The standard delineates specifications for inorganic aggregates like perlite, natural and manufactured sand, and vermiculite utilized in gypsum plaster production. It sets forth criteria to assure the aggregates' quality and appropriateness, covering physical characteristics, impurity limits, and sampling protocols. This guideline is vital for professionals engaged in manufacturing and quality assurance of gypsum plaster materials.
Overview
The standard delineates specifications for inorganic aggregates like perlite, natural and manufactured sand, and vermiculite utilized in gypsum plaster production. It sets forth criteria to assure the aggregates' quality and appropriateness, covering physical characteristics, impurity limits, and sampling protocols. This guideline is vital for professionals engaged in manufacturing and quality assurance of gypsum plaster materials.
Audience
Contents
Structure
This section outlines the scope of the standard, covering lightweight aggregates such as perlite, vermiculite, and sand used in gypsum plaster. It includes essential grading requirements with detailed sieve size retention limits to guarantee appropriate particle size distribution for optimal performance.
Defines key terms related to lightweight aggregates including perlite, vermiculite, and sand. It also describes grading criteria based on sieve analysis specifying minimum and maximum retention percentages for each aggregate type to maintain uniformity and quality control.
Specifies limits for particle size distribution determined through sieve analysis for perlite, vermiculite, and sand. It also discusses rounding procedures for test results and criteria for material acceptance or rejection based on mass and volume measurements.
Details the physical property requirements including sieve analysis procedures, sample volumes, sieving durations, and volume measurement techniques. Emphasizes volume-based grading crucial for lightweight aggregates to ensure conformity with standards.
Covers allowable limits for water-soluble impurities and sodium ion content in sand. Describes testing methods including boiling, filtering, evaporating, and weighing residue to quantify impurities ensuring sand suitability for gypsum plaster.
Explains sampling protocols for bagged aggregates, including minimum sample sizes, use of sampling tubes, and combining samples to form a representative gross sample. Describes sample size reduction techniques like quartering or riffling for testing purposes.
Outlines test methods such as sieve analysis with specified grading limits and sample preparation. Includes rejection criteria for packages based on mass and volume deviations and reference to related IS methods for additional tests.
Details requirements for marking packages with manufacturer details, aggregate type, minimum mass, and approximate volume. Specifies rejection conditions for individual packages and shipments based on deviations in mass and volume.
Summarizes inspection protocols and criteria for rejecting materials and shipments. Includes sampling frequency, evaluation of mass and volume against specified limits, and ensuring compliance with grading and labeling standards.
Frequently Asked
The standard encompasses inorganic aggregates commonly used in gypsum plaster manufacturing, specifically perlite, natural and manufactured sand, and vermiculite. Other inorganic aggregates may be used provided they are tested and confirmed to yield gypsum plaster of acceptable quality. The focus is on lightweight, chemically stable aggregates to ensure proper plaster performance.
As per the standard, sand utilized in gypsum plaster should have water-soluble impurities not exceeding 0.15% by mass. Additionally, the sodium ion concentration must be limited to a maximum of 0.02% by mass. Sand must also pass a colorimetric test for organic impurities, producing a color no darker than the specified reference, unless demonstrated to be non-detrimental.
The standard specifies that perlite aggregates should have a bulk density ranging from 100 to 200 kg/m³, whereas vermiculite aggregates must fall between 100 and 160 kg/m³. Measurement involves collecting a representative sample, determining its volume—typically with a container of known dimensions—and weighing the sample. Bulk density is then calculated by dividing the mass by the measured volume, ensuring the aggregate meets specified density criteria.
Sampling protocols include selecting at least one bag per 100 bags, with a minimum of six bags per shipment for large consignments. For smaller shipments, six percent of the bags should be sampled. A sampling tube is inserted diagonally through horizontally laid bags to obtain representative portions. These portions are combined to form a gross sample of at least 28 dm³. The sample is then reduced using quartering or riffling methods to the required test size, ensuring representativeness and compliance with testing standards.
Shipments can be rejected if individual package mass is less than 95% of the declared weight or package volume is below 90% of the indicated volume. Additionally, if the average mass of two randomly sampled packages per 100 (minimum six packages) is below the declared mass, or if the average volume deviates beyond +5% or -10% of the declared volume, the entire shipment may be rejected. Compliance with grading and proper labeling is also mandatory for acceptance.
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