The unprecedented infrastructure growth in the country needs to be sustainable. Speaking to Buildotech, Pankaj Kulkarni, Director, JSW Cement elaborates on the company’s route of utilizing industrial by-products to make eco-friendly cement.
JSW Cement’s focus on eco-friendly products was a conscious decision as the company intends to play a leading role in the sustainable construction material sector in the coming years. The company also enjoys a competitive edge over other cement manufacturers, since JSW has its own blending material viz Slag and Fly ash.
We are manufacturing two products namely – Ground Granulated Blast Furnace Slag cement (GGBS) and Portland Slag Cement (PSC). Our current production capacity is 6.0million ton and we produce 4.0million ton of both. JSW Cement uses slag – a by-product from the Group’s steel units – which would otherwise have contributed to environmental pollution and converts it into ‘green cement’.
Ground Granulated Blast Furnace Slag (GGBS) – JSW Cement is the largest producer of GGBS in the country and pioneered its use in Western and Southern India. Obtained during the steel making process, the slag is quenched to form sand like granules which when crushed displays cementitious properties and can replace clinker in cement. The chemical composition of GGBS contributes to the production of a superior cement with lower permeability and higher corrosion & sulphide resistance. Moreover, over the period of time, its load-bearing properties continue to increase as it absorbs surplus lime released during hydration to form more calcium silicate hydrates. These hydrates add to the strength of the cement.
This increased strength makes suitable for the construction of high-rise buildings, marine applications such as dams, shore protection construction, effluent and sewage treatment plants, and cement products such as tiles, pipes, blocks, etc.
Portland Slag Cement (PSC) – It is created with a combination of 50% slag, 45% clinker and 5% gypsum. Apart from being more environmentfriendly, it offers several advantages over Ordinary Portland Cement (OPC) – higher strength over a period of time, greater life span of construction and better workability. It has higher resistance to chemicals such as sulphates and chlorides, lower heat of hydration and higher proportion of calcium silicate hydrates that increase the strength.
There are two main advantages of these products – firstly as they reduce cement content by up to 50%, carbon emissions are reduced to the tune of 1.0- 1.25 ton of CO2 for every one ton of cement produced. Secondly, lime stone is used in conventional cement production. By industry estimates, in India we have lime stone reserves for next 30 years only. So using, by products, the use of lime resources is also minimized.
Developed counties are already using these cement products and with green standards getting more stringent in India, GGBS and PSC are the materials of the future. We adhere to BIS standards of manufacturing these products and have even surpassed these standards. Reliance Convention Centre, High rise buildings of Lodha builders and Metro schemes are some of the projects that have used PSC or mixed GGBS with OPC to make concrete for construction.
Misconceptions & Awareness
The two major misconceptions about slag based cement are its lighter colour and delayed initial setting. There is a fallacy among consumers that darker the colour, stronger will be the cement, which is not true. In fact lighter colour means the cement will absorb less sunlight reducing heat load, expansion & contraction will be less and aesthetically too it is more pleasing.
Similarly, the concrete strength measured on 28 basis is same for both OPC and GGBS concrete. The initial strength development for GGBS concrete is lower but ultimate strength is same as regular concrete. In fact, after 28 days, rate of development of strength of regular concrete starts going down, while GGBS concrete continues to gain strength thereby increasing life of the structure. Also, the heat of hydration is lower in slag-based cement, thus leading to fewer cracks from thermal stress.
To address these concerns and educate the market about the products usage and application, we have special technical services and educational teams that engage with the masons, engineers, builders, owners and government officials. We also talk to civil engineering students to create awareness at education level itself about the ecofriendly cement material options.
Most of the steel companies in India are based in the eastern states and thus the cement companies there have a regular supply of slag. Not surprisingly, consumers in this region are well aware of PSC and GGBS cement. In fact, slag cement forms 35-40% of the consumption by consumers here. JSW initiated operations in 1999 by putting up a steel plant in south of India. In 2009 we started with a small grinding unit of 6-7Lakh ton at Vijayanagar, Karnataka. Thus, the company introduced slag cement to the region which was well accepted in Bangalore and adjoining areas. Presently, the entire slag cement production is consumed within 250km radius. To keep up with the demand, in 2012, the first clinkerization facility was commissioned along with additional grinding units in Nandyal in Andhra Pradesh & Dolvi in Maharashtra.
JSW Cement is sold in Telangana, Andhra Pradesh, Karnataka, Tamil Nadu, Kerala, Maharastra, Orissa and Goa. We sell PSC directly in the market to consumer for building, homes or foundations construction etc. GGBS is sold as product to Ready Mix Concrete (RMC) manufacturers for mixing with OPC in concrete. Using slag-based cement in concrete offers a number of advantages including increased strength, less corrosion, heat and waterresistance and longevity. All major RMC companies in Bangalore and Mumbai are using our product.
JSW Cement had also been producing and marketing OPC, which was discontinued in April 2014 and the company is now only selling only PSC and GGBS. This is in line with the company core value of sustainability. Even the Green colour bags for cement denote the eco-friendly nature of the material.
With the rising awareness in Southern region, we have reached 3-4% of the PSC market share in just two years. In western region, we have a small capacity which is running at maximum to fulfil the demand. With our continuous focus on these two products, we expect sharp growth in Company market share in the near future.