure.

  4. What is the primary purpose of making both field-cured and standard-cured cylinders from the same concrete placement?

    Answer: To evaluate the adequacy of curing and protection applied in the field

    Comparing field-cured to standard-cured cylinders reveals whether field curing and protection are achieving adequate in-place concrete strength.

  5. Per ASTM C617, how long must a sulfur mortar cap be allowed to harden before the capped cylinder can be tested?

    Answer: 2 hours

    ASTM C617 requires that sulfur mortar caps be allowed to harden for a minimum of 2 hours before a load is applied to the specimen.

  6. When a single 28-day compressive strength test result falls below the specified f'c, what is the first step per ACI 318 acceptance criteria?

    Answer: Determine whether the result is more than 500 psi below f'c and whether overall acceptance criteria are still met

    ACI 318 acceptance criteria evaluate whether any single result is more than 500 psi below f'c — one low test does not automatically require rejection until the full criteria are assessed.

  7. A technician measures a cylinder's diameter twice at mid-height and gets 5.96 inches and 6.00 inches. To what precision and value should the diameter be recorded for the strength calculation?

    Answer: 5.98 inches (nearest 0.01 inch)

    ASTM C39 requires diameter to be recorded to the nearest 0.01 inch (0.25 mm) as the average of the two measurements: (5.96 + 6.00) / 2 = 5.98 inches.