Concrete Identity-Testing Sampling Guidance

The Building and Construction Authority (BCA) issued a circular on 1 September 2026 recommending a standardised minimum sampling rate for identity testing of concrete compressive strength. The circular applies to construction-industry practice where identity testing is performed and refers users to clause B.2(2), Annex B of SS EN 206. BCA says the guidance reflects the certification and quality-assurance maturity of Singapore's ready-mixed-concrete plants, while supporting more sustainable construction through fewer materials used for testing and less manpower (BCA, 1 September 2026).

Recommended minimum sampling rates

The circular recommends one sample per 100 m³ for the first 400 m³ of concrete cast, one sample per 200 m³ for the subsequent volume up to 2,500 m³, and 15 samples for volumes above 2,500 m³. For bored piles, the recommendation is at least one sample per pile. Each sample should consist of at least four cube specimens, with two cubes used for 7-day testing and two for 28-day testing. These are common baseline recommendations where identity testing is performed, not a statement that every project has identical testing needs (BCA, 1 September 2026).

Qualified Person discretion and additional cubes

BCA expressly preserves the Qualified Person's (QP's) responsibility to determine whether additional sampling is necessary based on engineering judgement, project complexity or specific quality concerns. Higher sampling rates may be appropriate for critical structural elements such as transfer beams, long cantilevers, long-span beams, deep foundations or heavily loaded elements. Additional cubes may also be needed for prestressed-concrete strength verification before load transfer, formwork striking-time decisions, concrete-quality concerns, random verification tests, or special concretes such as high-strength, lightweight or self-compacting concrete (BCA, 1 September 2026).

Cube size and interpretation boundary

The circular recommends and encourages the use of 100 mm cube specimens for conformity and identity testing where appropriate, noting that SS 544-1 permits them and that the identity criteria for 100 mm and 150 mm cubes are the same. BCA states that a 150 mm cube contains more than three times as much concrete as a 100 mm cube, creating material and transport benefits when the smaller specimen is suitable. The circular is a testing-rate and specimen guidance document; it does not replace the QP's engineering judgement, the applicable Building Control Regulations or the standards governing the specific project (BCA, 1 September 2026).