LABORATORY CALIFORNIA BEARING RATIO APPARATUS, MOTORISED AZA0912

Description

Importance of Motorised Operation in CBR Testing

The CBR test measures soil resistance to penetration by a standard plunger, expressed as a percentage of the load sustained by standard crushed rock. Standards such as IS 2720 (Part 16) and ASTM D1883 strictly require a penetration rate of 1.25 mm per minute.

The AZA0912 Motorised CBR Apparatus ensures:

• Constant Penetration Rate
  Motor and gearbox-controlled loading maintains the standard 1.25 mm/min rate throughout the test.

• Reduced Operator Fatigue
  Eliminates continuous manual cranking, allowing focus on accurate data recording.

• Improved Reproducibility
  Standardised loading significantly enhances test consistency and result reliability.

Working Principle of AZA0912 Motorised CBR Apparatus

1. Sample Preparation
   Soil is compacted or placed undisturbed in a standard 150 mm CBR mould. Surcharge weights simulate pavement load.

2. Test Setup
   The mould is positioned on the motorised loading frame. A 50 mm diameter penetration piston rests on the soil surface.

3. Measurement Arrangement

   • Load is measured using a calibrated proving ring with dial gauge.

   • Penetration depth is measured using a separate dial gauge with tripod.

4. Motorised Penetration
   The motor drives the piston downward at 1.25 mm/min, as per standards.

5. Manual Data Recording
   Load and penetration readings are recorded at standard intervals (0.5 mm to 12.5 mm).

6. Data Analysis
   Load–penetration curves are plotted, corrected, and CBR values at 2.5 mm and 5.0 mm penetration are calculated.

Key Features of AZA0912

• Heavy-Duty Motorised Loading Frame
  Precision-engineered frame with electric motor and reduction gearbox
  Penetration speed: 1.25 mm/min (fixed)
  Power supply: 230V AC, 50 Hz, Single Phase

• Calibrated Proving Ring
  Capacity options: 50 kN or 100 kN
  High-resolution dial gauge (typ. 0.002 mm LC)
  Supplied with calibration certificate

• Precision Penetration Dial Gauge
  Range: 25 mm
  Least count: 0.01 mm
  Supplied with sturdy tripod stand

• Standard Accessories

  • 50 mm hardened steel penetration piston

  • CBR moulds (150 mm dia × 175 mm height)

  • Spacer disc (148 mm dia × 47.7 mm height)

  • Slotted surcharge weights (2.5 kg, 5 kg, 10 kg)

  • Cutting collar and perforated base plate

  • Swell plate (where applicable)

• Robust Construction & Safety
  Heavy-duty steel construction with corrosion-resistant finish
  Limit switches for over-travel protection

Applications

• Pavement and highway design

• Quality control of subgrade, sub-base, and base materials

• Soil stabilisation studies

• Academic and geotechnical research laboratories

Standards Compliance

• IS 2720 (Part 16):1987 (Reaffirmed 2021)

• ASTM D1883

• BS 1377-4

Technical Specifications

Model: AZA0912
Product Type: Laboratory CBR Apparatus, Motorised
Country of Origin: Made in India

Loading Capacity: 50 kN or 100 kN
Penetration Speed: 1.25 mm/min
Penetration Piston: 50 mm diameter, hardened steel
Penetration Measurement: Dial gauge, 25 mm travel, 0.01 mm LC
Load Measurement: Proving ring with dial gauge
Power Supply: 230V AC, 50 Hz, Single Phase

FAQ – AZA0912

Q: What is the main advantage of AZA0912 over manual CBR units?
A: The motorised system guarantees a constant penetration rate, improving accuracy and reproducibility.

Q: Is data recording automatic?
A: No. Penetration is motorised, but readings are manually recorded from dial gauges. (Fully automatic systems are available in higher models such as AZA0913.)

Q: What soil types can be tested?
A: Both laboratory-compacted and undisturbed soil specimens.

Q: Why is CBR testing critical?
A: It determines pavement layer thickness based on soil bearing capacity, directly influencing pavement life and safety.