Fingertips
Easily access helpful, in-depth information on all things concrete construction—right at your fingertips.
Consistence tolerance – slump test
Consistence, measured using the slump test (BS EN 12350-2), is either specified as a class or target. Although a supplier will endeavour to provide the required value or range, deviations in production and sampling apply. The following tables give the maximum allowable deviation based on a spot sample taken from the initial discharge of a ready-mixed concrete truck.
| Class | Slump range | Max. allowable deviation on range limit (mm) |
| S1 | 10 – 40 | 0 – 60 |
| S2 | 50 – 90 | 30 – 110 |
| S3 | 100 – 150 | 80 – 170 |
| S4 | 160 – 210 | 140 – 230 |
Due to lack of sensitivity of slump test values less than 10mm or greater than 210mm, it recomended to only use the test for slump ≥10mm and ≤210mm
| Target slump (mm) | Max. allowable deviation on target value (mm) |
| ≤ 40 | ± 30 |
| 50 – 90 | ± 40 |
| ≥ 100 | ± 50 |
Based on BS 8500-1
The Concrete Society
Slump test apparatus
Become a Member
The Concrete Society is here to guide and support you every step of the way
- Technical resources and expert guidance
- Industry news and leading magazines
- An Independent team of in-house Technical Advisors
- Join a vibrant community from across the concrete supply chain