The standard details the specifications for California Bearing Ratio (CBR) moulds and their associated components used in soil strength testing as outlined in IS 2720 (Part XVI). It defines the required dimensions, materials, fabrication, and marking protocols for moulds, cutting collars, base plates, spacer discs, weights, penetration plungers, and other related items. This ensures precision and uniformity in soil testing procedures within geotechnical and civil engineering applications.
Overview
The standard details the specifications for California Bearing Ratio (CBR) moulds and their associated components used in soil strength testing as outlined in IS 2720 (Part XVI). It defines the required dimensions, materials, fabrication, and marking protocols for moulds, cutting collars, base plates, spacer discs, weights, penetration plungers, and other related items. This ensures precision and uniformity in soil testing procedures within geotechnical and civil engineering applications.
Audience
Contents
Structure
Defines the materials, dimensions, construction, and marking requirements for CBR moulds and their accessories used in soil bearing ratio testing.
Details the size requirements and tolerance limits for mould components as per figures and IS tolerance standards.
Lists materials such as copper alloy, brass, phosphor bronze, mild steel, cast iron, with references to corresponding IS standards.
Outlines construction criteria including surface finish, plating, and assembly features for moulds, collars, base plates, and accessories.
Specifies mandatory markings including manufacturer identification, material type, manufacturing date, and optional ISI certification marks.
Describes dimensional and material specifications for spacer discs, adjustable stems, penetration plungers, stay rods, wing nuts, and washers.
Covers quality assurance measures including surface plating for corrosion resistance and tolerance compliance.
Explains the criteria and licensing conditions under which equipment can bear the ISI mark, ensuring compliance and quality.
Summarizes revisions to materials, dimensions, and accessory specifications, including referenced IS codes and tolerance updates.
Provides diagrams and figures depicting dimensions, assembly, and material designations for CBR moulds and accessories.
Frequently Asked
The standard recommends specific materials to ensure durability, precision, and resistance in CBR moulds and accessories. Typically, moulds and cutting collars are manufactured from copper alloy and brass respectively; base plates may be phosphor bronze or chrome-plated mild steel; spacer discs and handles are made of mild steel; weights are cast iron; adjustable stems and perforated plates use brass; penetration plungers and stay rods are mild steel with plating for corrosion resistance; wing nuts and washers are forged or cast steel with cadmium or chrome plating. These materials maintain dimensional stability and ensure consistent soil testing results.
The standard stipulates precise tolerances to maintain accuracy in soil testing. For instance, the internal diameter of moulds is set at 150 mm with a tolerance of ±0.5 mm; mould height is 175 mm ±1.0 mm; wall thickness is uniform, generally around 3 mm; base plates must have flatness within 0.1 mm; cutting collars are 50 mm ±0.5 mm in height; penetration plungers have a diameter of 50 mm ±0.02 mm. These tolerances ensure consistent sample volumes and reliable CBR test outcomes.
Compatibility is ensured by designing moulds and accessories with dimensions and tolerances that conform exactly to the requirements of IS 2720 (Part XVI), which governs CBR testing procedures. The standard references IS 2720 (Part XVI) explicitly and adheres to tolerance norms set by IS 2102-1969 to preserve interchangeability and precision. Additionally, the use of ISI certification marks confirms adherence to quality and conformity, guaranteeing that the equipment produces consistent and reproducible results aligned with the soil testing methodology.
Marking on CBR moulds and accessories must be clear and permanent, including the manufacturer's name or registered trademark, the type of material used, and the manufacturing date. Equipment may also bear the ISI Certification Mark if licensed, attesting to compliance with Indian Standards. These markings facilitate traceability, quality verification, and compliance with testing protocols.
Yes, the standard specifies that the cutting collar should be made of brass and preferably be of the same material as the mould, with two integral or welded ears for handling. It must fit flush with the mould at the lower end. The base plate is to be constructed from phosphor bronze or chrome-plated mild steel and designed with appropriate seating to align correctly with the mould and collar. These construction details ensure precise assembly and durability during testing.
Ask AI about any clause, requirement, or provision in IS 9669. Get instant, clause-cited responses powered by our indexed library.
Free tier includes 150 queries (50 AI + 100 Reference) · No credit card required