CCI Structural Inspection Methods 3 — Questions and Answers
Question 1: Which destructive testing method is used to determine the actual yield strength of reinforcing steel from a completed structure?
- Magnetic particle inspection
- Core sample testing with rebar extraction and tensile testing (Correct answer)
- Ultrasonic pulse velocity testing
- Radiographic imaging
Correct answer: Core sample testing with rebar extraction and tensile testing
Extracting rebar from a core sample and conducting tensile testing in a laboratory directly measures yield and ultimate strength of in-place reinforcing steel.
Question 2: A CCI inspector observes honeycombing in a formed concrete wall. What is the correct initial inspection action?
- Immediately reject the entire wall element
- Document location and extent, then notify the engineer of record for evaluation (Correct answer)
- Direct workers to patch the area with any available mortar
- Proceed without action if the honeycombing is less than 1 inch deep
Correct answer: Document location and extent, then notify the engineer of record for evaluation
The inspector must document and report honeycombing to the engineer of record, who determines whether repair, testing, or removal is required.
Question 3: What does the term 'effective depth' mean in reinforced concrete beam design and inspection?
- Total depth of the beam from top to bottom of section
- Distance from compression face to centroid of tension reinforcement (Correct answer)
- Depth of the concrete below the neutral axis
- Clear span length divided by the beam depth ratio
Correct answer: Distance from compression face to centroid of tension reinforcement
Effective depth (d) is the distance from the extreme compression fiber to the centroid of the tension steel, which determines the beam's moment arm.
Question 4: During wood-frame structural inspection, a 'cripple wall' refers to:
- A wall with reduced stud spacing due to heavy loads
- Short stud walls between the foundation and first floor framing (Correct answer)
- A wall with missing blocking at mid-height
- A non-load-bearing partition wall below the roof
Correct answer: Short stud walls between the foundation and first floor framing
Cripple walls are short stud walls between the foundation sill plate and the first floor, which are vulnerable to collapse in seismic events if not braced.
Question 5: When inspecting a welded moment frame connection, what does 'complete joint penetration (CJP)' indicate?
- The weld passes through the flange only and not the web
- The weld fuses completely through the full thickness of the base metal (Correct answer)
- The weld joint has been inspected and approved by the CWI
- The connection has achieved 100% of design moment capacity by bolting
Correct answer: The weld fuses completely through the full thickness of the base metal
A CJP weld penetrates and fuses the entire cross-section of the joint, providing full-strength connection required for moment frame performance.
Question 6: What is the significance of the 'k-zone' in wide-flange steel sections during inspection?
- The zone where shop primer must not be applied prior to welding
- The highly restrained area near beam-column flange/web intersection prone to weld cracking (Correct answer)
- The zone where field bolts replace shop bolts in erection sequence
- The region where lateral bracing must be attached per AISC requirements
Correct answer: The highly restrained area near beam-column flange/web intersection prone to weld cracking
The k-zone is a highly restrained area where the flange meets the fillet at the web, where weld heat-affected zone cracking has been a documented field problem.
Question 7: An inspector is checking prestressed concrete hollow-core plank. End bearing length is critical because:
- Insufficient bearing reduces fire resistance of the assembly
- Too little bearing can cause plank end to kick off the support under load (Correct answer)
- Bearing length determines the mortar joint thickness required
- Insufficient bearing length voids the manufacturer's warranty only
Correct answer: Too little bearing can cause plank end to kick off the support under load
If hollow-core plank does not have adequate bearing length on its support, the end can slide off and cause sudden structural collapse.
CCI Structural Inspection Methods 3
Which destructive testing method is used to determine the actual yield strength of reinforcing steel from a completed structure?