Product Details

Ground Granulated Blast Furnace Slag

GGBS slag is by product of iron and steel manufacturing process. It contains the entire basic constituent of OPC but not exactly in the same ratio and chemical form. Slag itself has no cementing property but when mixed with OPC, it develops hydraulic properties similar to cement. The calcium oxide (CaO) found in slag is tied up as calcium silicate, calcium aluminates and calcium alumino silicates. Although these compounds are not identical to those found in Portland cement (i.e. tricalcium silicate, tricalcium aluminates etc), they hydrate when activated by calcium hydroxide generated during the hydration of Portland cement. Since GGBS is almost 100% glassy, it is generally more reactive. This process of quenching is called granulation because it produces glassy granules similar in appearance to coarse sand, having excellent cementitious property when ground to high fineness and mixed with cement.

Replacement of OPC with GGBS increases the durability and workability without affecting strength. Thus finally it is cost effective solution in current competitive market.

Granulated slag obtained from blast furnace slag is wet and coarse in nature and can not be useful directly. So drying and grinding process are carried out to make it useful.

Normally ball mill is used to make it fine in nature. There is no any chemically changes happens during this process only physical nature of the material is being changed from coarse to fine.

During grinding process classification is also carried out simultaneously in order to maintain uniform particle size.

GGBS replaces a substantial proportion of normal cement OPC in RMC. The mixing varies from 30% to 70% approximately (generally 50%). The higher the proportion, the better is durability for concrete. GGBS is also used in other forms of concrete including site batched and precast.

Superior Quality Concrete

Improved workability, pumpability and compaction characteristics
for concrete placement Increased strength
Reduced permeability
More chemically stable
High resistance to chloride penetration
Very low heat of hydration
Improved resistance to attack from fire

Superior Appearance

Improved surface finish
Lighter and more even color
Enhanced reflectivity for greater visibility and safety
Suppresses/eliminates efflorescence

Low Environmental Impact

Use of GGBS extends the life cycle of concrete structures
Enhanced durability, reduced maintenance and repair costs
Reduces construction costs
Low carbon footprint

Better Value for Money

Enhanced durability and strength longer life
Enhanced architectural appearance reduced need for other expensive finishes or painting
Lower maintenance costs
Enhanced life cycle
No additional premium on material costs

GGBS is a fine powder, used in concrete as "cement", major use in ready mixed concrete (RMC) or in the production of Portland slag cement. GGBS replaces a substantial proportion of normal cement (Ordinary Portland Cement) in RMC. The mixing varies from 30% to 70% approximately (generally 50%). The higher the proportion, the better is durability for concrete. GGBS is also in other forms of concrete including site-batched and pre-cast.

Replacement of Portland Cement by adding up to 70% GGBS, reduce cement content in concrete from about 530 Kg/m3 to 160 Kg/m3 and despite of this large reduction of cement in concrete, ultimate strength is not affected, also considerable improvement in durability properties is observed.

GGBS is used as green construction material.

High rise building construction
Marine applications such as Dam, Shore protection construction.
Effluent treatment plant
Sewage system construction
Cement products like Pipe, Tiles, Blocks etc.
Substantially replacement of cement.

Physical properties as per BS 6699:1992

Characteristics	Specification	Typical
Moisture (%)	10 max	0.38
Fineness
Specific Surface area (m2/kg)	275 min	395
Retention on 45 micron (%)	No limit	2.90
Setting time
Initial minutes	60 min	195
Final minute	No limit	290
Soundness
Le-Chatelier Expansion (mm)	10 max	1.0
Compressive strength
(Mortar) with Portland cement (PC)
2 days-N/mm27 days-N/mm2	10.0 min	28.3
7 days-N/mm2	No limit	38.2
28 days-N/mm2	42.5-62.5	47.40
(Mortar) with 70% GGBS +30% PC
2 days-N/mm2	No limit	10.40
7 days-N/mm2	12.0 min	24.10
28 days-N/mm2*	32.5 min	42.10
Glass content (%)	67 min	94.00

Chemical composition as per BS 6699:1992

Composition (%)	Specification	Typical value
Loss on Ignition (LOI)	3.0 max	0.65
Insoluble Residue (IR)	1.5 max	0.42
Silica as SiO2	No limit	34.52
Alumina (Al2O3)	No limit	13.95
Iron oxide (Fe2O3)	No limit	0.90
Calcium oxide (CaO)	No limit	41.75
Magnesium oxide (MgO)	14.0 max	6.03
Sulphur trioxide (SO3)	2.5 max	0.26
Sulphide Sulphur	2.0 max	0.70
Sodium oxide (Na2O)	No limit	0.30
Potassium oxide (K2O)	No limit	0.34
Chloride (Cl)	0.10 max	0.01
Manganese oxide (Mn2O3)	2.0 max	0.45

Chemical ratio
CaO+MgO+SiO2	66.67 min	82.30
(CaO+MgO)/SiO2	1.0 min	1.38
CaO/SiO2	1.4 max	1.21

Enhanced Performance in Construction

GGBFS is utilized to boost the strength and durability of concrete structures. Its finely ground nature blends smoothly with cement, aiding in longer-lasting, chemical-resistant constructions. The materials low thermal conductivity and dimensional stability make it suitable for demanding engineering applications.

Safe and Sustainable Supplement

With low toxicity, negligible chloride or alkali content, and high purity, GGBFS is safe for workers and the environment. Sourced from blast furnace slag, it supports sustainable development by recycling industrial byproducts into value-added construction materials.

Versatile Applications and Easy Storage

GGBFS is applied as a cement replacement, admixture, or road base stabilizer. Available in bulk or jumbo bag packaging, it can be easily stored in moisture-proof silos or containers to preserve its fine powder quality. Its stable characteristics ensure consistent performance in concrete mixes.

FAQs of Ground Granulated Blast Furnace Slag:

Q: How is Ground Granulated Blast Furnace Slag used in concrete and construction projects?

A: GGBFS is primarily blended with ordinary Portland cement to serve as a supplementary cementitious material, improving concretes compressive strength, durability, and chemical resistance. It is also used in road construction, soil stabilization, and as an aggregate in refractory concretes.

Q: What are the main benefits of using GGBFS as a cement replacement?

A: Using GGBFS enhances concretes long-term strength, reduces permeability, and increases resistance to chemical attack. Additionally, it typically extends the initial setting time, which can be advantageous for large pours or hot-weather concreting, and supports sustainability by recycling an industrial byproduct.

Q: When should GGBFS be added during the concrete production process?

A: GGBFS is generally mixed with the cement and other components during batching, prior to adding water. This ensures thorough dispersion throughout the concrete mixture, promoting uniform performance and optimal strength development.

Q: Where should Ground Granulated Blast Furnace Slag be stored to maintain its quality?

A: To retain its fine powder consistency and prevent moisture absorption, GGBFS should be kept in dry, moisture-proof silos or sealed containers, whether in bulk or in jumbo bags.

Q: What is the chemical composition and physical nature of GGBFS?

A: GGBFS primarily contains 35-42% CaO, 32-38% SiO2, 7-16% Al2O3, and 4-12% MgO, with a specific gravity of 2.9-3.0 and a fine powder or granular form. Its color ranges from light grey to off-white, and it exhibits low porosity, low water absorption, and high purity.

Q: Is GGBFS compatible with other concrete admixtures and Portland cement?

A: Yes, GGBFS is fully compatible with ordinary Portland cement and most modern concrete admixtures, facilitating versatile formulation options for different project requirements.

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