CCI Structural Inspection Methods 2 — Questions and Answers
Question 1: When inspecting a reinforced concrete beam, what is the primary concern regarding concrete cover over rebar?
- Aesthetic appearance of the finished surface
- Protection of steel from corrosion and fire exposure (Correct answer)
- Reduction of total concrete volume used
- Improvement of formwork removal ease
Correct answer: Protection of steel from corrosion and fire exposure
Adequate concrete cover protects embedded steel reinforcement from corrosion due to moisture ingress and provides fire resistance.
Question 2: Which test is used to evaluate the in-place compressive strength of hardened concrete non-destructively?
- Slump test
- Rebound hammer (Schmidt hammer) test (Correct answer)
- Air entrainment meter test
- Bleeding rate test
Correct answer: Rebound hammer (Schmidt hammer) test
The rebound hammer test measures surface hardness of hardened concrete, which correlates to estimated compressive strength.
Question 3: During structural steel erection inspection, what does a 'plumb' check verify?
- Horizontal levelness of beams
- Vertical alignment of columns (Correct answer)
- Weld bead profile quality
- Bolt torque value
Correct answer: Vertical alignment of columns
A plumb check verifies that steel columns are perfectly vertical within allowable tolerances specified in the project documents.
Question 4: A construction inspector notices a crack pattern in a masonry wall that is diagonal and runs from a window corner downward. This most likely indicates:
- Thermal expansion cracking
- Differential settlement of the foundation (Correct answer)
- Shrinkage during curing
- Overloading of the lintel above
Correct answer: Differential settlement of the foundation
Diagonal cracks emanating from openings such as windows are a classic indicator of differential foundation settlement.
Question 5: What is the purpose of a hydrostatic pressure test on a structural waterproofing membrane?
- To measure membrane thickness uniformity
- To verify the membrane resists water penetration under pressure (Correct answer)
- To check bond strength to the substrate
- To determine the membrane's fire rating
Correct answer: To verify the membrane resists water penetration under pressure
A hydrostatic pressure test confirms that the waterproofing membrane can resist water under sustained pressure without leaking.
Question 6: When inspecting anchor bolts for a steel column base plate, the inspector should verify:
- That bolts are painted to match the base plate color
- Bolt diameter, embedment depth, projection, and spacing per approved drawings (Correct answer)
- That grout is placed before bolt installation
- That bolts are installed without washers to allow adjustment
Correct answer: Bolt diameter, embedment depth, projection, and spacing per approved drawings
Anchor bolt inspection must confirm correct diameter, embedment depth, projection height, and layout spacing against the approved structural drawings.
Question 7: In post-tensioned concrete construction, what is a 'tendon bleed-off' and why is it significant?
- Loss of hydraulic fluid from the stressing jack, requiring recalibration
- Grout escaping from duct vents, confirming complete duct filling
- Unexpected strand elongation beyond calculated values
- Corrosion product seeping from anchorage zones indicating moisture intrusion (Correct answer)
Correct answer: Corrosion product seeping from anchorage zones indicating moisture intrusion
Tendon bleed-off refers to rust-stained water weeping from anchorage zones, indicating that moisture has reached the prestressing steel and corrosion is occurring.
CCI Structural Inspection Methods 2
When inspecting a reinforced concrete beam, what is the primary concern regarding concrete cover over rebar?