CBR Test in Sarawak
California Bearing Ratio (CBR) testing in the laboratory and in situ for road designers and contractors across Sarawak.
Common Problems on Road Jobs
Pavement design needs a design CBR
Pavement design needs a design CBR before the drawings are fixed. Laboratory CBR results give the measured subgrade strength the designer uses to set layer thicknesses.
Subgrade wetter than expected
The subgrade is wetter than expected and soaked strength is the real question. Four-day soaking identifies swell characteristics and bearing loss under seasonal saturated conditions.
Borrow material approval
Borrow material must be approved before it is hauled. Laboratory compaction and CBR tests show whether the fill meets the specification before it is placed on site.
In-situ subgrade verification
The consultant asks for in-situ CBR on the prepared subgrade. On-site penetration testing verifies that the compacted subgrade achieves the required strength in place.
Subgrade variation along alignment
Results vary along the alignment across cut and fill sections. Testing along the route locates low-strength stretches requiring soil replacement or stabilisation.
Results in a formal report
Results needed in a formal report for consultant approval and QA compliance. Each test includes load-penetration curves, moisture measurements and documented CBR values.
CBR Tests We Carry Out
| Test Name | What It Tells You | Standard / Method |
|---|---|---|
| Unsoaked CBR, top and bottom, including sample preparation | Bearing strength at moulding moisture | BS 1377 Part 4 |
| Soaked CBR, top and bottom, including sample preparation | Bearing strength after soaking | BS 1377 Part 4 |
| In-situ CBR | Bearing strength of the prepared layer in place | BS 1377 Part 9 |
How It Works
Booking & Details
Book with location, material and test type.
Sampling or Site Setup
Samples collected or in-situ test set up on site.
Testing
Samples are tested to standard geotechnical methods.
Formal Reporting
You receive a formal test report.
Standards & Reporting
Testing follows Malaysian JKR specifications and standard geotechnical test methods. Final test reports are endorsed by a Professional Engineer (PEPC).
Read more in our FAQ →Related Services & Reading
Related services: Geotechnical testing, In-situ field testing, DCP test in Sarawak.
From our Technical Journal: California Bearing Ratio testing explained, Plate bearing test guide.
Frequently Asked Questions
What is a CBR test?
A California Bearing Ratio (CBR) test measures the penetration resistance and bearing strength of subgrade soil or road base material compared to a standard crushed rock reference.
What is the difference between soaked and unsoaked CBR?
Unsoaked CBR tests the soil at moulding moisture content. Soaked CBR submerges the specimen in water for four days before testing to measure swell and bearing strength under saturated conditions.
What is an in-situ CBR test?
An in-situ CBR test measures penetration resistance directly on the prepared subgrade or road base layer on site using a mechanical jack reacted against a loaded vehicle.
Do you come to site in Sarawak?
Yes, our team carries out in-situ testing and sampling on site; see service areas.
How do I book?
Use the booking form; give location, material details and required test type.