CBR Test: California Bearing Ratio Test

The CBR & Incremental Plate Load Test Explained:

Preliminary tests often need to be carried out before building of structures or new Highways can take place. These tests establish the load bearing of soils and indicate the stress load they can handle to understand if construction is viable, their aim is to replicate wheel loads for Highways and ground settlement and stability for structures.

To measure surface strength values, we offer two on-site services.
1. A California Bearing Ratio Test (CBR Test)
2. A Incremental Plate Load Test

Both services provide much-needed data about your site and can help decide on the plan of action before construction begins.

A CBR Test is primarily required to gather data for road pavement design, the CBR test provides results that give clear understanding for the stress load of the sub-grade however it is only suitable for areas where the particle size is no greater than 20mm. To test areas with particle sizes larger than 20mm an Incremental Plate Load Test is often carried out, the results from this can indicate if construction of structures is safe to do so.

Types of Testing

CBR Testing

A CBR value is usually represented as a percentage. A Clay usually achieves around 2% with compacted or undisturbed sands up to around 10%. A well compacted sub-base should achieve 30% CBR and above. For particle sizes larger than 20mm you will need to look for Plate Bearing Tests. CBR testing is rigorous and requires multiple tests across the site. Normally carried out at surface level or at depths of 500-1000mm, this test is usually repeated along the length of the proposed centreline of the carriageway. This gives you a good indication of the strength of your sub-base before any construction takes place.

A CBR value is usually represented as a percentage. A Clay usually achieves around 2% with compacted or undisturbed sands up to around 10%. A well compacted sub-base should achieve 30% CBR and above. For particle sizes larger than 20mm you will need to look for Plate Bearing Tests.

CBR testing is rigorous and requires multiple tests across the site. Normally carried out at surface level or at depths of 500-1000mm, this test is usually repeated along the length of the proposed centreline of the carriageway. This gives you a good indication of the strength of your sub-base before any construction takes place.

This standard test has been a mainstay of civil engineering since the 1930s. CBR testing can also be used to assess existing ground conditions to complete geotechnical investigations. This allows you to plan and fine-tune your project to any formation encountered during construction.

Incremental Plate Load Testing

The second test is the incremental plate load which is used to measure the vertical deformation and strength characteristics of the in-situ soil by assessing the force and amount of penetration and time taken for a rigid plate to penetrate Into the ground.

This test method is widely used when establishing the strength of crane bases, piling pads or crane outriggers, as well as foundations for building slabs or commercial building stanchion bases, to ensure the required loading can be achieved.

Simtec has successfully delivered services to the construction and civil engineering industry since 2007. We are proud of our high level of customer service and integrity and have a proven track record which has attributed to our growth within the sector. Contact us today, using the form, to find out more about our field testing services and how we can help you keep your project on track and within budget.

 

Simtec CBR Testing Services

Simtec Material Testing has the capacity to carry out CBR (California Bearing Ratio Testing) and Incremental Plate Load testing
throughout the UK. We are UKAS accredited for both tests in accordance with, BS1377-9:1990 and IAN73/06. Feel free to also visit our accreditations page. An indication of test results can be supplied the same day. Following this, test reports will be supplied in electronic format within a specified timescale.

Both methods of plate testing will require kentledge which is usually in the form of a 360-degree site excavator or similar Item of plant, available on-site provided by the client.

 

CBR Test on JCB

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Frequently Asked Questions

A CBR value is usually represented as a percentage. A Clay usually achieves around 2% with compacted or undisturbed sands up to around 10%. A well compacted sub-base should achieve 30% CBR and above. For particle sizes larger than 20mm you will need to look for Plate Bearing Tests.
By using Simtec a UKAS accredited testing organisation, results will be accepted by all UK Government agencies including Highways England and local authorities.
Weather does not adversely affect testing, however rain over a prolonged period will distort CBR values. Avoid testing when the surface is frozen or affected by frost and snow or is saturated.
Testing at each location typically lasts 30 mins. Individual test duration will vary according to the ground conditions.

The Simtec approach

Fast, accurate assurance when you need it.

We act as the grease-in-the-wheels of the construction industry, ensuring work progresses at pace with unnecessary costs avoided. Since 2007 we have established ourselves as the trusted name in construction materials testing, building a professional, practical and methodical business culture from the top down.

Our approach is simple – we believe shared knowledge is the foundation on which we all progress. That’s why we have documented and routinely share best practices with our partners and clients to minimise everyone’s exposure to risk.

Every contract we undertake is measured against the Simtec Optimum Compliance Benchmark –data consisting of best practice criteria, designed to help you achieve consistently high compliance approval and avoid cost of delay or remedial work. We’re proud that the integrity, rigour and safeguarding we provide has established Simtec as a trusted testing partner to firms across the UK’s construction sector.

Simtec Plate Load Bearing Testing

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