Concrete testing is an imperative part of the quality control process for concrete used across construction. By evaluating the physical and mechanical properties of concrete, you can ensure it meets project specifications and quality and durability requirements, and complies with the relevant British and European standards.
How concrete is tested
Testing depends on the type of concrete. Fresh (wet) concrete is tested as a standard quality check, with tests usually taking place on site. Hardened concrete is also tested for quality assurance, and to assess its current condition, structural safety, and durability to reduce the risk of failure (e.g. cracking).
Test methods for fresh concrete
The following tests can be used to check if the concrete meets the project’s requirements. They all take place on site:
- Slump/flow test – to measure consistency and workability.
- Air test – Conducted to verify the effectiveness of added air-entraining admixtures. This ensures the concrete achieves the necessary freeze-thaw resistance, making it essential for exposed applications such as external pavements, runways, and yards.
- Plastic density – checks the volume and weight of the concrete is correct.
- Temperature – to monitor cement hydration and reduce the risk of cracking.
Other fresh concrete tests take place in laboratories:
- Cube (compressive strength) testing – a standard test for all pours to ensure the concrete meets the standard for quality control: BS EN 12390 . Samples are taken on site and tested in the lab at 7 and 28 days for strength compliance.
- Setting time – Evaluated after mixing to determine the initial and final hardening phases, which is critical for informing your placement schedule. Because setting times vary significantly depending on the specific concrete mixture, ranging anywhere from one to eight hours, this testing ensures you know exactly what to expect prior to the concrete arriving on site,
- SmartRock – Our wireless concrete sensor, SmartRock, complements traditional cube testing by monitoring temperature and strength gain every 15 minutes for up to 60 days. By delivering the same reliable strength data directly to your phone, it eliminates the wait for lab results and gives you valuable time back on site.
Niche tests are available for specific concrete applications requiring specialised performance, such as deep ground foundations and piling. These include:
- Bleed testing: Determines the potential rate of settlement of heavy materials within the mix, which can cause excess water to rise and pool on the concrete's surface.
- Viscosity testing: Assesses the flowability of the concrete mixture, ensuring the material can be placed efficiently and meets the specific structural demands of your project.
Test methods for hardened concrete
Like fresh concrete, hardened concrete is tested as part of routine quality control. It’s also used to monitor and review its durability to prevent the risk of structural failures. Cube testing is the primary test method used on this type of concrete. If concrete cubes fail, most commonly due to poor site practice, such as a lack of early-age curing or the unauthorised addition of extra water on site, further diagnostic testing is carried out. These include:
- Ultrasonic pulse testing – Operating like a radar system within the hardened material, this non-destructive test helps identify the exact location of internal reinforcement and detects hidden structural flaws, such as internal voids or holes.
- Rebound hammer testing – this tests the hardness of the surface and is generally accepted as being a guide to the concrete’s strength.
- Moisture testing – if there’s a resin on top of concrete, a moisture test is done to make sure it’s ready to receive the final coat/final covering.
- Flexural and tensile strength – Rather than being a response to failure, this laboratory testing evaluates the concrete's bending and pulling strength. It is used to consult with project designers and confirm that the supplied mix meets their assumed structural specifications.
In a worst-case scenario, if these initial diagnostic tests are unable to determine the cause of the failure, a core sample of the concrete is drilled for further extensive testing.
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The importance of concrete testing
According to the MPA, over 90 million tonnes of concrete (both ready-mixed and precast) is consumed in a typical year in the UK. It’s one of the pillars of British infrastructure, used to build the foundations of the houses we live in, buildings we work from, and roads and pavements we use to get around.
When concrete doesn’t meet the required standards, there is a higher chance the structure will fail. It can lead to problems, like project delays, putting people’s lives in danger and damaging the reputation of a business. Common problems with low-quality concrete include:
- Cracking
- Curling
- Efflorescence
- Scaling
- Delamination
As such, the need for high-quality concrete can’t be overstated.
Concrete technical information
Explore technical information about our concrete solutions and find answers to common questions to ensure your project’s success.
Standards and regulations that concrete testing services need to meet
In the UK, there are several standards that concrete testing services must meet:
BS EN 206 (and BS 8500)
‘Core’ standards which cover the mix design, production, strength, and quality of the concrete, as well as minimum and maximum temperatures.
BS EN 12350
The series of tests for fresh concrete.
BS EN 12390
The series of tests for hardened concrete.
Concrete testing accreditation
Testing laboratories in the UK that hold UKAS Accreditation show compliance with British standards (e.g. the Construction Products Regulation (CPR) ) and international standards (such as ISO 17025 for testing laboratories).
Our concrete testing services
Heidelberg Materials operates its own UKAS-accredited laboratories, testing samples in accordance with current European and British Standards and under third-party accreditation by the Quality Scheme for Ready-Mixed Concrete (QSRMC).
We supply these results directly to our national data centre to maintain the highest possible level of data integrity. To ensure rigorous and objective quality control, our area technical managers monitor the results specific to their individual regions. Meanwhile, our national team receives data from across all regions, allowing them to spot broader performance trends and identify any potential issues right at the source.
Visit our document download centre to view the certificates for our concrete products.
What we offer
- A national laboratory that is fully equipped to provide testing services in accordance with British and European standards, plus regional laboratories in London and Manchester
- QSRMC accredited laboratories (all)
- A United Kingdom Accreditation Service (UKAS) accredited laboratory in Chipping Sodbury
- On-site sampling and testing service
- Collection and testing service for site-manufactured samples
- Concrete cube testing service (which can also measure consistency and air content)
- Expertise and advice from our technical team
- CPD-approved presentations available on request
- A hands-on facility at our evoHub Greenwich site, focused on sustainability-led product training and demonstrations
All of our concretes hold the following certifications:
How to collect concrete for tests
The following instructions are based on BS EN 12350 requirements.
Fresh concrete
- Check you’ve got the necessary equipment (non-absorbent containers, a shovel, and a trowel) and ensure it’s all clean to prevent contamination. The containers shouldn’t be wet, but they can be damp.
- Take samples in increments from the middle of the batch (after the first 10%, before the last 10%).
- Move the containers through the entire width of the stream or divert the chute to collect a full-width sample.
- Pour all samples into a clean container - for example, a wheelbarrow - then mix with a clean shovel to create a single sample.
- Use damp burlap to cover the sample. This prevents it from getting wet or drying out.
Hardened concrete
Two methods are primarily used to test hardened concrete.
- For new construction projects, fresh concrete samples can be collected on-site and placed into moulds (e.g. a 100mm cube or cylinder). They’re cured in a controlled environment for a set number of days, before getting transported to a dedicated laboratory where they undergo tests to determine their strength. This is an example of a non-destructive testing method.
- For concrete within an existing structure, drilling can be carried out to obtain a sample. It’s a destructive concrete testing method and, as such, would be a last resort, so the holes must be repaired to ensure structural integrity. The samples are checked for defects before undergoing a series of tests to measure performance.
Further support
To learn more about concrete testing, please contact our concrete technical support teams using the details below:
North: northtechnicalvetting@uk.heidelbergmaterials.com | 0330 678 1305
Central: centraltechnicalvetting@uk.heidelbergmaterials.com | 0330 678 1306
South: southtechnicalvetting@uk.heidelbergmaterials.com | 0330 678 1307
London: londontechnicalvetting@uk.heidelbergmaterials.com | 0330 678 1308
For other technical information or guides about concrete, please head to our concrete knowledge hub.