Blogs & articles

Concrete is a mixture of cement, coarse and fine aggregates and water. It plays a crucial role in building infrastructure. The cost of concrete is accredited to these ingredients, which are not only expensive but also scarce. Concrete manufacturing emits a considerable amount of Carbon dioxide (CO2). The pursuit of an alternate material which is economical and sustainable ended with the discovery of Ground Granulated Blast-furnace Slag (GGBS).

GGBS is a non-metallic product obtained as a by-product from the blast furnaces used to make iron. It consists of silicates and aluminates of bases such as calcium. Blast furnace varies in physical structure and composition depending on the cooling method of the slag. It is obtained by the rapid chilling of the molten ash with the help of water. The slag is transformed into the glass during this process and eventually refined to the required fineness.

For the uninformed, GGBS is identifiable by its colour. Conventional portland cement is grey, while the GGBS is white in colour.

There are two methods of using GGBS in concrete. You can integrand the GGBS with the cement clinker and gypsum or mix the blast furnace with cement separately. Apart from that, GGBS can also be used as the direct replacement of ordinary portland cement; the replacement may vary between 30-80% of cement. In India, generally, GGBS is used by adding it to batching plants along with the portland cement, water and aggregates.

Uses of GGBS: -

1. Producing Portland Blast furnace cement (PBFC) and High Slag Blast furnace cement (HSBFC).

2. Producing ready mixed concrete 

3. Used in ready mix concrete plants

4. Used in constructing structures which are vulnerable to chloride and sulfate attacks (for, e.g. marine and substructures) 

Advantages of GGBS

GGBS concrete has better ultimate strength and a higher proportion of the strength-enhancing calcium silicate hydrates than portland cement concrete. It also contains a lesser amount of free lime. The other advantages of GGBS include: -

1. Due to reactive silica in GGBS, replacing cement with GGBS in concrete mixes enhances the structural performance in terms of strength and durability.

2. The reactivity of GGBS with cement offers an increase in the compressive strength for different concrete mixes made with partial replacement of cement by GGBS

3. Reduction in the energy consumption in cement manufacturing

4. One tonne of portland cement manufacturing requires around 1.5 tons of mineral extraction along with 5000 MJ of energy and would generate around 0.95 tons of CO2 equivalent. In contrast, GGBS’s global warming potential is at 60.21 kg CO2 equivalent, among the lowest in the industry.

5. Use of GGBS in concrete generates less heat than cement. It also helps reduce the hydration heat, reducing shrinkage and temperature cracks.

6. Lesser void, hence decreased permeability in concrete.

7. Increased resistance to sulphate attacks.

GGBS Applications

GGBS in combination with portland cement) is used to make long-lasting structures such as: -

1. Concrete roads and flyovers

2. Dams

3. Residential houses

4. Commercial towers

5. Marine works

6. Foundation constructions

7. Effluent treatment plants

Reduction in CO2 emissions through a cost-effective alternative has been a challenge for the construction industry for the longest time. GGBS is one of the eco-friendliest construction materials in the modern construction industry. The manufacturing of GGBS utilises all the slag, incurring zero environmental waste. 

For homeowners looking to build healthy homes while creating minimal environmental impact, the popularity of GGBS should be no wonder. It enables you to construct a sustainable home and saves you a lot of money.

JSW Cement GGBS’s inherent chemistry gives it several advantages over ordinary portland cement, like higher flexural strength, improved cohesion, smoother finish, lesser susceptibility to chemical attacks and enhanced workability.

If you are somebody who is planning to construct a home, consider switching to GGBS today!