Quality Control and Testing

Concrete quality control ensures the placed material meets the strength, durability, and workability specified.
Slump testing on delivery measures workability — concrete outside the specified range must be rejected.
Cube testing involves casting standard moulds that are cured and crushed to verify compressive strength.
Temperature monitoring of fresh concrete is needed for mass pours and in extreme weather conditions.
Air content testing is required for concrete specified with air entrainment for freeze-thaw resistance.
Cube samples must be taken at the frequency specified in the quality plan — typically one set per pour or load.
Cubes must be cured under controlled conditions to give representative strength results.
Non-conforming concrete — wrong strength, slump, or specification — must be reported and assessed by the engineer.
Delivery tickets must be checked against the order to confirm grade, cement type, and admixtures match.
All quality records must be retained for the handover file and maintained for the structure's design life.

Structural safety	Under-strength or non-conforming concrete compromises structural integrity and can lead to collapse.
Legal and contractual	Quality control testing provides documented proof that the concrete meets the design specification.
Early detection	Testing during the pour allows non-conforming concrete to be rejected before it is placed in the structure.

Do

Don't

Check every delivery ticket against the order for grade, cement type, and admixtures
Carry out slump tests on each load and reject concrete outside the specified range
Cast cube samples at the frequency required by the quality plan for each pour
Cure cubes in controlled conditions as specified in BS EN 12390-2
Monitor concrete temperature during mass pours and in hot or cold weather
Test air content where the specification requires air-entrained concrete
Report any non-conforming results to the engineer immediately for assessment
Label all cube samples clearly with date, load number, location, and grade
Retain all quality records including delivery tickets, test results, and assessments
Brief the pour team on the quality requirements before each concrete placement

DON'T accept concrete that does not match the delivery ticket specification
DON'T skip slump testing because the concrete looks acceptable on arrival
DON'T add water to the concrete on site to increase workability without authorisation
DON'T cast cubes from unrepresentative samples taken at the wrong time or location
DON'T cure cubes in uncontrolled conditions — it gives misleading strength results
DON'T ignore non-conforming test results — report them for immediate engineering review
DON'T pour concrete that has exceeded its specified working time or gone stiff
DON'T lose or misidentify cube samples — traceability to the pour location is essential
DON'T falsify quality records — the consequences for structural safety are severe
DON'T place concrete without checking it meets the specification for that element

See also: Concrete Pour Safety | Concrete Cube Testing Safety

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