CTQP Structures Inspection 5 — Questions and Answers
Question 1: In CTQP structures inspection, a 'critical finding' requires the inspector to:
- Document and include it in the next scheduled report
- Notify the responsible authority immediately and restrict or close the bridge if warranted (Correct answer)
- Flag it for the next in-depth inspection cycle
- Consult a materials laboratory before any action
Correct answer: Notify the responsible authority immediately and restrict or close the bridge if warranted
Critical findings pose immediate safety risk and require prompt notification and possible load restriction or bridge closure, not deferred action.
Question 2: Which AASHTO element condition state best describes a concrete column with moderate cracking, minor spalling, and no exposed rebar?
- Condition State 1
- Condition State 2 (Correct answer)
- Condition State 3
- Condition State 4
Correct answer: Condition State 2
Condition State 2 represents minor to moderate defects that do not yet expose or jeopardize primary reinforcement.
Question 3: When inspecting a timber pile bent, which defect is considered most structurally significant?
- Weathered surface checks running along the grain
- Section loss at the mud line due to decay (Correct answer)
- Minor insect galleries on the pile cap face
- Staining from tannin leaching
Correct answer: Section loss at the mud line due to decay
Decay at the mud line (the waterline/soil interface) causes the greatest section loss at the most critically loaded point, directly reducing load capacity.
Question 4: An inspector measures a bridge deck with a chain drag and hears a hollow sound over a 4 ft × 6 ft area. The most probable cause is:
- ASR gel accumulation near the surface
- Delamination between the concrete and the rebar plane (Correct answer)
- Freeze-thaw scaling of the wearing surface
- Longitudinal cracking from shrinkage
Correct answer: Delamination between the concrete and the rebar plane
A hollow sound from chain drag indicates delamination, a horizontal separation plane typically forming just above the top rebar mat due to rebar corrosion or thermal cycling.
Question 5: Under FHWA coding, a bridge component rated '4' on the NBI condition scale is described as:
- Failed condition — out of service
- Poor condition — advanced deterioration of primary structural elements (Correct answer)
- Fair condition — all primary structural elements are sound
- Good condition — some minor problems
Correct answer: Poor condition — advanced deterioration of primary structural elements
NBI rating 4 (Poor) indicates advanced deterioration or section loss in primary structural elements but the bridge remains in service with possible load posting.
Question 6: During inspection of a steel truss bridge, the inspector finds a lacing bar on a built-up compression chord is completely severed. The correct action is to:
- Record the defect and schedule a follow-up inspection in six months
- Treat it as a critical finding and notify the bridge owner immediately (Correct answer)
- Apply a temporary patch weld and continue the inspection
- Reduce the bridge rating by one NBI point and continue
Correct answer: Treat it as a critical finding and notify the bridge owner immediately
A severed lacing bar on a compression member compromises the effective slenderness ratio and is a critical structural defect requiring immediate notification.
Question 7: Which condition is the primary indicator that a pot bearing has lost its elastomeric fluid (silicone) and requires replacement?
- Rust staining around the base plate perimeter
- Lateral displacement of the piston beyond design limits
- Fluid extrusion visible around the piston rim seal (Correct answer)
- Cracking of the anchor bolts
Correct answer: Fluid extrusion visible around the piston rim seal
Fluid exuding around the piston rim seal indicates seal failure and loss of the confined elastomeric fluid that provides the bearing's rotational capacity.
CTQP Structures Inspection 5
In CTQP structures inspection, a 'critical finding' requires the inspector to: