CBR Testing Machine
California Bearing Ratio (CBR) testing machine for evaluating subgrade and pavement layer strength per IS 2720 (Part 16).
NABL TC-14144·
ISO/IEC 17025:2017·
Lab ID NKM/EQ-8
The CBR Testing Machine measures the California Bearing Ratio — the load-penetration strength of subgrade, sub-base and base-course materials that governs flexible pavement thickness design. NKMPV's Accro-Tech machine runs soaked and unsoaked CBR at the standard 1.25 mm/min penetration rate per IS 2720 (Part 16).
What this equipment tests
- Soaked CBR value of subgrade soil (4-day soak)
- Unsoaked CBR value
- Load-penetration curves at 2.5 mm & 5.0 mm penetration
- CBR of granular sub-base (GSB) and base materials
Applicable Indian Standards
- IS 2720 (Part 16) — Laboratory determination of CBR
- IRC 37 — Guidelines for the design of flexible pavements
Related NABL testing services
Frequently asked questions
What is the CBR test used for?
CBR expresses subgrade/pavement-layer strength as a percentage of a standard crushed-stone value; it is the key input for flexible pavement thickness design under IRC 37.
Do you test soaked and unsoaked CBR?
Yes — both, with the standard 4-day soak for soaked CBR, per IS 2720 (Part 16).