Our Services

CBR Testing Services & Plate Load Testing

Specialists in Plate Load test and CBR test services for the UK Civil Engineering and Construction industries. Providing fast and efficient Site testing services nationwide at a fixed rate.

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Site Investigation

We provide expert-level Site Investigation services across the UK. Helping UK construction companies identify the bearing capacity and settlement characteristics of soils.


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Laboratory and Chemical Analysis

We can offer analysis of most compounds within 24 hours and utilise the largest independent laboratory in the UK providing multiple solutions for the testing of soil, water, and other matrices.

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CBR Testing Services

At Site Testing Services Nationwide, we provide CBR tests for the UK construction and civil engineering industries. For over 20 years our team of experts has effectively provided effective and accurate CBR test results nationwide.

Utilising the leading technology and equipment our CBR tests provide our clientele with fully indicative assessments as well as a clear analysis of each result.

  • Nationwide Coverage
  • Two Decades of Expertise
  • 100% Reliable Analysis
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Plate Load Testing Services

Our expert team can provide accurate and reliable Plate Load Testing services to help you make informed decisions about the design and construction of your project.

With a variety of science-backed services designed to deliver great results that exceed industry standards.

  • Fast Results
  • Fixed Rate
  • Industry-leading Experts

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Our Nationwide Coverage

We provide fast and efficient testing services at construction and civil engineering sites across the UK.

With sites based across the country from Land’s End to the John O’Groats, we understand that conditions vary depending on the location of your site.

Our years of experience allow us to tailor our range of services to suit your development needs.

  • Fast & Efficient Service
  • Expert Industry Knowledge
  • Same Day Results
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What is CBR Testing?

A CBR Test (California Bearing Ratio test) is a procedure used to evaluate the sub-grade ground strength in the design and construction of roads and pavements.

Engineers and construction companies must know the penetration resistance of the soil. This is to determine how strong the ground, base course, and substrates are, before undertaking any construction project.

The California State Highway Department invented the test, naming it the California Bearing Ratio (CBR test.) Today CBR Testing is specified in BS1377: Part 9: 1990: Soils for civil engineering purposes.

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Professional Processes

CBR Testing is a test to evaluate the amount of force needed to penetrate the soils using a circular plate.

Digital dial indicators measure the settlement of the plate in increments of .25mm up to 1.5mm to create a graph and plot the results. This will calculate the CBR value and “K” value that engineers are required to evaluate and implement into their design.

Highly recommended

I have used STS on various schemes over the last few years and have always found them to be professional, give great service and will go out of their way to accommodate should difficult situations arise. I would recommend highly to anyone to use their services.

Tony Pate

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When is a CBR Test Required?

In general, the process should be undertaken whenever you want to find out how stable is the subsoil and the base material of a particular area.

CBR testing is an integral part of pavement design, typically conducted for the design of highways and roads.

Determining the CBR value provides adequate information required to determine the highway thickness, the suitable road pavement designs, parking designs and loading designs, along with how to establish a temporary foundation.

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Is a high CBR considered good or bad?

A higher California Bearing Ratio (CBR) value indicates that the material is harder. It is important to note that when it comes to CBR values, what is considered “good” or “bad” very much depends on the project requirements as well as the intended use for the soil.

CBR values indicate the strength of the soil in question, identifying its overall suitability to be used as a subgrade for pavements or roads.

Clay, for example, has a typical CBR of less than 10%, indicative of very weak soil. Sands and silts have a value of around 10%-30%, which may require some stabilisation.

Stable soils typically have a CBR value of 30-80% which are deemed suitable for road construction, with the capability to support heavy traffic.

A high-quality sub-base could range from 80% to 100%. These soils are usually gravel or crushed stones, which can support heavy loads. These soils are best utilised under any form of heavy traffic surface, such as roads or motorways.


How is CBR calculated?

In essence, a CBR test is a penetration test. To calculate the CBR value a cylinder plunger is pressed into the soil at a speed of 1.25mm per minute. The plunger tests and measures the pressure required to penetrate a soil sample.

This measurement is compared with the pressure needed to achieve an equal penetration of a high-quality, standard crushed rock material. As a result, the harder the surface, the higher the CBR value.

CBR tests are suitable for soils that have a maximum particle diameter of 20 mm. A CBR test is usually carried out at surface level or a depth of between 500-1000m. Each CBR test is typically conducted in 20-30mm intervals, along the proposed construction centreline.

When it comes to a typical site with prepared surfaces, a CBR test is usually undertaken multiple times in one day by a single operator. A provisional result is often available on-site in this instance.


How much does a CBR test cost?

The cost for a CBR test can vary widely depending on many different factors. Geographical location, service provider and the specific test required (laboratory or field) can all play a part in determining the overall cost.

Type of Test:

  • Laboratory Tests: Lab tests are generally less expensive because they take place in a controlled setting. This also means less mobilisation of equipment is required, which leads to fewer costs incurred.
  • Field Tests: Field tests are typically more expensive due to the possible complexity of conditions on site as well as equipment transportation.

Samples Ordered: The number of samples required can affect the overall cost. Multiple tests can be ordered at the same time to reduce the cost of each sample. This is due to more efficiency when it comes to handling and processing multiple samples.

Additional services: If additional services are required, this can play a factor in the overall cost. Preliminary site investigations, soil sampling, and specific reporting requirements may increase the overall cost for example.

Location: Prices may vary depending on the region, due to differences in travel distances and labour rates.

At Site Testing Services Nationwide, we provide a fixed rate for each CBR test conducted, regardless of the location. As a leader in CBR test services, we can provide our support nationwide with multiple locations across the UK. For this reason, we can offer highly competitive fixed rates across the board.

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