Fly Ash
Supplementary cementitious material for concrete and infrastructure
Supply Origins
Packaging
Jumbo Bags (1MT)
Related Products
About Fly Ash
Fly Ash (Class F) is a fine pozzolanic powder collected from flue gases of thermal power plants burning pulverised bituminous or sub-bituminous coal. Conforming to IS 3812 (Part 1): 2003 and ASTM C618, Class F fly ash reacts with calcium hydroxide released during Portland cement hydration to form additional C-S-H gel, improving long-term compressive strength, reducing permeability, and enhancing resistance to sulphate attack and alkali-silica reaction (ASR). Its use as a 20–35% cement replacement significantly lowers the carbon footprint of concrete construction. First Chemicals supplies fly ash sourced directly from Indian thermal power stations with consistent quality and full documentation.
Key Applications
- Ready-mix and precast concrete (20–35% cement replacement)
- Portland Pozzolana Cement (PPC) and Portland Slag Cement (PSC) manufacturing
- Road sub-base and embankment fill
- Mass concrete structures (dams, raft foundations)
- Geotechnical applications — mine backfill and reclamation
- AAC blocks and lightweight concrete panels
Typical Specifications
* Specifications are typical values. Actual COA provided with each shipment.
Frequently Asked Questions
What is Class F fly ash and how is it different from Class C?
Class F fly ash is produced from burning bituminous or sub-bituminous coal and has a combined SiO₂ + Al₂O₃ + Fe₂O₃ content of ≥70% with CaO below 10%. It is pozzolanic (requires Ca(OH)₂ to develop strength). Class C fly ash, from lignite coal, has higher CaO (≥10%) and is self-cementitious. First Chemicals supplies Class F fly ash conforming to IS 3812 (Part 1): 2003.
What percentage of cement can be replaced with fly ash in concrete?
Typically 20–35% by weight of cementitious material in standard structural concrete. For mass concrete (dams, raft foundations) up to 50% replacement is used to reduce heat of hydration. The exact replacement level depends on grade of concrete, exposure conditions, and IS 456 / project specifications.
What are the benefits of using fly ash in concrete?
Fly ash improves long-term strength, reduces water demand (improves workability), lowers heat of hydration, enhances resistance to sulphate attack and ASR, reduces permeability, and cuts the carbon footprint of concrete by replacing clinker. It also reduces cost vs. ordinary Portland cement.
Does First Chemicals supply fly ash with a COA?
Yes. Each consignment comes with a Certificate of Analysis (COA) covering SiO₂+Al₂O₃+Fe₂O₃, CaO, LOI, fineness, and moisture, tested against IS 3812 (Part 1): 2003 limits.
What is the packaging and minimum order for fly ash?
We supply fly ash in 1MT jumbo bags (FIBC). Minimum orders are typically one full truck load (20–25 MT). For larger project requirements, bulk powder tanker supply can be arranged. Contact us for project-specific pricing.