At Simtec Materials Testing Ltd, our expert team has the experience and specialist testing capacity to carry out both Plate Bearing Tests and CBR (California Bearing Ratio) Tests utilising the latest technology.
These are the two most popular and reliable soil plate load tests used within the construction of buildings and roads. Both are used to determine the bearing capacity of soil and often work together hand-in-hand. However, it is important to understand the differences between the two.
What is a Plate Bearing Test?
A Plate Bearing Test, or Plate Load Test, is a geotechnical engineering test used to establish the strength and bearing capacity of large particles or hard/coarse underlying materials. This helps Engineers to determine the properties and suitability of soil for foundations, such as buildings and roads before any planned or proposed work can be carried out.
During the test, a steel plate is loaded at a consistent rate, with readings taken every minute until the detectable movement of the plate has stopped. The Plate Bearing Test allows for a greater surface area test than that of a traditional CBR Test.
From this data, we are then able to assess the force, amount of penetration, and time it takes for a rigid plate to penetrate the surface.
When would I choose a Plate Bearing Test?
Plate Bearing testing could establish the suitability of large or coarse materials in the following areas:
- Strength and durability of building materials such as concrete or steel
- Load bearing capacity of a structure such as a bridge or a dam
- Investigate behaviour and performance of soil beneath the existing structure
- Assess the integrity of a structure after a natural disaster
- Load distribution beneath a structure
- Inspect the foundation or underside of a structure
What is a CBR (California Bearing Ratio) Test?
The California Bearing Ratio Test, or CBR Test, is more commonly used to assess the strength and suitability of fine materials, as opposed to coarse materials, where the particle sizes are no greater than 20mm.
To understand the CBR value, our specialist California Bearing Ratio Testing Engineers must first evaluate how much force is required to penetrate a particular section of soil. This is carried out by a penetration plunger. When our Engineers have established the pressure required to penetrate the soil, this is then divided by the amount of force required for similar soil.
When would I choose a California Bearing Ratio Test?
CBR testing could establish the suitability of fine materials for use in the following areas:
- Strength and durability of building materials such as concrete or steel
- Load bearing capacity of a structure such as a bridge or a dam
- Investigate behaviour and performance of soil beneath the existing structure
- Assess the integrity of a structure after a natural disaster
- Load distribution beneath a structure
- Inspect the foundation or underside of a structure
- Test the stability of a structure during construction
- Evaluate the safety of a structure for public use
How to calculate CBR from a Plate Bearing Test
The result of the plate load test gives an equivalent CBR value. To calculate the CBR (California Bearing Ratio) from a Plate Bearing Test, our Specialist Engineers need to determine the load applied to the plate, the area of the plate, and the thickness.
This can be calculated as follows:
- Determine the load applied to the plate
- Determine the area of the plate
- Determine the thickness of the soil sample
- Calculate the CBR by dividing the load applied to the place by the area of the plate – multiplied by the thickness of the soil sample
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.
Our Plate Bearing Tests & CBR (California Bearing Ratio) Tests
Simtec Materials Testing Ltd offer CBR and Plate Load Testing for clients nationwide who require load bearing information on subbase materials when undertaking road pavement design.
We are a UKAS-accredited* company for delivering both tests in accordance with, BS1377-9:1990 and IAN73/06 standards.
Not sure which test you require? Our team of experts are ready and waiting to discuss a range of packages for any new project.