Quality Control (QC) vs. Quality Assurance (QA)

Intertek-PSI understands the importance of verifying the quality, durability, placement and performance of construction materials, particularly where public funds are concerned. Our quality assurance and quality control (QA/QC) services can help process, monitor, document, and test materials at any stage of the project, ultimately helping you avoid costly rework, scheduling delays and the premature failure of earthwork solutions, foundations, concrete, and pavement.

The terms quality assurance and quality control are often used synonymously and may be thought to be interchangeable, but there are distinct differences, and both are critical to the success of a project. The two work together as equally important parts of a quality management system (QMS).

Quality Control (QC) can be defined as the planning and systematic actions of a contractor to monitor, assess, and adjust materials production or placement to ensure that the final deliverable will meet the owner’s expectations and industry specifications. The QC system tests material characteristics and monitors plant and site activities that might impact quality, catching issues in a timely manner when corrective action can still be taken to prevent non-conforming materials from being used. A contractor’s QC system should address materials production, transportation and handling, field placement procedures, the calibration and maintenance of equipment, the activities required for sampling, testing and inspection and a plan to make timely adjustments and corrections to ensure compliance.

The owner or their construction management consultant is responsible for quality assurance (QA). A QA program establishes and/or approves laboratory accreditation and qualifications, independent assurance (IA), dispute resolution, and the contractor’s quality control procedures.

Intertek-PSI provides QA/QC field and laboratory testing, inspection and monitoring for:

Soils and Foundations

  • Soil Compaction Testing
  • Soil Classification Testing
  • Field Density Testing
  • Soil Stabilization
  • Concrete Testing
  • Foundation Bearing Capacity
  • Settlement Testing
  • Deep Foundation Testing


  • Cement Physical & Chemical Testing
  • Aggregate Quality
  • Gradation testing
  • Mix Temperatures
  • Compressive strength testing
  • Mix Design
  • Slump testing
  • Air content testing

Pavements (Soil & Aggregates, Concrete and Asphalt)

  • Aggregate Quality
  • Gradation testing
  • Compaction testing
  • Material Temperatures
  • Moisture content of aggregate
  • Nuclear density testing
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