Field CBR Test Machine
STANDART: BS 1377:9; 1924:2; ASTM D4429; UNI 10009; NF
LT-S0185 Field CBR Test Apparatus
LT-S0185/1 Mechanical Jack with Spherical Seat | 50 kN
LT-S0185/2 Extension Sleeves
LT-S0185/3 Datum Bar| 2 Leg
LT-S0185/4 Annular Surcharge Weight| 4,5 Kg
LT-S0185/5 Slotted Surcharge Weight | 4,5 Kg
LT-S0185/6 Slotted Surcharge Weight | 9 Kg
LT-S0185/7 Conversion Frame
The Field CBR Test Apparatus is designed to determine the in-situ California Bearing Ratio (CBR) of subgrade, sub-base and soil materials directly under field conditions. The system uses a 50 kN mechanical jack and 50 kN load ring to apply and measure the penetration load, while a 30 mm analog dial indicator with 0.01 mm graduation monitors piston penetration.
- In-situ CBR testing: Evaluates soil bearing behaviour directly at the test location.
- 50 kN loading capacity: Mechanical jack provides controlled loading up to 50 kN.
- 50 kN load ring: Measures the load applied during penetration.
- CBR penetration piston: Transfers the test load directly to the soil surface.
- Analog displacement measurement: 30 mm range with 0.01 mm graduation.
- Magnetic dial gauge holder: Allows easy positioning of the displacement indicator.
- Extension sleeves: Includes 2 × 102 mm, 1 × 305 mm and 1 × 610 mm extensions.
- Two-leg datum bar: Provides an independent displacement reference.
- Surcharge weights: 4.5 kg annular, 4.5 kg slotted and 9 kg slotted weights are available.
- Mechanical operation: Loading is applied manually through the hand-operated jack.
- Field applications: Suitable for subgrades, sub-bases and selected base materials.
- Laboratory conversion: LT-S0185/7 conversion frame allows the system to be adapted for mechanical laboratory CBR testing.
- External dimensions: 240 × 1630 × 230 mm.
- Approximate weight: 65 kg.
- Product code: LT-S0185.
| Product Code | Product Name / Description |
| LT-S0185 | Field CBR Test Apparatus |
| LT-S0185/1 | Mechanical Jack with Spherical Seat, 50 kN Capacity |
| LT-G8015 | Load Ring, 50 kN |
| LT-S0150/1 | CBR Penetration Piston |
| LT-G8001 | Analog Dial Indicator, 30 × 0.01 mm |
| LT-G8001/1 | Adjustable Dial Indicator Holder, Magnetic Base |
| LT-S0185/2 | Extension Sleeves — 2 × 102 mm, 1 × 305 mm, 1 × 610 mm |
| LT-S0185/3 | Two-Leg Datum Bar |
| LT-S0185/4 | Annular Surcharge Weight, 4.5 kg |
| LT-S0185/5 | Slotted Surcharge Weight, 4.5 kg |
| LT-S0185/6 | Slotted Surcharge Weight, 9 kg |
| LT-S0185/7 | Conversion Frame |
What Is a Field CBR Test Apparatus?
The Field CBR Test Apparatus is used to determine the California Bearing Ratio of soils and pavement materials directly under in-situ conditions.
Unlike a laboratory CBR test, where a prepared specimen is compacted inside a mould, the field method measures the penetration resistance of the material in its existing condition.
The LT-S0185 is particularly suitable for assessing subgrade, sub-base and selected base-course materials during road construction and field investigations.
50 kN Mechanical Loading System
The test system uses a 50 kN capacity mechanical jack with a spherical seat.
The operator applies the test load manually through the jack while the 50 kN load ring measures the force transferred to the penetration piston.
This mechanical arrangement allows the test to be carried out without an electrical power supply, making the equipment practical for remote or temporary field locations.
CBR Penetration Measurement
The standard CBR penetration piston is driven vertically into the prepared test surface.
A 30 mm analog dial indicator with 0.01 mm graduation measures the penetration movement. The adjustable magnetic holder allows the gauge to be positioned relative to an independent reference system.
The operator records load values at the required penetration levels and uses these measurements to calculate the CBR value.
Extension Sleeves and Datum Bar
The LT-S0185 system includes extension components that allow the loading arrangement to be adapted to the available reaction structure.
The extension set consists of:
- 2 × 102 mm sleeves
- 1 × 305 mm sleeve
- 1 × 610 mm sleeve
A two-leg datum bar provides an independent reference for displacement measurement. This helps separate piston penetration from movement of the loading assembly itself.
Surcharge Weight Options
The system can be used with different surcharge weights to reproduce the required test conditions.
Available weights include a 4.5 kg annular surcharge weight, a 4.5 kg slotted surcharge weight and a 9 kg slotted surcharge weight.
These components allow the surface loading condition around the penetration piston to be adjusted according to the selected test procedure.
BS 1377-9:2025
The current British reference is BS 1377-9:2025.
BSI published this edition on 20 November 2025 and explicitly includes the in-situ California Bearing Ratio (CBR) test among the methods for evaluating vertical deformation and strength characteristics of soils.
For this product, this is currently the cleanest active standard reference for field CBR testing.
BS 1924-2:2025
The page also references BS 1924-2.
The current version is BS 1924-2:2025, which covers sample preparation and testing of unbound, hydraulically bound and stabilized materials used in civil engineering. It remains current and includes soil bearing-capacity and penetration-related testing within its scope.
This reference is most relevant where the field CBR equipment is used in connection with stabilized or treated materials.
ASTM D4429 Standard Status
LİYA’s current product page lists ASTM D4429.
However, ASTM officially lists ASTM D4429-09a as Withdrawn 2018 — No Replacement. The former method covered the determination of CBR of soil tested directly in place and was intended for subgrades, sub-bases and certain base-course materials.
Therefore, ASTM D4429 should not appear on the new page as a current compliance standard.
CNR UNI 10009 Standard Status
The existing LİYA page also references UNI 10009.
The official UNI record identifies CNR UNI 10009:1964 as withdrawn on 25 September 2008.
It should therefore be treated only as a historical or legacy CBR reference.
Laboratory CBR Conversion
The LT-S0185/7 Conversion Frame allows the mechanical field system to be adapted for laboratory CBR testing.
When combined with the mechanical jack, load ring, penetration piston and appropriate CBR mould equipment, the same loading components can be used in a laboratory configuration.
This provides additional flexibility for laboratories that require both field and mechanical laboratory CBR testing.
Field Soil Bearing Assessment
The LT-S0185 measures approximately 240 × 1630 × 230 mm and weighs around 65 kg.
Overall, the Field CBR Test Apparatus combines a 50 kN mechanical loading system, analog penetration measurement, surcharge weights and an independent datum reference to provide a practical solution for evaluating the in-situ bearing behaviour of soils and pavement materials.
