Connect with us

Concrete

Opportunities for MSW in India

Published

on

With urbanisation and industrialisation increasing around the world (despite a temporary COVID-19 setback), the issue of waste management and particularly of municipal solid waste will be a critical challenge to sustainable development.

Global waste production is expected to reach 27 billion tonnes per year by 2050, a third of which will be generated in Asia.1 India will be a major contributor: it currently generates more than 150,000 tonne per day of solid waste, approximate 54.75 million tonne (MT) per year.2

The government steps in To tackle this growing pile of waste ??much of which has traditionally ended up in landfills ??the Indian government has issued two directives:

Guidelines on Usage of Refuse Derived Fuel in Various Industries

Central Public Health and Environmental Engineering Organisation; Ministry of Housing and Urban Affairs (September 2018).

Guideline Document Uniform Framework for Extended Producers Responsibility

Under Plastic Waste Management Rules, 2016; Ministry of Environment, Forest and Climate Change (June 2020)

The first of these ??which is now in force ??aims to prevent the landfill of waste that are ??ombustible in nature but are not recyclable such as soiled paper, soiled cloth, contaminated plastics, multi-layer packaging materials, other packaging materials, pieces of leather, rubber, tyre, polystyrene, wood, etc.??

The second of ??which is still in consultation stage ??deals with plastic waste. Among other things, it will make companies that use plastic packaging for their products responsible for collecting and disposing of that packaging.4 One solution to both of these challenges is the substitution of fossil fuels by alternative refusederived fuels (RDF) at cement plants and thermal power plants.

The use of waste as an alternative fuel in the cement industry has a longstanding history, particularly in Europe, where substitution rates can reach well over 50 per cent and companies are pushing to reach 100 per cent. This is supported by generous gate fees paid by waste producers to cement companies and tight carbon emissions regulations (some alternative fuels are considered carbon neutral under EU regulations). Indeed, the use of RDF and other alternative fuels is acknowledged as a key step in the cement industry?? path to carbon neutrality, alongside energy efficiency and the use of supplementary cementitious materials.5

To encourage the use of RDF, the expenses so incurred for transportation of RDF, beyond 100 km distance may be booked by industries under their Corporate Social Responsibility (CSR) commitment as per Section 135 of the Companies Act, 2013.3 RDF in India

The Cement Manufacturers Association (CMA) had expressed its commitment towards disposal of wastes and plastics and use of alternate fuels and raw materials.6 The past President (2018 to 2020) of CMA, Mr. Mahendra Singhi, commented; ??he Indian cement industry has been able to use almost 75 million tonnes of waste as a replacement of raw materials and fuels??

Mr. Singhi, who is also the MD and CEO of Dalmia Cement (Bharat) Ltd, added that the Indian cement sector has played an important role in the transition to a low carbon economy and is fully committed towards efficiency in terms of clean and green operations.

As part of the new guidelines, cement companies are now required to utilise RDF in any kiln located within 400 km of an RDF production facility.

Unusually, it is also the cement companies that are required to bear the cost of this rule, for example; there are no gate fees payable for taking waste and cement companies have to pay the transportation fees for the first 100 km radius of the plant.

Managing the increasing quantity of MSW generating in India is a big challenge. A high percentage of MSW including non-recyclable combustible fraction ends up in landfills. In spite of enough demand a supply of RDF by vibrant private sector in waste management and cement industry and existence of enabling policy framework of SWM Rules 2016, current on ground situation is not very promising due to several challenges as depicted below:

The regulation envisages a rising scale of substitution rate from 6 per cent in the first year up to 15 per cent in the third year, although an evaluation of the amount of available RDF vs the energy needs of the cement industry suggest that a thermal substitution rate of 7.1 per cent may be the maximum achievable (Table 1).

The data captures the details of daily exposed garbage. There is a significant quantum of legacy wastes which needs to be processed to make it usable RDF.

A Partner for Sustainable Waste Management

The new regulations position the cement industry as a key partner in solving India?? waste challenges.

However, there are certain challenges in its processing. Notably, the quality of RDF currently produced in India is much lower than that of in other regions, with lower calorific value and much higher moisture content. In worst scenario the ??ombustible wastes??which ??hould at least be heat neutral??and ??hould not affect the Clinker quality??

The requirement for Indian cement companies to finance the capex required to begin using RDF has also focused the market on economically viable, simple and standard alternative fuels feeding systems to meet the possible substitution rate up to 7 per cent. Going forward, to increase substitution rates, the cement industry needs accuracy in feeding and dosing system, efficient process and alternative fuel material analysis. To support these requirements, cement industry demands proven technologies like; rotor weigh-feeders, a HOTDISC? Combustion Device with solid alternative fuel ash exaction possibilities and utilisation of solid alternative fuel ash, chlorine gas by-pass system and utilisation of chlorine rich dust.

Cement manufacturers like, Dalmia Cement, which targets higher levels of alternative fuel substitution rates, reportedly up to 100 per cent, as part of a corporate ambition to manufacture the greenest cement in the world.7 FLSmidth is supporting this ambition as the supplier of Dalmia Cement?? new plant at Rajgangpur, where the equipment and design of the plant were carefully selected to maximise the potential for alternative fuels and raw materials use, as well as to reduce energy efficiency and heat loss.Tackling plastics Plastic waste has garnered recent attention due to littering of crucial ecosystems, most notably that of oceans. According to one estimate, between 4.8 MT and 12.7 MT of plastic waste enters the oceans each year.8 Reversing this damaging pattern has been recognised as integral to sustainable development and is a key target of the fourteenth UN Sustainable Development Goal.9 As part of the solution to this challenge, the Indian government has introduced rules that make use and disposal of plastic packaging as the responsibility of the generator. This impacts the Indian cement industry in a couple of different ways.

Firstly, as a user of plastic packaging for its products ??and with bagged cement playing a larger role in the Indian cement market than in other regions ??the industry is faced with the need to set up systems to collect that plastic or switch to alternative paperbased packaging.However, the industry may also find itself (again) as a crucial part of the solution, due to its ability to utilise plastic waste as an alternative fuel. One opportunity arising from the regulations may be for the cement industry to partner with others that use plastic packaging to create efficient collection and processing systems for plastic waste that sees the non-recyclable elements made available for use in cement kilns.

Conclusion

Waste is a serious challenge to sustainable development. Finding ways to use the non-recyclable elements in a productive way is therefore key to

setting humanity on a path to a cleaner, greener future. With its huge capacity to utilise RDF, the cement industry has a vital role in doing this. And the benefits of doing so reach far beyond (emptier) landfills. RDF substitution of fossil fuels reduces both the cement industry?? carbon emissions, as well as the necessity to mine fossil fuels. Supporting the use of alternative fuels is therefore a priority for FLSmidth through our MissionZero ambitions to enable zero-emissions cement production.

As part of this, we have committed to providing cement producers the solutions needed to operate with 100 per cent alternative fuels. This goes beyond the provision of equipment to include our significant process experience ??from initial reception and handling of alternative fuels through their impact on conditions in the kiln and on the final chemistry of cement. This deep understanding of the process enables us to assist any plant in solving the challenges that alternative fuels bring ??whether just starting out or reaching for 100 per cent.

References

1. KUMAR, S., et at., 2017, ??hallenges and opportunities associated with waste management in India?? R. Society open sci. https://doi. org/10.1098/rsos.160764

2. AGGARWAL, M., 2019, ??umbai and Delhi generate most solid waste among metro cities??The Wire. https://thewire.in/environment/indias-megacities-mumbai-and-delhi-sitting-ona-pile-of-waste

3. Ministry of Housing and Urban Affairs, 2018,Guidelines on Usage of Refuse Derived Fuels in Various Industries, p. X.

4. This principal is known as ??xtended Producer Responsibility??

5. For example, see: IEA, 2018, Technology Roadmap:

Low-Carbon Transition in the Cement Industry, p. 28.

6. Indian cement industry commits towards waste management. https://www.outlookindia.com/ newsscroll/indian-cement-industry-commitstowards- waste-management/1630881

7. Global Cemfuels, 2019, ??almia Cement commits itself to 100 per cent RDF and biofuels by 2030?? https://www.cemfuels.com/news/item/3150-dalmia-cement-commits-itself-to-100-rdf-andbiofuels- by-2030

8. JAMBECK, J.R., et al., (2015) ??lastic waste inputs from land into ocean?? Science vol. 347, issue 6223, pp. 768-771. https://science.sciencemag. org/content/347/6223/768

9. Goal 14: Conserve and Sustainable Use theOceans, Seas and Marine Resources. https://www.un.org/sustainabledevelopment/oceans/

ABOUT THE AUTHOR: The article is authored by Dr Alka Mishra, Head of Sustainability Solutions, FLSmidth India

Continue Reading
Click to comment

Leave a Reply

Your email address will not be published.

Concrete

Precast use of concrete promotes sustainability

Published

on

By

Vijay Shah, Managing Partner, India Precast, advocates the use of precast concrete as he puts forth details about its manufacturing, uses and methods while emphasising the sustainability of the product.

Explain the process of casting concrete in shapes and what is the grade of concrete used for making these shapes?
Precast casting concrete elements are manufactured with the required steel reinforcement either in formwork, moulds or on steel plates with side shuttering etc. The concrete cast is made at a different location and is then transported to the site. Precast elements are made of minimum M20 to M50 grade of concrete.

What is the difference between precast and cast in-situ as uses of concrete?

  • The use of concrete in the precast method and the cast in-situ method differs widely based on many factors.
  • Precast concrete shapes are cast at a different location and are then transported to the site where construction work takes place while with the cast in-situ process, concrete is poured on-site.
  • Curing of precast concrete is fast as it takes place under ideal and controlled conditions while the cast in-situ concrete takes relatively longer to get cured but can be easily used for two-way structural systems.
  • For the precast concrete, the process is easy to do and is repeatable as the same moulds or framework can be used. This increases the value of construction and derives more value
  • while cast in-situ adapts building shapes and post tensioning.
  • The work and rework in the usage of precast shapes is less, thus, reduces cost at the site
  • while with the cast in-situ method there is a requirement of space allotment for concrete mix and necessary add-ins, that is added cost for the construction job.

Tell us about prestressed and reinforced concrete.
Prestressed concrete is a combination of high strength concrete and tensioned steel strands. This combination makes a strong structural unit that is useful in building roof slabs, bridge girders etc. Reinforced concrete is manufactured from a combination of high strength concrete and normal reinforcement bars.

Tell us more about the precast elements manufactured, their shapes and sizes.
Precast is one of the best ways to rapidly build industrial buildings, commercial buildings, affordable housing, mass, EWS, LIG housing, schools, hospitals, public buildings, agriculture railways, stadiums, sport centres, parking, bridges, airports etc. They have a higher productivity and quality set at industry level.
Various types of precast elements manufactures are:

  • Solid load bearing floor slabs, load bearing walls, facades, sandwich wall panels and cladding panels
  • Floor and roof slabs are made from prestressed load bearing hollow core concrete slab and ribbed slabs. They are also made from half floor slab or semi-finished floor slab with a lattice girder
  • Precast stair cases, balcony, toilet pods, lift shafts, water tanks
  • Prestressed lintel, frames, beams, columns and double-tee beams
  • Internal partition walls are made with light-weight hollow core wall panels instead of AAC blocks or bricks
  • Boundary walls, fencing poles, U-drainage or trenches, box culvert etc.

What is hollowcore concrete flooring and what is its lifespan?
Hollowcore slabs are precast, prestressed concrete elements that are generally used for flooring. Some of the advantages of using these flooring are longer lifespans and no propping, flexibility in designs, faster construction, lightweight structures, fire resistant structures, high load capacities and units manufactured specific to the project.
The maximum span of hollowcore floors will depend on the floor depth and the specific loadings imposed on the floor.

What are the quality standards followed while making precast shapes for any project?
Quality control is a very important aspect in the process of making precast concrete shapes. It is imperative to make precast shapes as per the exact requirement provided by the engineers and the construction party. To maintain the quality of product from our end,

  • We ensure there are quality control systems and procedures in place along with a quality assurance plan. Our programme consists of tests, trials, and general procedures for acceptance.
  • There is a laboratory and related facilities, which are required for the selection and control of the quality of materials and workmanship. The central quality laboratory is used for various quality control tests like cube test, workability test, slump test, sieve analysis etc. The materials used for making the final precast shapes also has to be shared for testing to various third-party laboratories with an advance intimation.
  • All the necessary tests are carried out in respective batching plants or sites depending on the use of concrete at our facility.
  • Documentation for all the tests conducted and their reports is maintained in records, for references and submission to the relevant authorities and the users of the same.

As precast use of concrete is conducted in a dedicated space and is in a monitored environment, it becomes easier to maintain high quality due to its repeatability factor. The necessary general precast machinery and moulds, steel tables, concrete batching and dispensing equipment, vibrating and finishing equipment and dedicated labour team help maintain the higher quality standards as compared to cast in-situ use of concrete.

How do you incorporate sustainability in the process of precasting?
Precast use of concrete promotes sustainability with its repeatability factor. There’s more planning involved in the process and equipment like the moulds, vibrating machine, finishing machine are all reusable elements of the process.
As mentioned, there is planning in precast use of concrete where only the required measure of concrete is mixed and poured into moulds that are made to precision as per the requirement of the project. The quantity is also previously defined, which means there is reduced to zero wastage of material.
This waste reduction leads to lesser needs of cleaning and clearing equipment, which may further be fueled by other energy sources. Thus, precast concrete, by large, is a sustainable means of building.

What are the advantages of using precast concrete?
There are multiple advantages of using a precast structure for any project like cost efficiency, speed, versatility, safety, sustainability and beauty.
This includes:

  • The use of precast improves the quality and lifespan of any building
  • It reduces the time of building, thus reducing the costs involved for all the other equipment and labour that goes in to the project, thus, proving to be cost effective
  • The maintenance of a precast is lower due to its high quality and durability that is ensured while it is cast
  • This method of using concrete is a sustainable option due to its repeatability

What are the major challenges you face in the process of making precast shapes and in their transportation?
The precast industry plays on volume and repetition. This is one of the major challenges as well.
The requirement of having to repeat the process
that contains a large volume of mixed concrete and getting the same perfection in the shapes is a cumbersome process.
The initial investment in setting up the precast plant and acquiring all equipment and moulds is high. With bulk shapes to be transported from one place to another and the requirement for site space and handling, this time of concrete use is more suitable for tier 2 and tier 3 cities.

How do precast elements or shapes help in the profitability of a construction activity?
As precast concrete is made at a different location than the construction site, the other jobs keep going on at the site and then the precast shapes are placed there. This reduces construction time to up to one-third to one-fifth as compared to cast in-situ concrete, thus, reducing cost of the construction.
Construction maintenance is reduced as the quality of their precast structures are monitored and carefully administered at the plant level. This means it adds to the reliability, durability, accuracy, and ability to produce architectural elements in any building adding to its quality and strength. Precast also provides insulation, thermal inertia and fire resistance and the possibility of integration with MEP (Mechanical, Electrical and Plumbing) from the start of the project.

How can precast concrete contribute towards affordable mass housing in India?
Defined shapes and technical requirements in precast concrete helps reduce the waste and increase the repeatability factor, thus, reduces the cost and time for any construction or building project. Higher control on quality, less time consumer leads to lesser need of labour and equipment on-site, which also adds to the profitability of the structure.
All factors combined bring down the overall cost of the project, leading to that benefit translating to the end consumer and bringing a surge of affordable mass housing in India.

-Kanika Mathur

Comparison Between Cast-in-situ (conventional method) versus Technology Drive Precast

Sr. No Criteria Conventional Construction Precast Construction 3D Modular/ Panel & Hollow Core Slab.
1 Natural resource consumption High 30 per cent saving
2 Labour Problem Heavy labour problem while work in progress Less labour required
3 Dependability on skilled labor 60 per cent Dependability
4 Time consuming Verv High Fast track
5 Initial investment Low High
6 Finishin Normal Excellent
7 Quality production Poor Excellent as factory based.
8 Material wastage High Least
9 Speed/ Productivity Low Excellent
10 Strength Good Excellent
11 Durability Low High
12 Structure weight/ Deed load Very heavy Reduced
13 Brick Block and Plastering Required No Need
14 Service like Electrical, plumbing & sanitary Break, Provide & Re-build Pre-embedded

Continue Reading

Concrete

The age of concrete blocks can be up to a 100 years

Published

on

By

Nikita George, Director Operations, APCO Concrete Blocks and Allied Products, takes us through the manufacturing process of concrete blocks and its composition and also specifically discusses their patented product – cellular blocks.

Tell us about the type of concrete blocks that your organisation manufactures.
We manufacture mainly solid and cellular concrete blocks. The cellular block is our patented product, which has become increasingly popular due to its high utility value in the construction process. We are also gearing up to launch our new line of pavers and kerb stones by the end of August.

What is the composition of each type of block and what are their strengths?
Blocks constitute of mainly three items:
Cement,

  • Manufactured Sand and Stone Aggregates Our patented cellular blocks have a vast set of benefits:
  • Lightweight: The cellular block is between 8 to 9 kg lighter than the solid block. This not only increases the productivity of the labour but also helps in reducing the overall steel requirement for the project.
  • Thermal insulation properties: With the erratic weather conditions in India today, cellular blocks help in maintaining thermal insulation properties within the building. In a recent experiment conducted on a building, which used the cellular blocks, a marked reduction in temperature by three degrees was recorded.
  • Sound insulation properties: Due to the hollow nature of these concrete blocks, the product is able to cut the decibel levels by 14 per cent.
  • Compressive strength and water absorption properties: The cellular blocks exceed the ISO parameters for compressive strength and water absorption.

How do you ensure quality standards for the concrete blocks manufactured?
With our 50 years of experience in the concrete blocks manufacturing industry, we have continually evolved and tried our best to stay relevant with the international quality standards. Quality control begins with procurement of good quality raw material. Fortunately, we have our own crushers to cater to our production units. This helps us negate undesirable raw materials. State of the art machinery and a strong base of SOP help mitigate errors. Above all, of these we have a skilled set of managers who have over 25 years of experience in the concrete blocks field.

Tell us about the sustainability and environmental benefit while manufacturing and while using these blocks in construction?
The blocks that we manufacture follow the highest quality parameters that give a very long life span. When used in building, the age of concrete blocks can be up to 100 years. The blocks used in these buildings at the time of demolition can be re-crushed and used to manufacture the same product again. And since concrete blocks are one of the strongest products available in the market, the on site damages are virtually zero. Unlike native methods of concrete production, we use only M-sand. There is no usage of river sand hence, safeguarding our environment. Also, as mentioned before, concrete blocks can be reused even after the lifespan of a building. This cuts down on further usage of raw materials.

What are the key benefits that any builder can get from using your concrete blocks?
The concrete blocks industry to a large extent can still be categorised in the unorganised sector. Due to this, there is a lot of disparity in pricing and quality in the market. At APCO, with our 50 years of experience, we have won the trust of our customers by consistently proving the highest quality of our products and on-time delivery.
With our 5 production units strategically located around Bangalore city, we have the capability of producing up to one lakh blocks per day. This allows us to consistently supply large quantities to our customers. Our customers can also be assured that the quantity of blocks that leave our plants is the same quantity that will be unloaded at the site.
Apart from this as mentioned in the earlier answers, our cellular blocks host a wide range of benefits during and even after the construction of a building.

How do these concrete blocks contribute to the profitability of construction?
When APCO came into the market in the early ’70s, the construction industry was heavily reliant on the traditional clay bricks. It took us about 10 years before we got our first big break. And since then, the construction market has not looked back. There have been multiple competitors in the walling solutions market but in terms of pricing and quality no other product comes close. Most people build a house once. At APCO, we believe in making that house a home. We provide unrivalled quality and a fair price to all our customers!

What does the near future hold for APCO Concrete Blocks and allied products?
We will be launching our new product line of pavers and kerb stones by August and we are working towards APCO being present in a few more states around India.

Kanika Mathur

Continue Reading

Concrete

Effects of Macronomics

Published

on

By

In any industry, it always helps to take into account the macro perspective as it aids one in navigating the broader economic trends. As per the assessments of the April-June quarter (Q1), India’s gross domestic product (GDP) increased 13.5 per cent, which was lower than RBI’s estimated 16.2 per cent. A fiscal deficit of Rs 3.41 trillion was noted during the April-July period this financial year.


Moody’s Investors Service has revised India’s economic growth projection for 2022 to a reduced 7.7 per cent. The downward revision is due to rising interest rates, an uneven monsoon and global demand slowdown, which is not surprising as the Russia-Ukraine war continues to cast its shadow. The eight core infrastructure sectors, including cement, slowed down to 4.5 per cent in July, which afforded the service sector to shine in the first quarter.


Taking a bird’s eye view of the cement sector, the upward moving trends are looking promising and that has kept optimism buoyed amongst the players. Monsoon is a tricky time for the cement industry as construction takes a backseat and price fluctuations in cement are rife.

As per Kotak Institutional Equities report, cement prices have declined about a percent sequentially in the second quarter. Cement price was recorded at Rs 384 per 50 kg bag in August pan-India. In spite of a sluggish season, the demand is likely to soar in the coming months, and the key players in the industry are anticipating robust growth.


There is a lot that’s underway for cement manufacturers in terms of alternative raw materials, energy efficiency and eco-friendly processes. Given the infrastructure and construction boom that India is witnessing today, the cement segment is likely to perform well. However, the challenges that the sector faces are unique to it, and it remains to be seen how cement brands will innovate to overcome them.

Continue Reading

Trending News

© COPYRIGHT 2021 ASAPP Info Global Services Pvt. Ltd. All Right Reserved.