Quality Control, Inspection, and Testing
Domain focus
This domain tests inspection and testing across pre-construction, construction, and post-construction phases, including acceptance criteria and investigation of failed results.
Core rules
- Pre-construction QC includes substrate evaluation, chloride and carbonation testing, moisture testing, mockups, and approval of materials and procedures.
- During construction, verify surface preparation, cleanliness, SSD condition, bonding-agent open time, mix water, batch tickets, placement temperature, consolidation, and curing.
- Post-construction inspection includes visual examination, hammer sounding for delamination, and bond testing. ASTM C1583 measures tensile bond strength by pull-off.
- Non-destructive methods include rebound hammer (ASTM C805), ultrasonic pulse velocity (ASTM C597), half-cell potential (ASTM C876), cover meters, ground-penetrating radar, and infrared thermography.
- Material tests include slump (ASTM C143), air content (ASTM C231), compressive strength (ASTM C109), and chloride content (ASTM C1218 or C1152).
- A failed test is investigated, not simply repeated. Check specimen preparation, cure age, test alignment, substrate condition, and whether the result is statistically valid.
Worked example
A pull-off test on a cementitious patch fails below the specified bond strength. Reasoning: first verify the core was cut through the repair and into substrate, the loading rate was correct, and the test age was adequate. Inspect the failure surface: if failure is in the substrate, the repair may be stronger than the concrete; if at the bond line, investigate dust, dry substrate, bonding-agent open time, or curing. Do not accept the repair until the cause is corrected and retesting is representative.
Traps
- Testing epoxy or cementitious repairs before adequate cure.
- Coring that damages the bond interface.
- Treating a hammer-sounding result as quantitative bond strength.
- Sampling chloride contamination only at the surface.