6.4 Quality Inspection & Testing

Quality Control (QC) is the physical execution of the quality plan. It relies on rigorous inspection, testing, and documentation to ensure the final product matches the contract documents.

Submittals as the First QC Step

Long before physical work begins, QC starts with the submittal process. Submittals (shop drawings, product data, material samples) require the contractor to explicitly state what they intend to procure and install. The review of submittals by the design team and CM ensures that the proposed materials conform to the specifications. Catching an error during the submittal phase costs nothing but time; catching the same error after the material is installed results in massive rework costs.

The Three-Phase Inspection System

Originally developed by the U.S. Army Corps of Engineers (USACE) and the Naval Facilities Engineering Command (NAVFAC), the Three-Phase Control System is widely considered the gold standard for construction QC and is heavily tested on the CCM exam. It applies a structured approach to every definable feature of work (DFOW).

1. Preparatory Phase

This phase occurs before any physical work begins on a specific task. Its goal is to ensure everything is ready for a successful installation.

• Review applicable specifications and drawings.
• Verify all submittals for the work are approved.
• Check that the required materials and equipment are on-site and in good condition.
• Verify that the work area is ready (e.g., preceding work is complete and accepted).
• Discuss construction methods, safety hazards, and QC testing requirements with the foremen and crews.
• Construct Mock-ups: Building a physical sample of the work (e.g., a 10x10 section of brick facade) to establish an agreed-upon standard of acceptable workmanship.

2. Initial Phase

This phase occurs when the work first begins (typically when a representative sample of the work has been completed).

• Inspect the initial work to ensure it matches the approved mock-up and specifications.
• Verify that the crews understand the required standards and are executing the work safely and correctly.
• Resolve any differences in interpretation of the plans early, before the crew installs a massive quantity of defective work.
• Repeat this phase if the crew changes or the quality of work starts to slip.

3. Follow-Up Phase

This phase occurs daily while the work is ongoing.

• Conduct continuous, routine inspections to ensure the work continues to meet the standards established in the Initial Phase.
• Verify that required testing is occurring at the specified frequencies.
• Document the daily inspections in the QC reports.
• Culminates in a final inspection of the definable feature of work before it is covered up by the next trade.

Inspection and Testing Methodologies

QC testing verifies material properties and system performance. The CM must understand the two broad categories of testing:

Destructive Testing (DT): The physical test destroys the sample, rendering it unusable for the actual project.

• Examples: Breaking concrete cylinders in a compression machine to verify psi strength; pulling structural steel welds apart to test tensile strength; cutting a core sample out of an asphalt road to check density.

Non-Destructive Testing (NDT): The test evaluates the properties of a material, component, or system without causing damage, allowing the item to be used in the final project.

• Examples: X-ray (radiography) or ultrasonic testing of steel welds; using a Schmidt hammer for estimating concrete strength; magnetic particle testing; thermal imaging of electrical panels.

Managing Non-Conformance

Despite the best prevention efforts, defects will occur. The mechanism for handling these is the Non-Conformance Report (NCR).

An NCR is a formal document issued (usually by the Contractor's QC Manager or the CM) when a specific item or process fails to meet the contract requirements.

The NCR process typically follows these steps:

1. Identification: The defect is discovered, and work on that specific element is halted.
2. Documentation: The NCR is generated, clearly identifying the location, the nature of the defect, and the specific contract clause violated.
3. Proposed Disposition: The contractor proposes a solution. The main types of disposition are:
   • Rework: Bring the item into total compliance with the original specifications.
   • Repair: Fix the item so it functions as intended, even if it doesn't strictly meet the original spec (requires Engineer of Record approval).
   • Use-As-Is: Accept the defect as it is, usually accompanied by a financial credit to the owner (requires Engineer of Record and Owner approval).
   • Reject/Scrap: Demolish the item and start over completely.
4. Approval: The Designer of Record and Owner approve the disposition.
5. Verification and Close-Out: The contractor executes the fix, and the QC Manager (and CM) inspects the fix to verify compliance, officially closing the NCR.