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Clean, smart, quick

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Touted to be one of the fastest and greenest metro projects in India, Nagpur Metro recently witnessed the completion of the 11 km-long Reach 3 of the East-West corridor of Phase-1.

Nagpur is the 13th largest city by population in India. And according to an Oxford Economics report, it is projected to be the fifth fastest growing city in the world from 2019-2035, with an average growth of 8.41 per cent.

Evidently, the city needed a rapid and green transit network to help transform it into a smart city. This has been answered with Phase 1 of the Nagpur Metro project. Afcons Infrastructure recently completed the construction of Reach 3 of the East-West corridor of Phase 1 of the project in a record 28 months; the project will soon be inaugurated. The 11-km viaduct will soon provide better and safe transportation for the people of Nagpur.

Benefits to the city
A clean, smart and quick mode of transport is the need of the hour for the smart city of Nagpur. The metro-rail project aims at reducing traffic congestion; improving air quality and reducing pollution; significantly reducing travel time; and lowering the carbon footprint by shifting private vehicle users to energy-saving and efficient public transport. The metro-rail service between Sitabuldi and Lokmanaya Nagar stations provides connectivity to the educational hub in the city and MIDC Hingna, the industrial area.

Key highlights
Civil structure specifications in the construction of Reach 3 included: Foundation ? pile, pile cap, open foundation and pedestal; substructure – pier, cantilever pier cap, standard pier cap, portal; and superstructure – segment casting, segment launching, I-girder casting, I-girder erection deck slab casting.

Other highlights:
Nagpur Metro Phase 1 is a 41.7-km project, and Afcons’s scope includes 17.087 km in two stretches: Reach 2 (North-South corridor) and Reach 3 (East-West corridor), and, Sitabuldi Metro station (50 per cent of the entire phase)
370 spans launched in just 20 months with a record peak progress of 30 spans in one month.
3,456 segments cast in 20 months, a rare feat in the Indian metro-rail segment.
Sitabuldi Interchange Station made operational for the North-South and East-West corridors in just 20 months.

Execution records
Meticulous planning and efficient execution were the key factors that ensured that Nagpur Metro Reach 3 was executed in a record 28 months. As Vaikunth J Pai, Project Manager, Nagpur Metro Reach-3, Afcons Infrastructure, shares, "The team submitted the design and received the requisite approvals from the client on time. Afcons deployed three launching girders and six sets of ground support staging for segment launching. A considerable amount of time was saved when the number of portals in the project was reduced to 20 from 57." Further, another methodology used was segment casting-using the long-line method with 10 beds of segment casting.

Design and construction techniques
The Reach 3 corridor was planned in an efficient and sustainable manner. As Pai elaborates:
Segment launching over Govari Flyover using GSS and launching girders: At Nagpur Metro Reach 3 project, the Afcons team had to launch a segment on span over the busy Govari flyover at Jhansi Rani Square. However, the segment could not be hoisted in the conventional method as the existing structure was causing an obstruction. Therefore, a tower with single-piece sliders was erected near P293 at the end of the flyover. The segment was then placed on the tower using cranes and was lifted from there using an indigenously designed and fabricated launching girder.

– Maximum height of pier: 25 m
– Maximum curve radius: 125 m
– Maximum gradient: 2.461
– Maximum span length of viaduct: 36 m.

Afcons installed GSS sliders over cribs and launched the segment using the launching girder at the crossing of the nallah between the span in the Crazy Castle area.
A cantilever staging arrangement was used for the construction of pier arms at Ambazari Station. The station was constructed over the slope of a dam, where support was taken from the pedestal itself.

A GSS staging system was used for the construction of the pier arm to save time, as crib staging involves welding and cutting.
A combination of GSS and launching girder was used for launching at P169-170, which was obstructed by overhead and underground water tanks.
Construction of portal for future expansion: The Nagpur Metro project has been planned keeping in mind the possibility of expansion in future. The construction of a portal was proposed for this purpose. However, a challenge was that land was not available for the construction of one leg of the portal. Hence, Afcons designed the portal in such a way that it can be accommodated in available land, and expanded for future construction.

Construction of pier cap without pier arm at LAD station: The normal sequence of construction of the pier cap at the station location is to build the pier arm first and then the pier cap. As land was not available at the LAD station and waiting would have resulted in loss of time, pier caps were cast without casting the pier arm.
Fly ash was used as a replacement for cement in concrete.
At Ambazari, the team had to undertake activities around a dam. To maintain the stability of slope of the dam and avoid excavation in the area, the pile cap was constructed above the ground level. It made use of liner while piling to avoid the vibrations of winches at the dam location.
While making the segments, the team had to change the spacing of bars and increasing the diameter of steel while keeping the quantity of reinforcement same. Also, UPV test was done on each segment.

Quality materials
The project made use of high-quality materials in the construction of this stretch. As Pai shares:
Cement was blended with fly ash and GGBS for the mix design of concrete; this was not only cost-effective but improved the durability of structures.
Micro-silica as mineral admixture was used in concrete, which helped achieve high-grade concrete strength.
VMA (viscosity-modified admixture) was used in self-compacting concrete for controlled cohesiveness and homogeneity of the concrete mix.
A curing compound was used that benefitted the time cycle, resulting in acceptable compressive strength.
Highly fluid epoxy grout (EP-10, Make-Fosroc) and non-shrink grout GP-2 were used for repairing.
Polypropylene fibre was used in concrete for precast structures (segments), which prevented shrinkage of cracks and increased bonding strength.
Inhibitor solution was used to prevent TMT bars from corrosion.
Bipolar admixture was used in concrete for corrosion prevention of TMT bars and had a positive impact on time, cost and manpower.
Solvent-free epoxy resin grout was used for anchor plate grouting.
PCE (polycarboxylate)-based admixture was used in concrete for designing workable parameters.
Omega seal expansion joint was used with high-quality neoprene, which benefitted in terms of the time factor and manpower for easy installation.

Equipment required
The project made use of unique equipment, including:

  • Three piling rigs – for pile foundation
  • Six 40-tonne cranes -for pier/pier cap/portal shuttering and de-shuttering
  • Boom placer – for concreting of pier/pier cap/portal
  • Five 20-tonne excavators with rock breaker – for open foundation
  • Five 60-tonne gantries – for loading of segments and I-girder
  • Nine 60-tonne trailers – for transportation of segments from casting yard to site
  • Two 100-tonne modular trailers – for transportation of I-girder
  • Three launching girders and six GSS – for span erection
  • Three 200-tonne cranes – for I-girder erection and segment erection in GSS.

Safe and green
Safety and environment-friendly construction measures were taken to protect the safety and health of every person at site; comply with the relevant statutory and contractual safety, health and environment requirements; have trained, experienced and competent personnel and supervision; maintain plant, places and systems of work that are safe and without risk to health and the environment; provide all personnel with adequate information, instruction, training and supervision; effectively control, coordinate and monitor the activities of all personnel, including contractors, in terms of safety, health and environment and security; and establish effective communication on safety, health and environment matters with all relevant parties.

"Afcons establishes and maintains strong health, safety and environment protocols for any project," says Pai. "We have mandatory, daily briefings by safety officers and the shift in-charge before the shifts every day. For every phase of the project, we planned safety inductions for all workers and employees. All PPE is checked and maintained periodically to ensure the highest safety of people. We have always followed a safety culture and constantly promote it through various awareness sessions, camps, check-ups, etc." Afcons has clocked 12 million safe manhours in the project till date.

What’s more, as this work was undertaken in the city area, all excavated earthwork was properly disposed of at designated locations to ensure it did not affect the environment. Further, standard procedures and protocol were followed at site to reduce energy consumption.

Evidently, the Nagpur Metro is living up to its fast, clean, green promise!

-SERAPHINA D’SOUZA

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Concrete

SCMs play a pivotal role in reducing the carbon footprint

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Vimal Joshi, Assistant General Manager – Quality Control, Wonder Cement, discusses how use of SCMs reduces reliance on clinker while supporting circular economy, creating long-lasting, high-quality infrastructure.

What role do supplementary cementitious materials (SCMs) play in enhancing the performance and sustainability of cement and concrete?
SCMs play a crucial role in enhancing both the performance and sustainability of cement and concrete. By replacing a portion of traditional Portland cement with materials like fly ash, slag and silica fume, we significantly improve the durability, strength and workability of concrete. SCMs react chemically with the calcium hydroxide released during hydration, forming additional calcium silicate hydrate (C-S-H), which enhances the concrete’s long-term strength.
Beyond performance, SCMs also contribute to sustainability by reducing the carbon footprint associated with cement production. By using industrial by-products as raw materials, we reduce the need for energy-intensive clinker production and divert waste from landfills, contributing to an eco-friendlier construction process.
SCMs not only improve the technical properties of cement but also support the broader goals of reducing greenhouse gas emissions and promoting resource efficiency.

How has your company integrated SCMs into its production process, and what challenges have you encountered?
We have successfully integrated SCMs into our production process, making them a key component of our sustainability strategy. We incorporate fly ash, and Performance Improver Limestone to replace a portion of the clinker in our cement, thus lowering our carbon emissions and enhancing product performance. However, the integration of SCMs has presented some challenges, primarily in terms of supply consistency and quality control (such as high moisture content and presence of foreign material in coal fly ash). Since SCMs are industrial by-products, their availability and composition can vary, which requires rigorous quality checks and adjustments to the production process.
Another challenge is achieving the right balance in the cement mix to ensure optimal strength and durability while maximising SCM content. Despite these challenges, we remain committed to increasing the use of SCMs and have developed strong partnerships with suppliers to ensure a reliable and consistent supply of high-quality materials.
Apart from fly ash and performance improvers we are using iron sludge (0.3 per cent to 0.8 per cent) as a substitute for laterite and red mud (1 to 2 per cent) as a substitute for bauxite in the manufacture of clinker without compromising on quality. Both materials are by products of industries with low SiO2 and high R2O3 content (addition of oxides), which helps reduce additive consumption in the raw mix (conserving natural resources) and reduces LSF requirement in stock pile preparation and thus, helping in increasing the available limestone reserves (conservation of natural resources).
We are using chemical gypsum and bed ash gypsum as substitutes to mineral gypsum in cement grinding, both are by-products of the industries that have high purity, which helps in preserving the natural gypsum and also increases the strength of cement and concrete.

Can you share insights on how SCMs such as fly ash, slag, and silica fume impact the durability and strength of concrete in different environmental conditions?
SCMs like fly ash, slag and silica fume significantly enhance the durability and strength of concrete, particularly under diverse environmental conditions. Fly ash improves workability and extends the setting time, making it ideal for mass concrete projects and hot climates. The fine particles fill voids in the cement matrix, reducing permeability and enhancing resistance to sulphate and chloride attack, thus increasing durability. Slag, with its slow hydration properties, improves long-term strength and is particularly effective in reducing thermal cracking in massive concrete structures. It also enhances resistance to aggressive chemicals, making it suitable for marine environments and industrial applications.
Silica fume, known for its ultrafine particles, increases the density of concrete, boosting both compressive strength and durability, especially in harsh environments. By incorporating SCMs, we create concrete that is more resilient to environmental stressors, ensuring longer-lasting structures with reduced maintenance needs.

With the global push for sustainability, how do SCMs contribute to reducing the carbon footprint of cement production?
SCMs play a pivotal role in reducing the carbon footprint of cement production, aligning with the global drive for sustainability. By substituting a portion of clinker, the most energy-intensive component of cement, with SCMs like fly ash and slag, we lower CO2 emissions from the production process. Each tonne of clinker replaced by SCMs reduces the need for limestone calcination, a major source of carbon emissions. SCMs are often industrial by-products, so their use in cement also promotes waste recycling, contributing to the circular economy.
Furthermore, SCMs typically require less energy to process than clinker, resulting in lower overall energy consumption. This shift towards utilising SCMs supports our broader sustainability goals, helping Wonder Cement meet both regulatory requirements and industry benchmarks for environmental responsibility, while providing
high-quality cement products that meet modern construction needs.

What strategies or innovations has your company adopted to ensure a consistent and reliable supply of SCMs, given their reliance on industrial by-products?
To ensure a consistent and reliable supply of SCMs, Wonder Cement has adopted several strategies and innovations. First, we have established long-term partnerships with key industries, such as thermal power plants, to secure a steady supply of fly ash. This collaboration ensures that we can maintain the quality and availability of SCMs despite potential fluctuations in production volumes. Additionally, we have invested in logistics and storage infrastructure to manage the seasonal and location variability of SCMs, allowing us to store and distribute materials as needed.
Another innovation involves the diversification of SCM sources, exploring options like rice husk ash, silica fume, granulated slag, copper slag, steel slag, lead zinc slag and ground granulated blast furnace slag. We also engage in research and development to optimise the performance of SCMs, ensuring that even with variability, the final cement product consistently meets our quality standards. These strategies ensure that we can reliably integrate SCMs into our production process.

Are there specific projects where SCMs have delivered outstanding results in terms of performance or sustainability?
SCMs have delivered outstanding results in various projects undertaken by Wonder Cement, particularly in terms of performance and sustainability. One notable example is our use of SCMs in large infrastructure projects such as bridges, dams and highways, where durability and long-term performance are crucial.
The incorporation of fly ash and performance improvers in these projects has enhanced concrete’s resistance to cracking, sulphate attack and chloride-induced corrosion, ensuring structural longevity.
In terms of sustainability, SCMs have been integral to our low-carbon cement mixes, which have been used in green building projects aimed at reducing the overall environmental footprint. These eco-friendly cement products have not only met but exceeded performance expectations, while significantly cutting down on carbon emissions during production.
By utilising SCMs, we have successfully delivered projects that align with both performance standards and sustainability goals, providing long-lasting, high-quality infrastructure with reduced environmental impact.

How does the use of SCMs align with your company’s broader goals around circular economy and resource efficiency?
The use of SCMs at Wonder Cement aligns perfectly with our broader goals of promoting the circular economy and enhancing resource efficiency. SCMs are typically industrial by-products like fly ash from power plants and performance improver from our own mines, and by incorporating these materials into our cement production, we help close the resource loop. This approach reduces the need for virgin raw materials, lowers waste sent to landfills, and minimises the environmental footprint of our operations. It also enables us to reduce the clinker factor in cement, which is the most carbon-intensive component, thereby contributing to lower CO2 emissions.
Additionally, the use of SCMs extends the life cycle of concrete products, reducing the need for repairs and replacements. This aligns with our commitment to sustainable development, resource optimisation, and supporting the global transition towards more circular, low-waste industrial practices.

What future trends do you foresee in the use of SCMs within the cement industry?
The future of SCMs in the cement industry looks promising, with several key trends likely to shape their development. One trend is the increasing diversification of SCM sources, as industries explore new by-products like rice husk ash, volcanic ash and even recycled construction materials as viable alternatives to traditional fly ash and slag. Another development is the refinement of SCM processing technologies, allowing for more consistent quality and higher substitution rates of clinker without compromising cement performance.
As sustainability continues to drive innovation, we foresee a growing demand for low-carbon cement products, with SCMs playing a critical role in meeting regulatory and market expectations for green construction materials. Additionally, advancements in carbon capture and storage (CCS) technologies could complement the use of SCMs, further reducing the carbon footprint of cement production.
Wonder Cement is keen to stay at the forefront of these trends, continuously evolving our use of SCMs to meet future industry demands.

– Kanika Mathur

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Concrete

SCMs encourage closed-loop systems

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As the cement industry prioritises sustainability and performance, Supplementary Cementitious Materials (SCMs) are redefining standards, explains Tushar Khandhadia, General Manager – Production, Udaipur Cement Works.

What role do supplementary cementitious materials (SCMs) play in enhancing the performance and sustainability of cement and concrete?
SCMs play a crucial role in enhancing the performance and sustainability of cement and concrete. These materials are added to concrete to improve its properties such as strength, durability, and workability, as well as to reduce the environmental impact of cement production. The addition of SCMs to cement reduces the amount of Portland cement required to manufacture concrete, reducing the carbon footprint of the concrete. These materials are often industrial waste products or by-products that can be used as a replacement for cement, such as fly ash, slag and silica fume.
SCMs also reduce the amount of water required to produce concrete, which reduces the environmental impact of concrete production. This is achieved through their ability to improve the workability of concrete, allowing the same amount of work to be done with less water.
In addition, SCMs improve the durability of concrete by reducing the risk of cracking and improving resistance to chemical attack and other forms of degradation.

How has your company integrated SCMs into its production process, and what challenges have you encountered?
The integration of SCMs into cement and concrete production may pose certain challenges in the areas of sourcing, handling and production optimisation.

  • Sourcing: Finding an adequate and reliable supply of SCMs can be a challenge. Some SCMs, such as fly ash and slag, are readily available by-products of other industrial processes, while others such as silica fume or metakaolin may be more difficult to source.
  • Handling: The storage, handling, and transportation of SCMs require special considerations due to their physical and chemical properties. For instance, some SCMs are stored in moist conditions to prevent them from drying out and becoming airborne, which could pose a safety risk to workers.
  • Production optimisation: The addition of SCMs into the mix may require adjustments to the production process to achieve the desired properties of cement and concrete. For example, the use of SCMs may affect the setting time, workability, strength gain, and other properties of the final product, which may require reconfiguration of the production process.
  • Quality control: The addition of SCMs may introduce variability in the properties of cement and concrete, and rigorous quality control measures are necessary to ensure the final product meets the required specifications and standards.

Proper planning, handling and production optimisation are essential in overcoming the challenges encountered during the integration process.

Can you share insights on how SCMs such as fly ash, slag and silica fume impact the durability and strength of concrete in different environmental conditions?

  • Fly ash is a by-product of coal combustion and is widely used as an SCM in the production of concrete. When added to concrete, fly ash reacts with the calcium hydroxide present in the concrete to form additional cementitious materials, resulting in improved strength and durability. Fly ash increases the durability of concrete by improving its resistance to sulphate and acid attacks, reducing shrinkage and decreasing the permeability of concrete. Fly ash also enhances the workability and pumpability of concrete while reducing the heat of hydration, which reduces the risk of thermal cracking. In cold climates, fly ash helps to reduce the risk of freeze-thaw damage.
  • Slag is a by-product of steel production and is used as an SCM because of its high silica and alumina content. When added to concrete, slag reacts with the calcium hydroxide present in the concrete to form additional cementitious materials, resulting in improved strength and durability. Slag increases the durability of concrete by improving its resistance to sulphate and acid attacks, reducing shrinkage and improving the strength of concrete over time. Slag also enhances the workability of concrete, reduces the heat of hydration, and improves the resistance of concrete to chloride penetration.
  • Silica fume is a by-product of the production of silicon and ferrosilicon alloys and is used as an SCM because of its high silica content. When added to concrete, silica fumes react with the calcium hydroxide present in the concrete to form additional cementitious materials, resulting in improved strength and durability. Silica fume increases the durability of concrete by improving its resistance to sulphate and acid attacks, reducing permeability, and improving abrasion resistance. Silica fume also enhances the workability of concrete, reduces the heat of hydration, and improves the resistance of concrete to chloride penetration.

Overall, the use of SCMs such as fly ash, slag and silica fume can significantly improve the durability and strength of concrete in different environmental conditions. Their impact on concrete varies depending on the availability, physical and chemical properties of the specific SCM being used and proper testing and engineering analysis should be done for each mix design in order to optimise the final product.

With the global push for sustainability, how do SCMs contribute to reducing the carbon footprint of cement production?
SCMs provide an environmentally friendly alternative to traditional Portland cement by reducing the amount of clinker required to produce cement. Clinker is the main ingredient in Portland cement and is produced by heating limestone and other raw materials to high temperatures, which releases significant GHG emissions. Thus, by using SCMs, less clinker is required, thereby reducing GHG emissions, energy use and the environmental impact of cement production. Some SCMs such as fly ash and slag are by-products of other industrial processes, meaning that their use in cement production reduces waste and enhances resource efficiency. Moreover, the use of SCMs can enhance the properties of concrete, thereby increasing its durability and service life which helps to further reduce the overall embodied carbon of the structure.
In short, the use of SCMs contributes to reducing the carbon footprint of cement production by improving the efficiency of resource utilisation and reducing greenhouse gas (GHG) emissions during the production process. This has led to an increased demand for SCMs in the construction industry, as environmental concerns and sustainable development goals have become more prominent factors in the selection of building materials.

What strategies or innovations has your company adopted to ensure a consistent and reliable supply of SCMs, given their reliance on industrial by-products?

  • Developing partnerships with suppliers: Many cement and concrete manufacturers establish long-term partnerships with suppliers of SCMs. These partnerships provide a reliable supply of high-quality SCMs, improve supply chain efficiency, and often provide access to new sources of SCMs.
  • Advanced SCM processing techniques: Many companies are investing in advanced processing techniques to unlock new sources of high-quality SCMs. Advanced processing techniques include new separation processes, calcination techniques, and chemical activation methods.
  • Alternative SCM sources: Many companies are exploring alternative SCM sources to supplement or replace traditional SCMs. Examples include agricultural by-products such as rice hull ash or sugar cane bagasse ash, which can be used in place of fly ash.
  • Quality control measures: Strict quality control measures are necessary to ensure consistent quality of SCMs. Many companies use advanced testing methods, such as particle size analysis, chemical analysis, and performance testing, to validate the quality of SCM materials used in production.
  • Supply chain diversification: Diversifying suppliers and SCM sources is another way to ensure a reliable supply. This reduces the risk of supply chain disruptions caused by factors such as natural disasters, market changes, or geopolitical risks.

The strategies and innovations adopted to ensure a consistent and reliable supply of SCMs include establishing long-term partnerships with suppliers, investing in advanced processing techniques, exploring alternative SCM sources, implementing strict quality control measures, and diversifying supply chains. By implementing these approaches, we ensure that use of SCMs in cement production is an effective and viable solution for reducing the environmental impact of operations

How does the use of SCMs align with your company’s broader goals around circular economy and resource efficiency?
Here are some ways in which the use of SCMs supports these goals:

  • Reducing waste: The use of SCMs, such as fly ash and slag, diverts significant quantities of industrial waste from landfills, turning it into a valuable resource that can be used in construction. This helps to reduce waste and conserve natural resources.
  • Reducing carbon emissions: Cement production is a significant contributor to greenhouse gas emissions, and the use of SCMs can significantly reduce the amount of cement required in concrete mixtures. This helps to reduce the carbon footprint of construction activities and move towards a low-carbon economy.
  • Enhancing resource efficiency: The use of SCMs can reduce the demand for raw materials, energy, and water in the production of concrete. This not only conserves natural resources but also reduces the costs associated with the extraction, transportation and processing of these materials.
  • Closing the loop: SCMs encourage closed-loop systems in the construction sector, where waste materials from one process become input materials for another. This can improve the efficiency and sustainability of the construction industry.
  • Supporting sustainable design practices: The use of SCMs can support sustainable design practices by improving the durability and performance of structures while also reducing their environmental impact. This supports a circular approach to design, construction and operation of buildings and infrastructure
    that improves their social, economic and environmental sustainability.

What future trends or developments do you foresee in the use of SCMs within the cement industry?
Future trends in the use of SCMs within the cement industry are likely to focus on: increased utilisation of diverse waste-derived SCMs, development of new SCM sources to address potential shortages, advanced characterisation techniques to optimise SCM blends and data-driven approaches to predict and optimise SCM usage for reduced carbon footprint and improved concrete performance; all driven by the growing need for sustainable cement production and stricter environmental regulations.
Key aspects of this trend include:

  • Expanding SCM sources: Exploring a wider range of industrial byproducts and waste materials like recycled concrete aggregate, activated clays and certain types of industrial minerals as potential SCMs to reduce reliance on traditional sources like fly ash, which may become increasingly limited.
  • Advanced material characterisation: Utilising sophisticated techniques to better understand the chemical and physical properties of SCMs, allowing for more precise blending and optimisation of their use in cement mixtures.
  • Data-driven decision making: Implementing machine learning and big data analysis to predict the performance of different SCM combinations, allowing for real-time adjustments in cement production based on available SCM sources and desired concrete properties.
  • Focus on local sourcing: Prioritising the use of locally available SCMs to reduce transportation costs and environmental impact.
  • Development of new SCM processing techniques: Research into methods to enhance the reactivity and performance of less readily usable SCMs through processes like activation or modification.
  • Life cycle analysis (LCA) integration: Using LCA to assess the full environmental impact of different SCMs and optimise their use to minimise carbon emissions throughout the cement production process.
  • Regulatory frameworks and standards:Increased adoption of building codes and industry standards that promote the use of SCMs and set targets for reduced carbon emissions in cement production.

– Kanika Mathur

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Concrete

The use of AFR plays a critical role in our strategy

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Rajesh Kumar Nayma, Assistant General Manager – Environment, Wonder Cement, shares the company’s ambitious commitment to reducing emissions through advanced technology and alternative fuel use, thereby driving significant change in the cement industry.

How does your company address the environmental impact of cement production, particularly in terms of reducing emissions?
Wonder Cement Limited (WCL) has played a vital role in Indian infrastructure development and focuses towards a more sustainable future, including environment protection, clean energy and water positivity. The organisation is a firm believer in putting a positive impact on the environment. Environment and sustainability is a core value that drives our operations. We are committed to minimising the environmental impact from cement production, particularly when it comes to emissions. We do the impact analysis due to operation of the units being carried out at design stage level to ensure minimum impact on the environment i.e. air, water and land. Equipment selection is done accordingly taking various measures to ensure no fugitive emission, stack emission, water pollution and soil degradation such as installation of best-in-class air pollution control equipment (ESP’s Reverse Air Baghouse); bag filters at all the material transfer points; provided covered storage facilities/storage silos to maintain ambient air quality; fugitive emission and stack emission well within the prescribed emission Norms, Selective Non Catalytic Reactor (SNCR) for control of NOx Emission; and preventive routine maintenance of air pollution control equipment are carried out. By taking these measures, WCL ensures emissions are well below the stipulated norms for particulate matter, SO2 and NOx.

We are focusing on reducing the GreenHouse Gases (GHG) emissions, too. Due to our operations, we have done GHG Invertisation, which aims to achieve Net Zero by 2060, in line with the nation’s commitment in COP-26.
We have Zero Liquid Discharges facilities across all our units. Being dry process cement manufacturing units, the wastewater generation in our units is very low in quantum and the implemented closed-loop systems help to reuse process water and minimise fresh water consumption. WCL is reusing 100 per cent STP/ETP water in its process, greenbelt development and dust suppression at its integrated cement plant and split grinding units.

What measures have been implemented to monitor and control emissions of CO2, NOx, and particulate matter during the cement manufacturing process?
We have installed an Online Continuous Stack Monitoring System (OCEMS) in all the process stacks along with PTZ cameras and Continuous Ambient Air Quality Monitoring Systems (CAAQMS) in all our operating units. Real time data of OCEMS/CAAQMS is transmitted to SPCB/CPCB servers, and also to our control systems, which enables us to take corrective action on priority.
The major pollutants through air are particulate matter and gaseous emissions. The emissions of particulate matters from all the stacks are maintained within the prescribed norms by installing bag house, bag filters and electorstatic precipitator (ESP) at all major sources of air pollution i.e. raw mill, kiln, clinker cooler and coal mill cement mills and captive power plant (CPP).
We have also installed SNCR technology along with a low NOx burner to reduce NOx emissions effectively to keep the same in the prescribed norms and lime dosing systems have been installed in the power plants to ensure SO2 emission within the prescribed norms.
We use alternative fuels and raw materials (AFR) in order to increase our green energy portfolio, to reduce the clinker factor and to reduce the power/energy consumption per tonne of clinker/cement. The installation of WHRB in all the operating kilns has further helped in cutting down the CO2 emissions.

Can you elaborate on the role of alternative fuels and raw materials in reducing the environmental footprint of cement production?
The use of AFR plays a critical role in our strategy to reduce the environmental footprint of cement production. By substituting traditional fossil fuels with waste-derived alternatives like biomass, refuse-derived fuel (RDF) and industrial by-products, we significantly lower CO2 emissions and reduce the demand for natural resources.
The utilisation of supplementary cementitious materials (SCMs), such as fly ash, helps in reducing clinker consumption, which is a major source of carbon emissions in cement production. This not only decreases our reliance on energy-intensive processes but also promotes waste recycling and resource efficiency. AFR adoption is an integral part of our commitment to the circular economy, ensuring that we minimise waste and optimise the use of materials throughout the production cycle, ultimately contributing to a more sustainable and eco-friendly cement industry.
WCL is exploring transitioning from fossil fuels to cleaner alternatives like biofuels or hydrogen or RDF/plastic waste/other hazardous waste. Till date, 5 per cent TSR has been achieved, while the intent is to achieve more than 20 per cent TSR. WCL is utilising the hazardous and other waste as an alternative fuel or raw material. We have used more than 3 lakh metric tonne of hydrogen waste and other waste in FY-2023-24.

How does your company approach waste management and recycling to minimise environmental harm?

WCL is focusing on the 3 R’s – Reduce, Reuse and Recycle. We focus on optimum utilisation of natural resources and reuse of said resource as well as recycling of the waste material generated from our operations.
We are contributing to reduce the legacy waste generated in our municipalities and we have co-processed more than 50000 tonnes of RDF/plastic waste. Additionally, we are sending other waste generated at our facilities such as used oil / used lead acid batteries / e-waste to authorised recyclers. We are focused on targeted reduction in waste generation.
We are also utilising alternative raw materials. which are the waste from other industries such as red mud, chemical gypsum, iron sludge and ETP sludge to substitute natural resources.
WCL is also increasing the use of recycled content of plastic in PP bags.
We have met our EPR target for plastic waste introduced in the market for FY 23-24 through co-processing of plastic waste in its kiln. Additional EPR credit will be traded for this in the market.

What are the biggest challenges your company faces in achieving compliance with environmental regulations, both locally and globally?
WCL is committed toward 100 per cent compliances to applicable rules and regulations and having dedicated resources to do so, when we talk about the challenges WCL faces in complying with environmental regulations is the constantly evolving nature of both local and global environmental rules and regulation which further leads to strength. While we are committed to adhering to stringent regulations, keeping up with the rapid changes in environmental laws requires continuous upgradation in technology and processes. Another challenge is the high capital investment needed for adopting cleaner technologies, such as De_Sox System / SNCR / Up-gradation of ESP /bag house and carbon capture systems.
Additionally, the availability of AFR can be inconsistent, making it difficult to achieve consistent reductions in GHG emissions. Despite these challenges, WCL remains committed to sustainability and continuously collaborates with regulatory bodies and industry experts to stay ahead of compliance requirements. We also invest in research and development to innovate our production processes, ensuring that we not only meet but exceed environmental compliances.

What technological innovations or process optimisations has your company adopted to lower greenhouse gas emissions?
WCL has adopted several technological innovations and process optimisations to lower greenhouse gas emissions. One of the key initiatives is the installation of 45 MW waste heat recovery systems, which capture excess heat from the production process and convert it into energy, reducing the overall carbon footprint. We have also introduced advanced burner technology with lower NOx emissions and optimised energy consumption and presently we are less than 47 KWh/tonne of clinker, which is one of the best in the cement industry.
The deployment of energy-efficient vertical roller mills (VRM) for clinker grinding also contributes to reducing energy consumption and emissions. These innovations are part of our broader commitment to sustainability and are continuously enhanced to meet global environmental standards.
WCL is focusing on investing in renewable energy sources like solar or wind power to meet the electricity needs. We have installed a solar power plant at our Nimbahera plant and Jhajjar grinding unit as well as 15 MW windmills at Pratapgarh, for our grinding units located at Aligarh, Uttar Pradesh and Dhule Maharashtra. We have renewable power purchase agreements to source renewable energy, which will replace approximately 50 to 60 per cent of energy demand from the grid, further leading to reducing the GHG emissions.
WCL is taking various operational/capex measures to reduce the energy requirement like installation of VFD, optimisation of differential pressures across bag filters and optimisation of kiln operation to get maximum output.

How does your company engage with stakeholders, including local communities and environmental agencies, to ensure transparency and sustainability in your operations?
WCL has a well-defined approach for identification of stakeholders, which is done after considering the material influence each group has on the company’s ability to create value (and vice-versa). The objective of stakeholder engagement is to foster connections, build trust and confidence and buy-in for your company’s key initiatives. This can also help us mitigate potential risks and conflicts with stakeholders.
Stakeholder engagement is done is to understand the needs and expectation of anyone who has a stake in our company, based on which we can develop our strategy and identify our focus areas such as:

  • What long-term goals has the company set in terms of reducing emissions
  • What steps are being taken to achieve them
  • What are the key focus areas to take society along with us

WCL places great emphasis on engaging with stakeholders, including local communities, environmental agencies and industry experts, to ensure transparency and sustainability. We conduct regular environmental audits and share our findings with relevant regulatory bodies to ensure compliance. Our CSR initiatives are closely aligned with community needs, particularly in areas like water conservation, afforestation and waste management, health, education and women empowerment, which directly impact the local environment.
We maintain an open dialogue with local residents to address their concerns about air quality, emissions and resource use and carry out need based assessment and accordingly design our CER/CSR programme and further implement the same.
Additionally, WCL participates in various industry forums and collaborates with environmental agencies to stay ahead of regulatory changes and adopt best practices. Transparency is key to building trust, and we ensure that all stakeholders are kept informed about our sustainability initiatives through periodic reports and community outreach programs. This collaborative approach ensures that we maintain a positive environmental and social impact.

What long-term goals has your company set in terms of reducing emissions, and what steps are being taken to achieve them?
WCL has set ambitious long-term goals to significantly reduce emissions in line with global climate targets. One of our primary objectives is to achieve net-zero carbon emissions by 2060, with interim goals to reduce CO2 intensity by 25 per cent by 2040 through increasing Green Energy Portfolio from present 41 per cent to 70 per cent, AFR and green hydrogen 3 per cent to 40 per cent, reduction in clinker factor from 79 to 60 per cent and CCUS and electrification of the kiln, introduction of LC3 and PLC cements based on techno-economic feasibility.
To achieve these targets, we are investing to develop facilities to feed more AFR, which helps to reduce dependence on fossil fuels and natural resources and lower carbon emissions. We are also exploring carbon capture and storage (CCS) technologies to capture CO2 emissions at their source. WE are committed to achieving its long-term sustainability goals and contributing to the global effort to combat climate change.

– Kanika Mathur

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