CPII Construction Inspection Techniques 2 — Questions and Answers
Question 1: When inspecting a concrete pour, at what point should an inspector collect a slump test sample?
- After the concrete has been placed in the forms
- At the point of discharge from the truck, after discarding the first portion (Correct answer)
- At the batch plant before loading
- At the end of the truck discharge when the drum is nearly empty
Correct answer: At the point of discharge from the truck, after discarding the first portion
Slump test samples must be taken at the point of discharge after the first portion is discarded to ensure a representative sample of the concrete being placed.
Question 2: Which type of non-destructive testing method uses high-frequency sound waves to detect internal flaws in structural steel?
- Magnetic particle testing
- Liquid penetrant testing
- Ultrasonic testing (Correct answer)
- Radiographic testing
Correct answer: Ultrasonic testing
Ultrasonic testing (UT) uses high-frequency sound waves that reflect off internal discontinuities, making it effective for detecting subsurface flaws in structural steel.
Question 3: An inspector observes that rebar spacing in a concrete wall form exceeds plan specifications by 2 inches. What is the correct course of action?
- Approve the placement since 2 inches is a minor deviation
- Document the deviation and issue a nonconformance report requiring correction before concrete placement (Correct answer)
- Allow concrete placement and note the deviation in the daily report only
- Immediately halt all site work and notify regulatory authorities
Correct answer: Document the deviation and issue a nonconformance report requiring correction before concrete placement
Any deviation from approved plans must be documented via a nonconformance report and corrected before proceeding with concrete placement to ensure structural integrity.
Question 4: What is the primary purpose of a proctor compaction test in earthwork inspection?
- To determine the bearing capacity of in-situ soil
- To establish the relationship between moisture content and maximum dry density for a soil (Correct answer)
- To measure the permeability of compacted fill
- To classify the soil type according to the Unified Soil Classification System
Correct answer: To establish the relationship between moisture content and maximum dry density for a soil
The Proctor compaction test establishes the optimum moisture content and maximum dry density, which serve as the reference standard for field compaction testing.
Question 5: During a pipeline trench inspection, the inspector finds that the bedding material placed below the pipe is clay rather than the specified granular material. What risk does this create?
- Increased installation speed that may cause worker safety issues
- Differential settlement and potential pipe joint separation or failure (Correct answer)
- Reduced trench width that violates OSHA requirements
- Excess stormwater infiltration into the trench
Correct answer: Differential settlement and potential pipe joint separation or failure
Clay bedding retains moisture and is susceptible to differential settlement, which can cause pipe joint separation, cracking, or structural failure over time.
Question 6: What does a core sample extracted from a completed asphalt pavement primarily allow an inspector to verify?
- Surface friction coefficient and skid resistance
- Lift thickness and degree of compaction (Correct answer)
- Aggregate gradation compliance only
- Pavement marking retroreflectivity
Correct answer: Lift thickness and degree of compaction
Pavement cores allow direct measurement of individual lift thicknesses and laboratory determination of in-place density to confirm compaction meets specification requirements.
Question 7: Which inspection technique is most appropriate for verifying the integrity of a completed concrete bridge deck after placement?
- Chain dragging to detect delaminations (Correct answer)
- Schmidt hammer rebound to measure surface hardness only
- Liquid penetrant testing for surface cracks
- Nuclear density gauge for moisture content
Correct answer: Chain dragging to detect delaminations
Chain dragging produces a hollow sound over delaminated areas, making it an effective, rapid, and low-cost method for identifying subsurface delaminations in bridge decks.
CPII Construction Inspection Techniques 2
When inspecting a concrete pour, at what point should an inspector collect a slump test sample?