Everything can make or break when constructing a home or any other structure due to the quality of cement. In India, the Bureau of Indian Standards (BIS) is the organisation that makes sure that each bag of cement that you purchase has a high standard of quality. Among the major standards established by BIS is the IS 1489 (Part 2), which is related to Portland Pozzolana Cement (PPC) manufactured by means of the use of calcined clay-based pozzolanic materials. Assuming you are a builder, engineer or a homeowner, then here is all you need to know about this standard in simple terms.
What Is Portland Pozzolana Cement?
Pozzolana Cement Portland Pozzolana Cement or Portland Pozzolana Cement is a form of blended cement. It is prepared by combining Ordinary Portland Cement (OPC) clinker, pozzolanic materials and gypsum. Pozzolanic materials are special substances which are reactive with water and calcium hydroxide to form strong binding compounds, just like cement. The IS 1489 standard is divided into two sections depending on the material of pozzolana employed. Part 1 involves the use of fly ash, and Part 2 involves the use of calcined clay or other pozzolanic materials like volcanic ash and burnt shale.
What Is Calcined Clay?
Calcined clay is merely ordinary clay that has been burnt at high temperatures – normally between 600 deg C and 900 deg C. This heating is what makes the clay active and extremely reactive, such that it can bond with cement particles. The outcome is a stronger, more durable and resistant cement to environmental destruction. The same is the case with volcanic ash and other naturally-derived materials that fall under Part 2. These materials can be found locally in most regions in India, which makes them a viable and sustainable material in the production of cement.
Understanding IS 1489 (Part 2)
The IS 1489 (Part 2) is the official Indian Standard specifications published by BIS on Portland Pozzolana Cement, which is produced with the help of the use of calcined clay-based pozzolanic substances. This standard outlines all the quality provisions that a manufacturer is supposed to fulfil before the sale of this cement in India. And simply put, it is the quality rulebook. When a cement bag bears the BIS ISI mark under this standard, it indicates that the item has been tested and certified as to its quality and safety on its own.
Key Requirements of IS 1489 (Part 2)
This category of cement has clear technical standards established by the standard. The content of pozzolanic material should be between 15 and 35 per cent of the total mass of the cement, at once a proportionate range that provides both laborability and durability of the strength. The cement should contain a minimum fineness (specific surface area) of 300 m 2/kg that guarantees high reactivity between the cement and pozzolanic particles.
When starting the first setting should not start earlier than 30 minutes, allowing the workers additional time to work with the concrete. The last setting is required to be done in 600 minutes (10 hours). In compressive strength, the cement will have to reach 16 Mpa at day three, 22 Mpa at day seven, and 33 Mpa at day 28- values which indicate that the cement is sure to work on safe and stable structures. The soundness test (Le Chatelier method) should not indicate any more than 10mm expansion, due to which the cement might not crack or expand once hardened. The standard also restricts the contents of magnesium oxide, sulphur trioxide and other chemical substances to ensure long stability.
The BIS Certification is Important
BIS certification is not a mere name but rather an assurance of quality, which has the Government of India endorsement. Here is why it is so important. First, it protects consumers. By purchasing cement that is BIS-certified, you are not putting your trust in the manufacturer; you are placing it in a system of independent testing and verification. Second, it promotes the safety of the structure. Poor cement may result in poor concreteness, cracks and a collapse of the building. Certified cement would assure you that you have years of stability for your structure. Third, BIS certification leads to compliance with the law. Government construction projects and most of the projects under building codes in India require certified cement to be used. Lastly, the application of PPC under the IS 1489 (Part 2) is environmentally friendly. When manufacturers substitute a percentage of OPC clinker with calcined clay, they reduce energy consumption and carbon dioxide (CO2) emissions; therefore, it is a more sustainable choice for construction.
Where Is This Cement Used?
PPC, certified to IS 1489 (Part 2), is used in most construction works, such as residential buildings, bridges, dams, foundations, marine structures, underground tunnels, and plastering. It has a low heat of hydration, so it is particularly suitable in large concrete pours, such as dams and massive bases, where excessive heat may lead to damaging thermal cracking.
Final Thoughts
The combination of IS 1489 (Part 2) and BIS certification also guarantees that Portland Pozzolana Cement produced using calcined clay is of the best quality and safety in India. Buy cement to construct a small home, or a massive infrastructure, never fail to see the ISI mark on the bag. You will guarantee that the cement is tested, certified and acceptable by the Bureau of Indian Standards, which is the most reliable in quality certification in India.
Build confidently. Build safely. Construct using cement that is certified by BIS.
