The 2003 edition of IS 2645 outlines the criteria and testing protocols for integral waterproofing admixtures used in cement mortars and concrete. It guarantees that these additives effectively minimize water penetration without compromising critical properties such as setting time and compressive strength. This specification is intended for manufacturers, engineers, and quality assurance personnel involved in incorporating waterproofing agents to improve the longevity and moisture resistance of cementitious mixes.
Overview
The 2003 edition of IS 2645 outlines the criteria and testing protocols for integral waterproofing admixtures used in cement mortars and concrete. It guarantees that these additives effectively minimize water penetration without compromising critical properties such as setting time and compressive strength. This specification is intended for manufacturers, engineers, and quality assurance personnel involved in incorporating waterproofing agents to improve the longevity and moisture resistance of cementitious mixes.
Audience
Contents
Structure
IS 2645 defines the specifications and evaluation methods for integral waterproofing compounds incorporated into cement mortars. The standard applies to waterproofing additives used to reduce water penetration in cementitious mixes. It includes guidelines on sampling, testing, and certification. The permeability test involves assessing water flow through mortar specimens with and without the waterproofing agent. Sampling quantities depend on lot size as per specified tables. Referenced Indian Standards such as IS 269, IS 455, IS 650, IS 4031 parts 5 & 6, IS 8112, and IS 12269 provide additional context on cement types and test methodologies. Test specimens are cured under controlled conditions, and final values are rounded following IS 2:1960 rules.
Annex A lists key Indian Standards referred to in IS 2645, covering cement specifications, standard sand for testing, and test methods for physical properties and chemical analysis. These include IS 269 (OPC 33 Grade), IS 455 (Portland Slag Cement), IS 650 (Standard Sand), IS 1489 Parts 1 & 2 (Portland Pozzolana Cement), IS 1727 (Pozzolanic materials testing), IS 4031 Parts 5 & 6 (Physical tests for cement), IS 6925 (Water soluble chlorides testing), IS 8112 (OPC 43 Grade), and IS 12269 (OPC 53 Grade). Final test results must be rounded as per IS 2:1960. The permeability test procedure requires preparing mortar specimens with specified water flow characteristics, compacted in layers using a 500 g rammer, cured at controlled temperature and humidity, and subjected to incremental water pressures.
The standard mandates rounding of numerical results following IS 2:1960 to maintain consistency in significant figures. Updated clauses specify limits on compressive strength and setting times for mortar containing waterproofing compounds. Standard sand used for testing must conform to IS 650 with a specified gradation ensuring consistency in mortar preparation. The sand grading includes cumulative retained percentages at various sieve sizes to guarantee uniform particle size distribution. Detailed clauses provide exact numerical values for strength and setting time requirements.
Sampling ensures representative testing by selecting a prescribed number of containers or bags from a lot based on size. Samples from selected containers are combined to create a composite sample for analysis. The sampling plan specifies quantities from lots ranging from up to 25 to 500 containers, ensuring statistical reliability. This approach upholds uniformity and accuracy during quality evaluation of waterproofing compounds.
Mortar specimens of cylindrical shape (100 mm diameter by 50 mm height) are prepared and tested for water permeability using a specialized setup. The apparatus consists of a water cell made of brass, pressure vessels constructed from galvanized steel, and non-corroding plates and pipelines. Water pressure is applied incrementally via a compressor and regulator system. The permeability test measures the volume of water passing through the specimen, with acceptance criteria requiring that permeability with the waterproofing compound be no more than 50% of the control specimen without the additive. Test results are rounded per IS 2:1960.
Containers or bags containing the waterproofing compound must be clearly and permanently labeled with essential information including product name, manufacturer details, brand, manufacturing date, batch number, maximum chloride content, recommended dosage, usage instructions, safety precautions, storage conditions, and expiry date. Products may bear the BIS Standard Mark subject to licensing under the Bureau of Indian Standards Act, 1986. Sampling for packaging compliance follows the outlined sampling plan ensuring lot representation.
This annex enumerates Indian Standards referenced for cement and mortar testing such as IS 269, IS 455, IS 650, IS 1489 Parts 1 and 2, IS 1727, IS 4031 Parts 5 and 6, IS 6925, IS 8112, and IS 12269. These standards cover cement types, physical and chemical test methods, and mortar preparation protocols. The annex also briefly outlines the standard procedure for water permeability testing of cement mortar with and without waterproofing compounds.
Specimens measuring 100 mm in diameter and 50 mm in height are tested using a permeability apparatus comprising a brass water cell, galvanized steel pressure vessel, and non-corroding pipeline components. Water pressure is applied incrementally, and water passing through the specimen is collected and measured. The test ensures that the permeability coefficient of mortar containing the waterproofing compound does not exceed half that of the plain mortar. The calculation of permeability follows the formula k = (Q×L)/(A×H×t), where variables represent water volume, specimen thickness, area, hydraulic head, and time respectively.
The Cement and Concrete Sectional Committee (CED 2) responsible for IS 2645 includes experts from cement manufacturing companies, research institutes such as CBRI and CRRI, government bodies including CPWD, industry representatives from firms like Larsen & Toubro, academia from IITs and the Indian Institute of Science, and professional organizations like the Indian Concrete Institute. Leadership is provided by the chairman and secretary appointed for the committee. The annex includes tables summarizing sampling, mortar preparation, specimen compaction, curing, permeability testing pressures, and criteria for discarding faulty specimens.
Frequently Asked
IS 2645:2003 limits the chloride content in integral waterproofing compounds to a maximum of 2.0% by mass. Chloride levels must be determined according to IS 6925 and disclosed by the manufacturer. The dosage of the waterproofing agent should not exceed 3% by weight of cement to prevent corrosion risk. These restrictions ensure the durability and corrosion resistance of reinforced concrete elements using such compounds.
The standard prescribes preparing cylindrical mortar specimens both with and without the integral waterproofing compound. Using the specified proportions, specimens are cured under controlled conditions. Water percolation is then measured through these specimens employing an apparatus described in Annex B. The acceptance criterion mandates that permeability of mortar containing the waterproofing compound must be less than 50% of that measured for the control specimen without the additive.
According to IS 2645, the addition of integral waterproofing compounds (up to 3% by cement weight) may slightly alter setting times and compressive strength but within controlled limits. Initial setting time should not be reduced by more than 25%, and final setting time must not increase beyond 25% of the original cement values. Compressive strength at 3 and 7 days should be at least 90% of the strength of mortar without the waterproofing additive, ensuring minimal impact on performance.
IS 2645 permits the use of Ordinary Portland Cement grades 33, 43, and 53 (as per IS 269, IS 8112, and IS 12269 respectively) for testing waterproofing compounds. Additionally, with mutual agreement, Portland Slag Cement (IS 455) and Portland Pozzolana Cement types based on fly ash or calcined clay (IS 1489 Parts 1 and 2) may also be used. This ensures the waterproofing compounds are compatible with commonly used cement varieties in practice.
Integral waterproofing compounds must be packed in appropriate containers or bags to protect quality and prevent contamination. Each container should bear clear and permanent markings including product name, manufacturer details, brand name (if any), manufacturing date, batch number, maximum chloride content, recommended dosage, usage instructions, safety precautions, storage recommendations, and expiry date. The containers may also carry the BIS Standard Mark subject to licensing in accordance with the Bureau of Indian Standards Act, 1986.
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