This standard defines the criteria for super sulphated cement, a hydraulic binder produced by combining granulated blast furnace slag, calcium sulphate, and a minor proportion of Portland cement or alternative lime sources. It addresses the material's composition, production methods, physical and chemical characteristics, testing protocols, packaging, and labeling requirements. The specification mainly serves manufacturers, distributors, and users, especially for applications demanding resistance to harsh environments such as marine structures and sulphate-rich soils.
Overview
This standard defines the criteria for super sulphated cement, a hydraulic binder produced by combining granulated blast furnace slag, calcium sulphate, and a minor proportion of Portland cement or alternative lime sources. It addresses the material's composition, production methods, physical and chemical characteristics, testing protocols, packaging, and labeling requirements. The specification mainly serves manufacturers, distributors, and users, especially for applications demanding resistance to harsh environments such as marine structures and sulphate-rich soils.
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Frequently Asked
According to the standard, the chemical limits for super sulphated cement are: Insoluble residue not exceeding 4%, magnesium oxide (MgO) capped at 10%, and sulphide sulphur limited to 1.5%. These values are determined by testing procedures defined in IS 4032:1985. The total chloride content is not fixed and must be agreed upon between purchaser and producer, with testing following IS 12423:1988. The cement typically contains at least 70% granulated blast furnace slag to ensure durability in aggressive environments.
Compressive strength is tested using mortar cubes with a 50 cm² face area, prepared by mixing one part super sulphated cement to three parts standard sand (IS 650:1966). Water content is calculated by (p/4 + 3)% of the combined cement and sand mass. Testing follows IS 4031 (Part 6):1988 procedures. The minimum compressive strengths required are 15 MPa at 72 hours, 22 MPa at 168 hours, and 30 MPa at 672 hours. These benchmarks ensure the cement's structural performance.
The cement must be packed in bags or drums, with the net mass per unit complying with specified tolerances outlined in Clause 8.2.1.1. The average net mass should not be less than the declared weight. Each package must be clearly marked with the product name 'Super sulphated Cement', net mass, manufacturer’s name and address, batch number or identification mark, manufacturing date, and the BIS certification mark where applicable. Additionally, a certificate indicating total chloride content must be provided as per amendments.
False set is assessed using the penetration test method described in IS 4031 (Part 14):1989. The false set ratio is calculated by dividing the final penetration after 5 minutes by the initial penetration after 20 seconds, expressed as a percentage, with a minimum threshold of 50%. If false set occurs, it is remedied by stirring before further testing setting times using the Vicat apparatus per IS 4031 (Part 5):1988. The initial setting time must be at least 30 minutes, and the final setting time must not exceed 600 minutes.
Super sulphated cement is recommended for use in marine constructions, mass concrete requiring sulphate resistance, reinforced concrete pipes in groundwater, structures in sulphate-rich soils, chemical plants exposed to sulphates and mild mineral acids, bridge undersides over railways, and sewers handling industrial waste. It is suitable for tropical climates with temperatures below 40°C. Limitations include avoidance in steam-cured products and adherence to agreed chloride content limits. The cement must contain at least 70% finely ground granulated blast furnace slag for optimal performance.
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