Use of Industrial By-Products in Concrete Production Achieve Lower CO2 emission

Lopamudra Sengupta, Sr. Vice President (Technical services)
Dr. L.R.Manjunatha, Vice President - Direct Sales & Sustainability Initiatives
Abhishek Awasthi & Abhijeet Landage, Concrete Technologist, JSW Cement

As every one ton of Cement (OPC) produced, emits 0.96 tons of CO2, there is an urgent need to promote blending materials (ex. GGBS &PSC) and screened slag, to achieve lower CO2 emissions, reduce greenhouse gas effect, reduce exploitation of natural resources, use alternate industrial byproducts in the production of concrete, and encourage alternate fuel usage, etc.

The need of the hour is “greener or lesser polluting cements or cementitious products” by use of industrial byproducts such as Ground Granulated Blast Furnace Slag, which is otherwise a waste, if not consumed.

Slag is a non-metallic and non-hazardous byproduct of the Steel industry, having cementitious properties. The cement industry utilizes slag in cement manufacturing and ground granulated blast furnace slag in concrete production.

The Portland slag cement & GGBFS thus produced imparts many properties to concrete and other applications where cement is being used. Screened slag from the house of JSW Cement is an excellent replacement of natural or manufactured / crushed sand (replacement level is fully or partly depending on design requirement). The screened slag conforms to IS 383 and grants excellent strength and durability in concrete/mortar works, along with conservation of natural resources.

PSC/GGBS as an Eco-Friendly product

• JSW provides products that are Sustainable & Environmental Friendly
• Pollution (air, water & land) free environment ensures no adverse impacts on the health of nearby communities
• Utilization of slag and other by-products minimizes burden on landfills
• Reduced virgin material usage
• Reduced fossil fuel usage
• Creates sustainable sites using PSC /GGBS concrete
• Builds concrete with low embodied energy using PSC/GGBS
• Use concrete that contains recycled materials
• By use of PSC & Ground Granulated Blast Furnace Slag, Low carbon concrete can be produced, reducing carbon dioxide emission and at the same time quality of concrete is improved.

Advantages of JSW green products for end-consumers

• Long term strength of concrete made with JSW green products is greater than concrete made with OPC and PPC cement
• The concrete provides protection against corrosion of steel reinforcement
• Concrete made with JSW green products is almost impermeable
• Concrete cover remains intact
• Concrete provides resistance to sea water attack in marine environment
• Concrete offers better resistance to sulphate, chloride, harmful gases attack and ingress of atmospheric water
• Ensures long design life/durability of structure with low maintenance cost
• Cracks are minimized and reduced in structures.

The following products are available from JSW Cement

1. JSW Portland Slag Cement (JSW PSC)
2. JSW OPC
3. JSW Concreel HD
4. JSW Ground Granulated Blast Furnace Slag ( JSW GGBS)
5. Granulated Blast Furnace Slag Sand (GBS Sand)

Portland Slag Cement (PSC) & its Application
JSW PSC is a blended cement wherein some portion of OPC is replaced with GGBFS to make the structures long lasting and durable. GGBFS present in PSC helps in secondary hydration, producing more C-S-H gel in system for improved performance of concrete.

Some of the major advantages of JSW PSC are:

• Reduced thermal cracks due to lower heat of hydration as compared to OPC
• Reduced shrinkage cracks as compared to OPC, PPC
• Improved workability and smooth finish
• Improved cohesion
• Better resistance against chemicals such as chlorides, sulphates and carbon dioxide
• Higher long-term strength
• Improved durability
• Green product

JSW PSC can be used in all types of civil engineering works – both structural and non structural applications. In fact, it has got a wide spectrum of applications compared to OPC, which is not suitable for works such as mass concrete, industrial structures, marine structures, effluent and sewage treatment plants. On the other hand, PSC is ideal for these works, which makes it an all-purpose cement.

JSW PSC is a sustainable material. Since the production of PSC ensures the conservation of natural resource (limestone), savings in energy during production, and limiting the emission of carbon dioxide, it is regarded as eco-friendly.The properties of PSC have been specified by BIS in, IS: 455-2015, and CII – IGBC have certified, JSW PSC as a green product. Concreel HD & its Application
JSW Concreel HD is a cement with a high initial strength, high final strength, quick setting, superior cohesion, most durable, chemical resistant, and is a green product that conforms to IS: 455 – 2015. It is an ideal product for all kinds of concreting works and can be used right from foundation to plastering.

GGBS & its Application
Slag is a by-product of steel plants. It is obtained from the blast furnace during the separation of iron from the iron ore. The process of granulating of the slag involves cooling of molten slag through high-pressure water jets, which rapidly quenches the slag and forms granular particles. The resulting granular material comprises around 95% non-crystalline calcium-alumino silicates. The granulated slag is further processed by drying and then grinding in a vertical roller mill or rotating ball mill to a very fine powder, which is called GGBS.

The benefits, application and performance of GGBS are same as that of PSC. In case of PSC, predetermined dosage of GGBS is added, whereas GGBS (separately combined with OPC) offers flexibility of using any particular dosage, depending on the choice of the user.


Some of the major advantages of JSW GGBS concrete, as compared to pure OPC concrete or flyash-based concrete are given below:

• Reduced thermal cracks due to lower heat of hydration
• Reduced shrinkage cracks
• Improved workability and smooth finish
• Improved cohesion
• Better resistance against chemicals such as chlorides, sulphates and carbon dioxide
• Higher long-term strength
• Improved durability
• JSW GGBS meets the requirements of IS:12089-1989 and is an eco-friendly product
• It can be used as partial replacement for OPC cement in concrete production at RMC batching plants and site batching plants

Granulated Blast Furnace Slag Sand (GBS sand) & its Applications
Fine aggregates are an integral part of mortar, concrete, and plaster. River sand is regarded as an ideal fine aggregate. However, in recent years, due to non-availability of good quality river sand, crushed rock fines (CRF), are being used as fine aggregates. But CRF has some limitations, such as lack of moisture retention, making the mix non-cohesive/harsh and has a higher water demand.

GBS sand is an alternate to river sand as well as CRF. Slag obtained from blast furnace of steel plant is in the form of granules and looks like river sand, but is little greyish in colour. It is an inert material and is suitable for concrete and mortar, and can replace natural sand or CRF, up to a certain percentage (subject to field trials). The method of application of GBS sand is same as that of river sand / CRF. GBS sand had been tested, both in India and internationally, and found to be suitable to be used in mortar and concrete.


GBS sand is superior to river sand because the latter contains fossils and other irregular particles like clay and silt that affects quality and durability. Also, dredging of river sand is not eco-friendly.

Use of GBS helps in maintaining harmony with the ecology as there is no quarrying, depletion of natural resource, and there is energy saving in crushing of the rocks. Like other products of JSW Cement, it is eco-friendly and JSW Slag sand meets all the requirements of IS:383-2015. GBS sand can be used as replacement of natural sand or CRF in concrete and mortar.