Benkelman Beam Device
STANDART: AASTHO T256-77, CNR N141
LT-AS0900 Benkelman Beam Device
The Benkelman Beam Device measures the vertical deflection and rebound of pavement surfaces under vehicle wheel loading. Its lightweight aluminium beam, dial indicator and mechanical measuring system provide a practical solution for field evaluation of flexible pavement behaviour.
- Pavement deflection measurement: Measures vertical pavement movement under loaded vehicle wheels.
- 250 cm beam length: The long beam allows the measuring tip to be positioned between the vehicle tyres.
- 4:1 fulcrum ratio: Transfers pavement movement to the dial indicator with mechanical amplification.
- Dial indicator measurement: Allows the operator to monitor pavement rebound during the test.
- Aluminium construction: Provides a lightweight yet durable structure for field applications.
- Adjustable supports: Help position the apparatus securely on the pavement surface.
- Field testing design: Suitable for road, pavement and rehabilitation assessment work.
- Wooden carrying case: Protects the beam and accessories during transport and storage.
- 16 kg weight: Supports easier transportation between measurement locations.
- Standards support: Liya Test lists AASHTO T256-77 and CNR N141 for the LT-AS0900.
| Product Code | Product Name | Beam Length (cm) | Fulcrum Ratio | Weight (kg) |
| LT-AS0900 | Benkelman Beam Device | 250 | 04:01 | 16 |
What Is a Benkelman Beam Device?
The Benkelman Beam Device measures pavement deflection caused by vehicle wheel loading. The instrument is mainly used for field evaluation of flexible road surfaces. It allows operators to observe how the pavement responds and rebounds as a loaded vehicle moves away from the test position.
Pavement deflection provides useful information about structural behaviour and existing road condition. Therefore, road authorities, contractors and pavement laboratories can use the results when evaluating maintenance and rehabilitation requirements. Liya Test supplies the LT-AS0900 as an aluminium beam complete with a dial indicator and accessories.
Benkelman Beam Test Procedure
During testing, the measuring tip is positioned on the pavement between the tyres of the loaded vehicle. The beam remains supported outside the main loaded area.
As the vehicle moves forward, the pavement begins to recover from the applied wheel load. The dial indicator records the corresponding vertical movement. This allows the operator to determine pavement rebound deflection under controlled field conditions.
FHWA identifies AASHTO T256 as a reference method for pavement deflection measurement.
250 cm Beam and 4:1 Fulcrum Ratio
The LT-AS0900 uses a beam approximately 250 cm long. This length makes it easier to position the measuring tip beneath the loaded axle while keeping the indicator and support system accessible to the operator.
The mechanical beam uses a 4:1 fulcrum ratio. Surface movement at the measuring tip is therefore transferred mechanically to the dial indicator, allowing relatively small pavement deflections to be observed clearly. Liya Test publishes both the 250 cm length and 4:1 ratio for this model.
Lightweight Aluminium Construction
The beam is manufactured from aluminium alloy. This construction combines field durability with relatively low weight.
The complete LT-AS0900 weighs approximately 16 kg, making it easier to transport between test locations. A wooden carrying case is supplied to protect the beam, dial indicator and associated components during storage and transportation.
Pavement Evaluation Applications
The Benkelman Beam Device is suitable for road condition surveys, rehabilitation studies and pavement quality control. Field teams can use the instrument to compare deflection behaviour at different locations along a pavement section.
Repeated measurements can help identify sections that show higher deformation under similar loading conditions. The results can then support broader pavement assessment programmes together with other structural and surface investigations.
Pavement Deflection Testing According to Standards
Liya Test lists AASHTO T256-77 and CNR N141 for the LT-AS0900 Benkelman Beam Device. Current industry references also associate Benkelman Beam apparatus with pavement deflection measurement under vehicle wheel loading.
Overall, the LT-AS0900 Benkelman Beam Device combines a 250 cm aluminium beam, 4:1 mechanical ratio, dial indicator and portable field design. Therefore, road laboratories and field teams can evaluate pavement deflection in a practical and repeatable manner.
