CBR Testing: Ensuring Strong, Reliable Ground Conditions

When it comes to building durable roads, pavements, foundations, and commercial developments, understanding the strength of the ground is essential. 

What Is CBR Testing?

CBR Testing is a geotechnical method used to measure the strength and load-bearing capacity of soil and sub-base layers. Originally developed for road construction, it is now widely used across all sectors where ground conditions play a critical role in structural stability.

The CBR value represents how well the soil can resist penetration. The higher the value, the stronger the material—and the more suitable it is for supporting loads such as road surfaces, slabs, or foundations.

Why CBR Testing Matters

Poor ground conditions can lead to surface deformation, cracking, settlement, and even structural failure. CBR Testing allows you to:

• Confirm soil suitability for highways, car parks, temporary haul roads, and building platforms

• Determine required thickness of sub-base and pavement layers

• Reduce risk and cost by identifying weak ground before construction

• Meet design specifications and regulatory requirements

• Plan remedial actions such as stabilisation or reinforcement

With accurate data, you can optimise your design and avoid expensive over-engineering or unexpected groundworks.

Our CBR Testing Services

Perry Testing Ltd offers both in-situ and laboratory-based CBR testing, depending on your project needs.

In-Situ CBR Testing

Ideal for assessing on-site ground conditions directly. Our experienced technicians use portable equipment to measure CBR values on formation level, sub-grade layers, or compacted materials. Results can be provided the same day to keep your project moving.

Laboratory CBR Testing

When samples are taken to our accredited laboratory, we can provide highly controlled, accurate testing, including:

• Soaked and unsoaked CBR values

• Moisture content and density analysis

• Compaction characteristics

• Detailed reporting for engineers and design teams

When Is CBR Testing Required?

You may need CBR Testing for:

• Road and highway construction

• Car parks and forecourts

• Industrial yards and loading bays

• Housing developments

• Temporary construction roads or crane pads

• Rail and infrastructure projects

• Foundation design where soil strength is critical

CBR values help determine whether the ground is strong enough as-is or requires strengthening through stabilisation, imported aggregates, or other engineering solutions.