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Booster Dose

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Concrete is a mixture of cement and aggregates. In place of aggregates, slag can also find its use. There have been many studies carried out on slag as replacement for stone chips, and the results have been quite encouraging.

Aggregate, which makes up 70 per cent of the concrete volume, is one of the main constituent materials of concrete. Thanks to relentless construction activity, naturally occurring materials like aggregate and sand are depleting very fast. Due to the high cost of natural sand used as a fine aggregate, and the rising emphasis on sustainable construction, there is a need for the construction industry to search for alternative materials. Slag, one of the most common industrial wastes, is a by-product of steel production, and can put to such use.

One tonne of steel implies the production of 150-180 kg of slag, depending on the composition of the steel and on the steel production process. Slag often appears as granulated material containing large clusters, with coarse and very fine particles. Serious environmental problems formerly originated from uncontrolled sand and gravel taken from rivers.

The strength of concrete assumes a greater significance because the strength is related to the structure of hardened cement paste and gives an overall picture of the quality of concrete. The strength of concrete at a specific age under given curing conditions is assumed to depend mainly on the water-cement ratio and degree of compaction.

The density of concrete is lower when the natural aggregate is fully replaced by blast furnace slag aggregate. This is beneficial when lower self weight of the final product is needed.

Experiments have been conducted in laboratories to produce M30 and M20 grade concrete with good degree of quality control and mild exposure. Encouraging results in the properties of concrete were observed during partial replacement of coarse aggregate and fine aggregate by steel slag. However, it will always be a commercial decision whether to use slag in place of aggregate, because if natural materials are cheaply available, then it is not worth to try out expensive substitutes. The properties tested as a part of experimentations were compressive strength, tensile strength, flexural strength and durability.

Here were some of the observations reported:
Various experiments suggest that optimum percentage of replacement for fine aggregate is 40 per cent, and for coarse aggregate it is 30 per cent, beyond which the compressive strength decreases on further replacement.
Workability of concrete decreases as the percentage of replacement increases. Fine aggregate replacement shows better workability compared to coarse aggregate replacement.
Concrete with slag showed a much more refined pore structure than ordinary Portland cement concrete. The changes in pore structure were reflected in strength and shrinkage values.

It was also reported that the partial replacement of fine aggregate by steel slag improves the compressive tensile and flexural strength of concrete. Improvement in strength property was slightly lower for coarse aggregate (CA) replacement when compared with fine aggregate (FA) replacement. Compressive strength increased by a larger magnitude when both CA and FA were replaced by steel slag. But the flexural strength slightly decreased for combined replacement.

The weight loss in cubes after immersion in acids was very low. So, the concrete with partial replacement of CA and FA by steel slag showed better resistance to hydrochloric acid than sulphuric acid. The penetration of chloride ions in rapid chloride penetrability is low for both conventional concrete and 40 per cent fine aggregate replacement concrete. On the other hand, 30 per cent coarse aggregate replacement came under moderate penetrability.

It has also been observed that 40 per cent FA replacement performs better than 30 per cent CA replacement. Further researches can be carried out to improve the strength and acid resistance by the addition of some admixtures.

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Concrete

India donates 225t of cement for Myanmar earthquake relief

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On 23 May 2025, the Indian Navy ship UMS Myitkyina arrived at Thilawa (MITT) port carrying 225 tonnes of cement provided by the Indian government to aid post-earthquake rebuilding efforts in Myanmar. As reported by the Global Light of Myanmar, a formal handover of 4500 50kg cement bags took place that afternoon. The Yangon Region authorities managed the loading of the cement onto trucks for distribution to the earthquake-affected zones.

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Concrete

Reclamation of Used Oil for a Greener Future

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In this insightful article, KB Mathur, Founder and Director, Global Technical Services, explores how reclaiming used lubricants through advanced filtration and on-site testing can drive cost savings, enhance productivity, and support a greener industrial future. Read on to discover how oil regeneration is revolutionising sustainability in cement and core industries.

The core principle of the circular economy is to redefine the life cycle of materials and products. Unlike traditional linear models where waste from industrial production is dumped/discarded into the environment causing immense harm to the environment;the circular model seeks to keep materials literally in continuous circulation. This is achievedthrough processes cycle of reduction, regeneration, validating (testing) and reuse. Product once
validated as fit, this model ensures that products and materials are reintroduced into the production system, minimising waste. The result? Cleaner and greener manufacturing that fosters a more sustainable planet for future generations.

The current landscape of lubricants
Modern lubricants, typically derived from refined hydrocarbons, made from highly refined petroleum base stocks from crude oil. These play a critical role in maintaining the performance of machinery by reducing friction, enabling smooth operation, preventing damage and wear. However, most of these lubricants; derived from finite petroleum resources pose an environmental challenge once used and disposed of. As industries become increasingly conscious of their environmental impact, the paramount importance or focus is shifting towards reducing the carbon footprint and maximising the lifespan of lubricants; not just for environmental reasons but also to optimise operational costs.
During operations, lubricants often lose their efficacy and performance due to contamination and depletion of additives. When these oils reach their rejection limits (as they will now offer poor or bad lubrication) determined through laboratory testing, they are typically discarded contributing to environmental contamination and pollution.
But here lies an opportunity: Used lubricants can be regenerated and recharged, restoring them to their original performance level. This not only mitigates environmental pollution but also supports a circular economy by reducing waste and conserving resources.

Circular economy in lubricants
In the world of industrial machinery, lubricating oils while essential; are often misunderstood in terms of their life cycle. When oils are used in machinery, they don’t simply ‘DIE’. Instead, they become contaminated with moisture (water) and solid contaminants like dust, dirt, and wear debris. These contaminants degrade the oil’s effectiveness but do not render it completely unusable. Used lubricants can be regenerated via advanced filtration processes/systems and recharged with the use of performance enhancing additives hence restoring them. These oils are brought back to ‘As-New’ levels. This new fresher lubricating oil is formulated to carry out its specific job providing heightened lubrication and reliable performance of the assets with a view of improved machine condition. Hence, contributing to not just cost savings but leading to magnified productivity, and diminished environmental stress.

Save oil, save environment
At Global Technical Services (GTS), we specialise in the regeneration of hydraulic oils and gear oils used in plant operations. While we don’t recommend the regeneration of engine oils due to the complexity of contaminants and additives, our process ensures the continued utility of oils in other applications, offering both cost-saving and environmental benefits.

Regeneration process
Our regeneration plant employs state-of-the-art advanced contamination removal systems including fine and depth filters designed to remove dirt, wear particles, sludge, varnish, and water. Once contaminants are removed, the oil undergoes comprehensive testing to assess its physico-chemical properties and contamination levels. The test results indicate the status of the regenerated oil as compared to the fresh oil.
Depending upon the status the oil is further supplemented with high performance additives to bring it back to the desired specifications, under the guidance of an experienced lubrication technologist.
Contamination Removal ? Testing ? Additive Addition
(to be determined after testing in oil test laboratory)

The steps involved in this process are as follows:
1. Contamination removal: Using advanced filtration techniques to remove contaminants.
2. Testing: Assessing the oil’s properties to determine if it meets the required performance standards.
3. Additive addition: Based on testing results, performance-enhancing additives are added to restore the oil’s original characteristics.

On-site oil testing laboratories
The used oil from the machine passes through 5th generation fine filtration to be reclaimed as ‘New Oil’ and fit to use as per stringent industry standards.
To effectively implement circular economy principles in oil reclamation from used oil, establishing an on-site oil testing laboratory is crucial at any large plants or sites. Scientific testing methods ensure that regenerated oil meets the specifications required for optimal machine performance, making it suitable for reuse as ‘New Oil’ (within specified tolerances). Hence, it can be reused safely by reintroducing it in the machines.
The key parameters to be tested for regenerated hydraulic, gear and transmission oils (except Engine oils) include both physical and chemical characteristics of the lubricant:

  • Kinematic Viscosity
  • Flash Point
  • Total Acid Number
  • Moisture / Water Content
  • Oil Cleanliness
  • Elemental Analysis (Particulates, Additives and Contaminants)
  • Insoluble

The presence of an on-site laboratory is essential for making quick decisions; ensuring that test reports are available within 36 to 48 hours and this prevents potential mechanical issues/ failures from arising due to poor lubrication. This symbiotic and cyclic process helps not only reduce waste and conserve oil, but also contributes in achieving cost savings and playing a big role in green economy.

Conclusion
The future of industrial operations depends on sustainability, and reclaiming used lubricating oils plays a critical role in this transformation. Through 5th Generation Filtration processes, lubricants can be regenerated and restored to their original levels, contributing to both environmental preservation and economic efficiency.
What would happen if we didn’t recycle our lubricants? Let’s review the quadruple impacts as mentioned below:
1. Oil Conservation and Environmental Impact: Used lubricating oils after usage are normally burnt or sold to a vendor which can be misused leading to pollution. Regenerating oils rather than discarding prevents unnecessary waste and reduces the environmental footprint of the industry. It helps save invaluable resources, aligning with the principles of sustainability and the circular economy. All lubricating oils (except engine oils) can be regenerated and brought to the level of ‘As New Oils’.
2. Cost Reduction Impact: By extending the life of lubricants, industries can significantly cut down on operating costs associated with frequent oil changes, leading to considerable savings over time. Lubricating oils are expensive and saving of lubricants by the process of regeneration will overall be a game changer and highly economical to the core industries.
3. Timely Decisions Impact: Having an oil testing laboratory at site is of prime importance for getting test reports within 36 to 48 hours enabling quick decisions in critical matters that may
lead to complete shutdown of the invaluable asset/equipment.
4. Green Economy Impact: Oil Regeneration is a fundamental part of the green economy. Supporting industries in their efforts to reduce waste, conserve resources, and minimise pollution is ‘The Need of Our Times’.

About the author:
KB Mathur, Founder & Director, Global Technical Services, is a seasoned mechanical engineer with 56 years of experience in India’s oil industry and industrial reliability. He pioneered ‘Total Lubrication Management’ and has been serving the mining and cement sectors since 1999.

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Concrete

Charting the Green Path

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The Indian cement industry has reached a critical juncture in its sustainability journey. In a landmark move, the Ministry of Environment, Forest and Climate Change has, for the first time, announced greenhouse gas (GHG) emission intensity reduction targets for 282 entities, including 186 cement plants, under the Carbon Credit Trading Scheme, 2023. These targets, to be enforced starting FY2025-26, are aligned with India’s overarching ambition of achieving net zero emissions by 2070.
Cement manufacturing is intrinsically carbon-intensive, contributing to around 7 per cent of global GHG emissions, or approximately 3.8 billion tonnes annually. In India, the sector is responsible for 6 per cent of total emissions, underscoring its critical role in national climate mitigation strategies. This regulatory push, though long overdue, marks a significant shift towards accountability and structured decarbonisation.
However, the path to a greener cement sector is fraught with challenges—economic viability, regulatory ambiguity, and technical limitations continue to hinder the widespread adoption of sustainable alternatives. A major gap lies in the lack of a clear, India-specific definition for ‘green cement’, which is essential to establish standards and drive industry-wide transformation.
Despite these hurdles, the industry holds immense potential to emerge as a climate champion. Studies estimate that through targeted decarbonisation strategies—ranging from clinker substitution and alternative fuels to carbon capture and innovative product development—the sector could reduce emissions by 400 to 500 million metric tonnes by 2030.
Collaborations between key stakeholders and industry-wide awareness initiatives (such as Earth Day) are already fostering momentum. The responsibility now lies with producers, regulators and technology providers to fast-track innovation and investment.
The time to act is now. A sustainable cement industry is not only possible—it is imperative.

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