Concrete

Concrete Making Materials

Published

8 years ago

April 30, 2018

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Cement is never used as cement alone but is always converted to a value-added product in practice. Therefore application of cement becomes extremely important. The cement producers have a dedicated department that looks into the applications of product. Now onwards, we shall try and cover it through a series of articles in a structured way.
Construction aggregate, or "aggregate", is a broad category of coarse to medium grained particulate material used in construction that includes sand, gravel, crushed stone, slag, and recycled concrete and geosynthetic aggregates. Aggregates are the most mined materials in the world.
Cement concrete is a cement and water paste in which aggregate particles are embedded. Aggregate usually occupies approximately 60 to 75 per cent of the volume of concrete. Besides reducing volume changes due to drying shrinkage of the cement-water paste, aggregate is inexpensive filler that reduces the cost of the concrete. Aggregate properties significantly affect the workability of plastic (concrete in the wet stage) concrete and the durability, strength, thermal properties, and density of hardened concrete. Types of rocks
Aggregates are generally sourced from natural materials or from industrial by products. Natural aggregates come from rock, of which there are three broad geological classifications. Igneous rock: These rocks are primarily crystalline and are formed by the cooling of molten rock material beneath the earth’s crust (magma).Sedimentary rocks: These rocks are formed from deposited insoluble material (e.g., the remains of existing rock deposited on the bottom of an ocean or lake). This material is transformed to rock by heat and pressure. Sedimentary rocks are layered in appearance and are further classified based on their predominant mineral as calcareous (limestone, chalk, etc.), siliceous (chert, sandstone, etc.) or argillaceous (shale, etc.).Metamorphic rock: These are igneous or sedimentary rocks that have been subjected to heat and/or pressure great enough to change their mineral structure so as to be different from the original rock.
Natural sands and gravels are the product of weathering and the action of wind or water, while stone sands and crushed stone are produced by crushing natural stone. Screening and washing may be used to process aggregates from either of these categories. Aggregates may be produced from igneous, sedimentary, or metamorphic rocks, but the presence or absence of any geological type does not, by itself, make an aggregate suitable or unsuitable for use in concrete. The acceptance of an aggregate for use in concrete on a particular job should be based upon specific information obtained from tests used to measure the aggregate quality, or upon its service record, or both. Synthetic aggregates may be either by products of an industrial process, such as blast-furnace slag, or products of processes developed to manufacture aggregates with special properties, such as expanded clay, shale or slate that are used for lightweight aggregates. Some lightweight aggregates such as pumice or scoria also occur naturally. Other classifications of aggregates may be based upon bulk density and particle shape, but these, as well as the ones previously discussed, serve mainly as aids in describing an aggregate. To understand the role played by aggregate in the performance of concrete, it is necessary to define specific aggregate properties and show their effect on concrete properties.Aggregates generally divided into two groups: Fine and Coarse aggregates.
Fine aggregates or natural or manufactured of particle size ranging from 10 mm to 0.075 mm. Coarse aggregates size ranging from 10 mm to 80 mm. The most commonly used maximum size of aggregate is 20 or 25 mm.Fine & Coarse aggregates
– IS-383 – 2016 Specification for concrete
– IS-2386 Part – I to VIII – Method of testWhy use aggregates?
We use aggregates mainly to reduce the cost of the concrete. Roughly aggregates would cost between 12 to 25 per cent of the cement price. Use of aggregate reduces thermal cracking. About 100 kg of OPC produces about 12o C temperature rise. Aggregates can reduce shrinkage, 10 percent of reduction in aggregate volume can double the shrinkage of concrete. High aggregate to cement ratio is desirable as it mainly influences cement content in concrete. Effect of aggregate size: Larger the (maximum) size; increases strength, decrease total surface area of aggregate that decreases required cement content. Improves rut resistance but increases problem with segregation of particles. Smaller maximum size can reduce segregation, reduces road noise, decreases tyre wear specially while transporting of ready mixed concrete. Why to specify sizes?
The foremost reason for specifying the size of aggregates is to control the cost of concrete, have a homogenous mix with higher bulk density, effectively use the water content and control the consumption of cement and other cementious
materials. By playing with the size of aggregates one can modify workability, pumpability, porosity and shrinkage of concrete.
Fine aggregates are nothing but the sand used in concrete. The size is down 4.75 mm to 0.075 mm and the content is usually 35 per cent to 45 per cent by mass or volume of total aggregate. Grading of aggregates: Grading is nothing but the particle-size distribution of an aggregate as determined by a sieve analysis using wire mesh sieves with square openings. As per IS:2386 (Part-1) for fine aggregate, 6 standard sieves with openings from 150 ?m to 4.75 mm. (150 ?m, 300 ?m, 600 ?m, 1.18 mm, 2.36 mm, 4.75mm) are used. For coarse aggregates , 5 sieves with openings from 4.75 mm to 80 mm. (4.75 mm, 10 mm, 12.5 mm, 20 mm, 40 mm and may be onwards). ?m is microns and 1 micron (?m) is 0.001 mm.
Grain size distribution for concrete mixes should be such that it will provide a dense strong mixture. Ensure that the voids between the larger particles are filled with medium particles. The remaining voids are filled with still smaller particles until the smallest voids are filled with a small amount of fines.
Generally in the city of Mumbai and around three type of aggregates are used which are termed as CA I( coarse aggregate),CA II and FA fine aggregates. For coarse aggregates the sizes vary from 20-25mm for CAII and 10-12 mm for CAI, the remaining third is Fine aggregate or Sand. The proportion of sand in concrete being 35 to 45 per cent, availability and price of sand has a direct impact on the production of concrete.
Fineness Modulus (FM) is a result of aggregate sieve analysis is expressed by a number called Fineness Modulus. It is obtained by adding the sum of the cumulative percentages by mass of a sample aggregate retained on each of a specified series of sieves and dividing the sum by 100. This measurement is important while designing concrete mixes with given materials at site.
Sand or fine aggregates is further graded in three categories and the following limits may be taken as guidance:Fine sand : Fineness Modulus : 2.2 – 2.6Medium sand : F.M. : 2.6 – 2.9Coarse sand : F.M. : 2.9 – 3.2
Sand having a fineness modulus more than 3.2 will be unsuitable for making satisfactory concrete.Colour of aggregates: Normally the colour of aggregates depend on the source of rock from which it is derived. The colour of aggregates that we see in Karnataka, Maharashtra and in the Northen part of India is much different. However colour has hardly any influence on the properties of concrete. But in case of decorative concretes the colour needs to satisfy the designer’s requirements. Tests on Aggregates: Fine aggregates
These are summarised as Grading, Silt & Clay content, Specific Gravity, Water absorption & moisture content, Soundness, Alkali Aggregate Reactivity, Organic Impurities and Soft Particles, Bulkage. We shall cover some of the important ones.
Impurities in fine aggregate and its effect: Clay particles, Shale, Mica, Weathered agate, Organic impurities-humus, sugar etc. These impurities lead to High water absorption, Low strength, High shrinkage, Retardation. (Slow strength gain for concrete).
Estimation of stilt content and organic impurities is very simple and can be easily carried out at site laboratory. It is recommended that every site laboratory must carry out these tests to ascertain the suitability of fine aggregates. Tests on Coarse aggregates:
– Specific gravity
– Dry Loose Bulk Density/Dry Relative Bulk Density
– Absorption & Surface moisture
– Shape
– Soundness
(Test methods – IS 2386 Part I to VIII)Tests on Coarse aggregates:
– Aggregate Crushing Value
– Aggregate Impact Value
– Aggregate Abrasion Value
– Alkali Aggregate Reactivity
(Test methods – IS 2386 Part I to VIII)Mechanical properties
Aggregate Crushing Value: Not more than 45 percent for other than wearing, surface and 30 percent for wearing surface.
Aggregate Impact Value: Not more than 45percent for other than wearing, surface and 30 percent for wearing surface.
Aggregate Abrasion Value: Not more than 50 per cent for other than wearing surface and 30 percent for wearing surface.
Aggregate Elongation & Flakiness: Not more than 40 percent (combined)
Soundness: (Loss after 5 cycles)
For fine aggregate: maximum 10 percent with sodium sulphate and 15 percent with magnesium sulphate.
For Coarse aggregate: maximum 12 percent with sodium sulphate and 18 percent with magnesium sulphate.
We thankfully acknowledge for making the articles available to us originally written by Suhas Dhuri and S Krishnan of e cube consultants, Thane and Prof. Gaurav H Tondan published on Linked in.Compilation by Vikas Damle Ex. Editor of ICR.

Concrete

JSW Cement Begins Production At Nagaur Rajasthan Plant

Greenfield integrated cement plant begins operations in Rajasthan

Published

20 hours ago

March 23, 2026

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JSW Cement has started production at a new greenfield integrated cement plant in Nagaur, Rajasthan, marking its first integrated facility in north India. The commissioning advances its national expansion and raises cement grinding capacity to 24.1 million tonnes per annum (MTPA) and clinker manufacturing capacity to nine point seven four MTPA including joint venture capacity. The plant is strategically located to serve high growth markets in Rajasthan, Haryana, Punjab and the National Capital Region.

The Nagaur plant comprises a three point three MTPA clinkerisation unit and a two point five MTPA cement grinding unit, with an additional one MTPA grinding unit under construction. The facility’s capacity additions enable it to meet regional demand and support infrastructure development. The project was funded by equity and long term debt and the company allocated Rs 8 bn from IPO proceeds to part finance the unit.

Company leadership said commissioning was completed within 21 months and that the expansion advances its aim to become a pan India player, with a mid term target of 41.85 MTPA and a long term vision of 60 MTPA. The plant includes sustainability features such as co processing of alternative fuels and a seven kilometre overland belt conveyor to transport limestone from the mines, reducing road transport impacts. The operation is expected to support economic growth and provide supplies for construction projects across the north.

The site will incorporate a 16 megawatt (MW) Waste Heat Recovery System to capture and reuse process heat, reducing the carbon footprint. JSW Cement’s operations include eight plants in India and a clinker unit in the UAE through a joint venture, providing a presence across the building materials value chain. The company emphasised use of industrial by products in manufacture and focus on producing eco friendly building materials.

Concrete

MAPEI India Celebrates 15 Years of Building Excellence

MAPEI India celebrates 15 years with growth, expansion and CSR impact

Published

20 hours ago

March 23, 2026

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MAPEI India marks its 15th anniversary, celebrating a journey defined by innovation, trust, and continuous growth. Beginning in 2011 with just four employees and a single manufacturing facility in Bengaluru, the company has evolved into a key player in India’s construction chemicals industry, now employing over 380 professionals across the country. Over the past 15 years, MAPEI India has delivered strong performance with a sales CAGR of 31 per cent. From zero production in its early years, the company shipped 1,71,000 metric tonnes of materials in 2025, demonstrating robust operational capabilities and rising market acceptance.

To support expanding demand, MAPEI India has steadily scaled its manufacturing footprint. Following the Bengaluru plant in 2011, new facilities were launched in Vadodara in 2016 and Kosi (Mathura) in 2022. A fourth facility in Kharagpur is set to go live in 2026, strengthening the company’s nationwide supply network.

As part of its commitment to global standards, MAPEI India operates under an Integrated Management System (IMS) certified for ISO 9001 (Quality), ISO 14001 (Environment) and ISO 45001 (Health & Safety). These certifications reinforce its dedication to delivering safe, sustainable, and high quality solutions.

With a diverse portfolio of over 20 product lines, MAPEI India has supported iconic projects such as the Atal Tunnel, the Statue of Unity, and major airport and metro developments. The company has also invested Rs 3.2 crore in CSR initiatives focused on education, women’s empowerment, and rehabilitation. As it steps into the future, MAPEI India remains committed to excellence, sustainability, and customer trust.

Mapei hai to bharosa hai.

Concrete

Material Flow Efficiency

Published

6 days ago

March 18, 2026

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We explore how material handling systems are becoming strategic assets in cement plants, enabling efficient movement of raw materials, clinker and finished cement. Advanced conveying, automation and digital technologies are improving plant productivity while supporting energy efficiency and sustainability goals.

Material handling systems form the operational backbone of cement plants, enabling the efficient movement of raw materials, clinker and finished cement across complex production networks. With India’s cement industry producing over 391 million tonnes of cement in FY2024 and possessing an installed capacity of around 668 mtpa, according to the CRISIL Research Industry Report, 2025, efficient material logistics have become critical to maintaining plant productivity and cost competitiveness. At the same time, cement production is highly energy intensive and contributes around 7 per cent to
8 per cent of global CO2 emissions, making efficient material flow and logistics optimisation essential for reducing operational inefficiencies and emissions states the International Energy Agency Cement Technology Roadmap, 2023. As plants scale capacity and integrate digital technologies, modern material handling systems, ranging from automated conveyors to intelligent stockyards, are increasingly recognised as strategic assets that influence plant stability, energy efficiency and environmental performance.

Strategic role of material handling
Material handling is no longer viewed as a secondary utility within cement plants; it is now recognised as a strategic system that directly influences production efficiency and process stability.
Cement manufacturing involves the continuous movement of large volumes of limestone, clay, additives, clinker and finished cement across multiple production stages. Even minor disruptions in conveying systems or storage infrastructure can lead to kiln feed fluctuations, production delays and significant financial losses. According to Indian Cement Industry Operational Benchmarking Study, 2024, unplanned downtime in large integrated cement plants can cost between Rs.15–20 lakh per hour, highlighting the economic importance of reliable material handling systems.
Modern cement plants are therefore investing in advanced mechanical handling systems designed for high throughput and operational reliability. Large integrated plants can process over 10,000 tonnes per day of clinker, requiring highly efficient conveying systems and automated stockyards to maintain continuous material flow, suggests the International Cement Review Industry Analysis, 2024. Efficient material handling also reduces spillage, minimises dust emissions and improves workplace safety. As cement plants become larger and more technologically advanced, the role of material handling is evolving from simple transport infrastructure to a critical operational system that supports both productivity and sustainability.

From quarry to plant
The transport of raw materials from quarry to processing plant represents one of the most energy-intensive stages of cement production. Traditionally, limestone and other raw materials were transported using diesel-powered trucks, which resulted in high fuel consumption, dust generation and increased operational costs. However, modern plants are increasingly adopting long-distance belt conveyors and pipe conveyors as a more efficient alternative. These systems allow continuous material transport over distances of 10–15 kilometres, significantly reducing fuel consumption and operating costs while improving environmental performance, states the FLSmidth Cement Industry Technology Report, 2024.
Milind Khangan, Marketing Manager, Vertex Market Research & Consulting, says, “Efficient and enclosed handling of fine materials such as cement, fly ash and slag requires modern pneumatic conveying systems. By optimising the air-to-material ratio, these systems can reduce energy consumption by 10 per cent to 15 per cent while ensuring smooth material flow. Closed-loop conveying further minimises dust loading and improves the performance of bag filters, supporting cleaner plant operations. In addition, flow-regulated conveying lines help prevent clogging and maintain reliable dispatch performance. Overall, automation in pneumatic conveying delivers immediate operational benefits, including improved equipment uptime, lower energy use, reduced material spillage and more stable kiln and mill performance.”
Pipe conveyor systems are particularly gaining traction because they provide a completely enclosed transport system that prevents material spillage and dust emissions. According to global cement engineering studies, conveyor-based transport can reduce energy consumption by up to 30 per cent compared to truck haulage, while also improving operational reliability. Several cement plants in India have already implemented such systems to stabilise quarry-to-plant logistics while reducing carbon emissions associated with diesel transport.

Stockyard management and homogenisation
Stockyards play a critical role in maintaining raw material consistency and stabilising kiln feed quality. Modern cement plants use advanced stacker and reclaimer systems to ensure efficient storage and blending of raw materials before they enter the grinding and pyroprocessing stages. Automated stacking methods such as chevron or windrow stacking enable uniform distribution of materials, while bridge-type or portal reclaimers ensure consistent extraction during kiln feed preparation. These systems are essential for maintaining stable chemical composition of raw meal, which directly influences kiln efficiency and clinker quality. The Cement Plant Operations Handbook, 2024 indicates that advanced homogenisation systems can reduce raw mix variability by up to 50 per cent, significantly improving kiln stability and energy efficiency. Integrated stockyard management systems also incorporate sensors for monitoring bulk density, moisture levels and stockpile volumes, enabling real-time control over material blending processes.

Clinker and cement conveying technologies
Once clinker is produced in the kiln, it must be efficiently transported to storage silos and subsequently to grinding and packing units. Modern cement plants rely on high-capacity belt conveyors, bucket elevators and pneumatic conveying systems to manage this stage of material flow. Steel-cord belt bucket elevators are now capable of lifting materials to heights exceeding 120 metres with capacities reaching 1,500 tonnes per hour, making them suitable for large-scale clinker production lines, states the European Cement Engineering Association Technical Paper, 2023.
For fine materials such as cement, fly ash and slag, pneumatic conveying systems provide a reliable and dust-free solution. These systems transport powdered materials using controlled airflow, ensuring enclosed and contamination-free movement between grinding units, silos and packing stations. Optimised pneumatic systems can reduce energy consumption by 10 per cent to 15 per cent compared to older conveying technologies, while also improving plant cleanliness and environmental compliance, according to the Global Cement Technology Review, 2024.

Automation and digitalisation
Digitalisation is transforming material handling systems by introducing real-time monitoring, predictive maintenance and automated control. Advanced sensors and Industrial Internet of Things (IIoT) platforms enable plant operators to track conveyor health, stockpile levels and equipment performance in real time. Predictive maintenance systems analyse vibration patterns, temperature fluctuations and equipment load data to detect potential failures before they occur. According to McKinsey’s Industry 4.0 Manufacturing Report, 2023, for heavy industries, digital monitoring and predictive maintenance technologies can reduce equipment downtime by up to 30 per cent and increase productivity by 10 per cent to 15 per cent. Digital control centres also integrate data from conveyors, stacker reclaimers and dispatch systems, enabling centralised management of material flows from quarry to dispatch.

Handling of AFR
The growing adoption of Alternative Fuels and Raw Materials (AFR) has introduced new challenges and opportunities for material handling systems in cement plants. AFR materials such as refuse-derived fuel (RDF), biomass and industrial waste often have irregular particle sizes, variable moisture content and lower bulk density compared to conventional fuels. As a result, specialised storage, dosing and feeding systems are required to ensure consistent kiln combustion. According to the Cement Sector Decarbonisation Roadmap published by NITI Aayog in 2026, increasing the use of AFR could enable India’s cement sector to achieve thermal substitution rates of around 20 per cent in the coming decades. To support this transition, plants are investing in automated receiving stations, shredding units, drying systems and precision dosing equipment to stabilise AFR supply and combustion performance.

Energy efficiency and dust control
Material handling systems also play a crucial role in improving plant energy efficiency and environmental performance. Modern conveyor systems equipped with variable speed drives and energy-efficient motors can significantly reduce electricity consumption. Permanent magnet motors used in conveyor drives can deliver 8 per cent to 12 per cent energy savings compared to conventional induction motors, improving overall plant energy efficiency according to the IEA Industrial Energy Efficiency Study, 2023. Dust control is another major concern in cement plants, particularly during material transfer and storage operations. Enclosed conveyors, dust extraction systems and advanced bag filters are widely used to minimise particulate emissions and improve workplace safety.

Future trends in material handling
The future of material handling in cement plants will be shaped by automation, digitalisation and sustainability considerations. Emerging technologies such as AI-driven logistics optimisation, autonomous mobile equipment and digital twins are expected to further improve plant efficiency and operational visibility. Digital twin models allow engineers to simulate material flow patterns, optimise stockyard operations and predict equipment performance under different operating conditions. According to the International Energy Agency Digitalisation and Energy Report, 2024, the adoption of advanced digital technologies could improve industrial energy efficiency by up to 20 per cent in heavy industries such as cement manufacturing. As cement plants expand capacity and adopt low-carbon technologies, intelligent material handling systems will play a critical role in maintaining productivity and reducing environmental impact.

Conclusion
Material handling systems have evolved from basic transport infrastructure into strategic operational systems that directly influence plant efficiency, reliability and sustainability. From quarry transport and automated stockyards to digital dispatch platforms and advanced conveying technologies, modern material handling solutions enable cement plants to manage large production volumes while maintaining process stability.
As India’s cement industry continues to expand to meet infrastructure and urban development demands, investments in advanced material handling technologies will become increasingly important. By integrating automation, digital monitoring and energy-efficient systems, cement manufacturers can improve operational performance while supporting the industry’s long-term sustainability and decarbonisation goals.