Practice Test GeeksCCIL - Canadian Council of Independent Laboratories Practice Test
← All CCIL Flashcard Decks

Concrete Compressive Strength Testing Flashcards

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

Read the first 7 Concrete Compressive Strength Testing flashcards as text

  1. According to ASTM C39, what is the required rate of loading for compressive strength testing of cylindrical concrete specimens?

    Answer: 0.15 to 0.35 MPa/s (20 to 50 psi/s)

    ASTM C39 specifies a loading rate of 0.15 to 0.35 MPa/s (20 to 50 psi/s) during the final phase of loading.

  2. What fracture pattern in a cylindrical concrete specimen indicates a well-centered load with good end condition?

    Answer: Type 1 — cone fracture with no cracking through ends

    Type 1 (cone fracture) indicates uniform load distribution and satisfactory end conditions per ASTM C39 fracture pattern classifications.

  3. When using sulfur mortar capping for concrete cylinders, what is the minimum time the cap must cure before testing?

    Answer: 30 minutes

    Sulfur mortar caps must cure for a minimum of 30 minutes before the specimen is tested per ASTM C617 requirements.

  4. A 4×8 inch concrete cylinder yields a compressive strength of 4,250 psi. What correction factor is applied relative to the standard 6×12 inch cylinder?

    Answer: Multiply by 1.06

    Per ASTM C39, 4×8 inch cylinders may yield approximately 106% of the strength of 6×12 inch cylinders, requiring a correction factor of about 1.06.

  5. What is the maximum allowable departure from perpendicularity of the end surface of a concrete cylinder to its axis before testing?

    Answer: 0.50 degrees

    ASTM C39 allows a maximum departure from perpendicularity of 0.50 degrees (approximately 0.5% of diameter) for cylinder end surfaces.

  6. Which curing condition for standard-cured concrete cylinders is required per ASTM C31 prior to transportation to the lab?

    Answer: Maintain between 16°C and 27°C (60°F to 80°F) and protect from moisture loss

    ASTM C31 requires initial curing between 16°C and 27°C with protection from moisture loss until cylinders are transported to the lab.

  7. If two cylinders from the same sample set yield strengths of 3,820 psi and 3,540 psi, what is the percent difference and is it within ASTM C39 acceptable limits?

    Answer: 7.3% — within the 8% limit; average is reportable

    The difference is 280 psi / 3,820 psi ≈ 7.3%, which is within the ASTM C39 guideline of 8% between duplicate cylinders.

How this page was made: written with AI tools and published by Nathan Beja, founder of Practice Test Geeks, who is responsible for its content. Exam facts are checked against the official sources listed below. Not reviewed by a subject-matter expert. Editorial policy

Sources & references

Exam facts on this page (fees, format, dates, passing scores) are checked against these official sources; the date is our last check. Editorial policy

  1. ccil.com — Eligibility, renewal, score validity, test delivery, exam format, time limit · verified Oct 2026
Concrete Compressive Strength Testing Flashcards — CCIL Study Cards with Answers