GCC Quality Control & Inspection 3 — Questions and Answers
Question 1: Which type of weld inspection method uses high-frequency sound waves to detect internal defects without damaging the weld?
- Magnetic particle testing (MT)
- Liquid penetrant testing (PT)
- Radiographic testing (RT)
- Ultrasonic testing (UT) (Correct answer)
Correct answer: Ultrasonic testing (UT)
Ultrasonic testing uses high-frequency sound waves transmitted through the weld to detect internal discontinuities such as cracks, lack of fusion, and porosity.
Question 2: A QC inspector is reviewing a concrete batch ticket. Which piece of information is MOST critical for verifying mix design compliance?
- The plant's street address
- The water-to-cementitious materials (w/cm) ratio and total water added (Correct answer)
- The truck driver's license number
- The delivery ticket sequence number
Correct answer: The water-to-cementitious materials (w/cm) ratio and total water added
The water-to-cementitious materials ratio is the single most important factor controlling concrete strength and durability, so verifying it against the mix design is critical.
Question 3: What does the term 'first article inspection' mean in a construction quality context?
- A review of the first RFI submitted on the project
- Inspecting the first delivery truck of materials each morning
- The owner's first formal site walk after mobilization
- A thorough inspection of the first completed unit of repetitive work to set the standard for all subsequent work (Correct answer)
Correct answer: A thorough inspection of the first completed unit of repetitive work to set the standard for all subsequent work
First article inspection evaluates the first completed instance of repetitive work to confirm quality before mass production or installation proceeds.
Question 4: Under ACI 318, if the average of three consecutive compressive strength test cylinders falls below f'c, what action is required?
- Immediate demolition of all concrete placed that day
- No action needed if individual breaks exceed only 500 psi below f'c
- Investigation and potential coring of the in-place concrete to verify structural adequacy (Correct answer)
- Simply increase cement content in future pours with no further investigation
Correct answer: Investigation and potential coring of the in-place concrete to verify structural adequacy
ACI 318 requires investigation of the cause of low strength results and may require drilling and testing cores from in-place concrete to determine actual strength and structural adequacy.
Question 5: What is the primary purpose of maintaining a 'material traceability' system on a project?
- To schedule deliveries to minimize crane idle time
- To compare supplier pricing for future bid purposes
- To link installed materials to certifications, test reports, and batch numbers for accountability (Correct answer)
- To track material costs for accounting purposes only
Correct answer: To link installed materials to certifications, test reports, and batch numbers for accountability
Material traceability links physical installed materials to their mill certificates, test reports, and lot numbers, enabling accountability if a defect or failure is later discovered.
Question 6: A contractor is installing HVAC ductwork and QC review finds the installed gauge metal is lighter than specified. What is the correct quality control response?
- Proceed if the ductwork looks straight and properly supported
- Request a credit from the owner and allow the lighter gauge to remain
- Notify the inspector verbally and continue work
- Issue a nonconformance report and require the subcontractor to replace the non-compliant ductwork (Correct answer)
Correct answer: Issue a nonconformance report and require the subcontractor to replace the non-compliant ductwork
Non-compliant installed materials must be formally documented via an NCR and removed or corrected; verbal notification without documentation does not satisfy quality control requirements.
Question 7: Which organization publishes the reference standard most commonly used for testing and certifying construction materials in the United States?
- ICC (International Code Council)
- AGC (Associated General Contractors)
- OSHA
- ASTM International (Correct answer)
Correct answer: ASTM International
ASTM International publishes the standard test methods and material specifications most widely referenced in construction contracts for verifying material quality and performance.
GCC Quality Control & Inspection 3
Which type of weld inspection method uses high-frequency sound waves to detect internal defects without damaging the weld?