Concrete Sampling Services

Testing concrete samples is a necessary requirement for most of the structural concrete in the UK, which must meet strict industry standards before it can be used. GSTL offers the 2 main concrete sample tests:

The British Standard specifies two procedures for fresh concrete sample testing: composite sampling and spot sampling.

Composite Sampling

Composite sampling involves one of our field technicians visiting the site and collecting scoops of concrete from different areas of the load midstream as it pours out of the cement mixer. Up to four portions of fresh concrete are collected and combined into a single composite sample, which is representative of the whole truck load. Our trained technicians follow industry best practices to ensure the sample is truly representative of the batch, to avoid any inaccuracies in the final concrete test results.

Concrete Mix

Spot Sampling

The most common method for concrete sample testing where there is a large amount of concrete and multiple mixer trucks being used, is spot sampling. Again, one of our qualified field technicians will be on-site to collect samples from the cement mixer. This method is quicker than composite sampling as scoops are collected from the initial discharge of concrete out of the mixer.

On collection, the samples are then protected from the elements and possible contamination and the concrete sample testing takes place on-site. Once the samples have been placed in cube moulds they are cured and compacted using a form of mechanical vibration and the cube’s compressive strength is measured and recorded.

Testing the strength of a concrete sample

Determination of Slump BS EN 12350-2

Our expert field technicians check the consistency of the concrete sample using an open-ended cone mould which holds 3 layers of fresh concrete. Each layer is tamped down 25 times and the top knocked off, before the cone is removed and the concrete upended. The depth the concrete has slumped is then carefully measured using a calibrated rule and the result recorded.

Benefits of Concrete Sample Testing

Concrete Sample Testing is an easy, efficient, and cost-effective way to gain a highly accurate reading of the compressive strength and unit weight of freshly mixed concrete. We ensure a representative sample of the fresh concrete is obtained for the Compressive Strength of Concrete Cubes, these cubic specimens will be tested back at the laboratory after curing to determine the strength of hardened concrete cubes (100-150mm). Commonly tested at 7 and 28 days after casting.

Benefits of Concrete Sample Testing include:

  • Essential for avoiding structural failure
  • Ensures proper batching and proportioning of the mix
  • Exposes any problems with the tested material
  • Maintains high production standards
  • Strength test can be used to inform construction operations
Preparing concrete samples for strength testing

GSTL support a wide range of sectors with on-site Concrete Sample Testing services, including construction, roads, retail, harbours, and housing.

Please don’t hesitate to get in touch with our friendly team if you have any questions or if you’d like to learn more about how you can use our testing services to help you successfully deliver your next project.