Product Code : MSI 23068

Product Description

The MSI 3068 California Bearing Ratio (CBR) Test Apparatus – Field Type is designed for determining the in-situ California Bearing Ratio of soils and pavement materials directly at construction sites. The apparatus is particularly useful for evaluating the load-bearing characteristics of subgrade and sub-base materials under actual field conditions.

Field CBR testing is especially applicable where the in-place density and moisture conditions are representative of service conditions, including soils with a degree of saturation of 80% or greater, and coarse-grained cohesionless materials whose strength is relatively unaffected by moisture variations.

The apparatus incorporates a 10,000 kg capacity mechanical screw loading jack, which can be mounted beneath a loaded truck or another suitable reaction arrangement. The applied load is transmitted through a 50 mm diameter penetration piston, while penetration is measured using a dial gauge and the applied load is measured using a calibrated proving ring.

The equipment is designed for field use and includes extension rods, connectors, a dial gauge support bridge and surcharge weights.

Key Features

• Designed for field CBR testing as per IS 2720 (Part XXXI):1969.

• Determines the in-situ bearing characteristics of subgrade soils.

• Heavy-duty mechanical screw loading jack of 10,000 kg capacity.

• Suitable for mounting beneath a truck or other reaction system.

• Standard 50 mm diameter penetration piston.

• Extension rods of different lengths for convenient field adjustments.

• Eight-piece connector set for assembling the penetration system.

• Dial gauge support bridge with adjustable clamp.

• Quick-release screw clamp for positioning the dial gauge.

• Annular and slotted surcharge weights.

• Compatible with high-sensitivity proving rings.

• Robust construction for site testing applications.

Technical Specifications

Model ; MSI 3068

Product Name : California Bearing Ratio Test Apparatus – Field Type

Standard : IS 2720 (Part XXXI):1969

Test Type : In-Situ / Field CBR

Loading Mechanism : Mechanical Screw Jack

Jack Capacity  : 10,000 kg

Jack Arrangement  : U-Bracket with Swivel Head

Penetration Piston  : 50 mm diameter

Extension Rods : Multiple lengths

Connector Set  : 8 Nos.

Dial Gauge Support Height  : 300 mm

Dial Gauge Support Base Width ; 450 mm

Support Bridge Length : 2 metres

Annular Surcharge Weight  : 5 kg

Slotted Surcharge Weight  : 5 kg each

Dial Gauge (Accessory)  ; 0.01 mm × 25 mm

Proving Ring (Accessory)  ; 5000 kg capacity

Standard Apparatus Components

1. Mechanical Screw Loading Jack

The apparatus is provided with a mechanical screw loading jack having a capacity of 10,000 kg. It includes a U-bracket and swivel head for applying penetration loads through a suitable reaction arrangement.

2. Penetration Piston

A steel penetration piston having a 50 mm diameter is provided. The upper end is threaded for connection with the proving ring assembly or extension rods.

3. Extension Rods

The extension rods are manufactured from machined steel tubing and are used as spacers between the proving ring and penetration piston.

The supplied extension rods comprise:

Length Quantity

5 cm : 2 Nos.

10 cm : Quantity to be confirmed

30 cm : 1 No.

50 cm : 1 No.

100 cm : 1 No.

4. Connector Set

A set of eight connectors is provided for coupling the penetration piston and proving ring assembly, either directly or through the extension rods.

5. Dial Gauge Support Bridge

The dial gauge support is manufactured from seamless steel pipe and features:

• Height: 30 cm

• Base width: 45 cm

• Bridge length: 2 metres

• Quick-release screw-type clamp

• Sliding and locking arrangement for convenient gauge positioning

6. Surcharge Weights

Component Specification Quantity

Annular Metal Weight : 5 kg, 250 mm dia, 53 mm central hole As specified

Slotted Metal Weight : 5 kg, 215–250 mm dia, 53 mm slot 2 Nos.

Accessories

The following accessories are available for the field CBR apparatus:

• Dial Gauge: 25 mm travel with 0.01 mm least count.

• High-Sensitivity Proving Ring: 5000 kg capacity, supplied with calibration chart and carrying case.

Applications

• Field California Bearing Ratio testing

• In-situ soil bearing capacity evaluation

• Highway and road construction projects

• Subgrade strength assessment

• Pavement design investigations

• Road embankment testing

• Geotechnical site investigations

• Construction quality control

• Civil engineering field laboratories

Advantages

• Enables direct evaluation of soil under existing field conditions.

• Avoids reliance solely on laboratory-remoulded specimens.

• Heavy-duty mechanical loading system suitable for field applications.

• Multiple extension rods accommodate different reaction-frame heights.

• Portable component arrangement for site use.

• Suitable for evaluating subgrade performance in pavement engineering.