Concrete

Durable Concrete

Published

7 months ago

June 14, 2024

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Benefits of using ternary blend-cement, flyash and GGBFS.

Cement is the prime ingredient in concrete. One tonne of cement produces around 0.8 to 1 MT of carbon dioxide. It’s worth noting that efforts are being made to reduce the carbon footprint of cement production by using supplementary cementitious materials such as flyash and GGBS in concrete. In case of ternary blended concrete, supplementary cementitious materials flyash, GGBS are used in addition to cement, sand, aggregate, water and admixture.
To evaluate the percentage of replacement of cement with flyash and GGBS, one needs to understand the properties of concrete mixed with flyash, GGBS as ingredient, structure strength, stripping time, durability requirements.
Flyash: Pulverised coal is used in thermal power plants for electricity generation. A by-product of this combustion reaction is flyash. The electrostatic precipitators (ESPs) used inside chimneys of the power plants remove flyash before ejecting out the combustion gases into the atmosphere. Flyash is a very fine particle like residue, which has pozzolanic properties. Hence, it is often blended with cement and also used as partial replacement of cement.
Flyash consists of silica (SiO2), alumina (Al2O3) and calcium oxide (CaO) as its major components.

Due to the spherical shape of flyash, water demands in concrete are reduced and concrete becomes more cohesive.
Silica in flyash reacts with calcium hydroxide released from cement to form CSH Gel.
Formation of CSH Gel leads to increase in strength of concrete further and makes the concrete dense and durable.
35 per cent of cement can be replaced with flyash according to IS specification.
Early strength is observed to be less for flyash concrete. Due to slow development of strength of concrete, stripping time gets delayed.

Ground granulated blast furnace slag (GGBFS): Blast furnace slag is a by-product of iron ore during the iron extraction process. Amongst all mineral admixtures, blast furnace slag has the highest specific gravity (2.8 to 3.0). The slag fineness is slightly more than that of the cement.
There are various types of slag available like air cooled slag, expanded or foamed slag, granulated slag. GGBFS possesses both cementitious and pozzolanic properties. An activator is needed to hydrate the slag.

GGBFS increases the initial setting time of the concrete. But it does not alter the workability of the concrete much because its fineness is almost the same as that of the cement.
The early rate of strength gain in concrete is diminished by replacement of cement in the concrete with GGBFS.
The final strength is improved by slag cement and the durability of the concrete is increased.
Concrete uses in marine construction are highly prone to chemical attack and corrosion. GGBFS as a concrete ingredient increases resistance against sulphate and chloride attack.
Normally concrete tends to segregate with GGBS as an ingredient.

Ternary blend: Ternary blended concrete is observed to be more cohesive and workable due to presence of flyash in concrete. Early strength gain can be achieved by using both cement and GGBS in concrete. Concrete with ternary blend is a win-win situation in terms of good product quality, optimising the cost of concrete, durability and resistance against chemical attack. Additionally, the use of SCMs in concrete can contribute to sustainability efforts by minimising the cement content which is associated with significant carbon dioxide emission during its manufacturing process. The hydration process of ternary blended concrete is divided into primary reaction by OPC and GGBS, pozzolanic reaction of GGBS and flyash as the secondary process. Both materials react with Calcium hydroxide produced by cement hydration to form CSH gel which gives denser microstructure than conventional OPC concrete. The dense structure improves the durability properties of ternary blended concrete. Process yields to minimise penetration of aggressive chemicals such as sulphate, chloride as compared to conventional concrete mix.

– Nagesh Veeturi and Sumanta Sahu

(Communication by the management of the company)

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Concrete

Indian Steel Ministry Seeks $1.7 Bn for Low-Carbon Steel Production

India is actively working on a green steel policy

Published

2 days ago

January 20, 2025

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India’s Ministry of Steel has requested 150 billion rupees (approximately $1.74 billion) from the federal budget to incentivise mills to produce low-carbon steel, according to two government sources familiar with the matter.

As the world’s second-largest steel producer after China, India is actively working on a green steel policy aimed at reducing emissions in steel production. This initiative forms part of the country’s broader efforts to meet its net-zero target by 2070, as outlined by Prime Minister Narendra Modi.

The steel ministry plans to use the funds to offer incentives that encourage emissions reduction, improve research and development, increase raw material efficiency, and incentivise banks to offer lower interest rates on renewable energy loans. These details were shared by the sources, who requested anonymity as the discussions are private.

The steel ministry did not respond to an email seeking comment.

Once the funds are allocated, the ministry will submit the proposal for the cabinet’s approval. In December, the government defined ‘green steel’ as steel produced with emissions lower than 2.2 metric tons of CO2 per tonne of finished steel.

The proposed incentives would remain in place until 2030, with green steel potentially being used in government projects.

India’s steel production generates 2.55 metric tons of carbon dioxide per tonne of crude steel, 38% higher than the global average of 1.85 tons, according to Global Energy Monitor.

Concrete

Cement Industry Needs 35-45% Emissions Cut for Net-zero by 2070

This need was highlighted at a workshop organised by NITI Aayog at Vigyan Bhawan.

Published

2 days ago

January 20, 2025

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The Indian cement sector, responsible for 5.8 per cent of the country’s total CO? emissions, requires the adoption of carbon capture, utilisation, and storage (CCUS) technologies to achieve a 35-45 per cent reduction in emissions and meet the net-zero target by 2070. This need was highlighted at a workshop organized by NITI Aayog at Vigyan Bhawan.

Titled “Carbon Capture, Utilization, and Storage (CCUS) in the Indian Cement Sector,” the workshop brought together government officials, industry leaders, researchers, and academicians to discuss decarbonisation strategies. The Indian cement industry, with an installed capacity of 600 million tonnes and an annual production of 391 million tonnes, plays a critical role in the country’s infrastructure development and economy.

Prof Ajay Kumar Sood, Principal Scientific Adviser to the Prime Minister, stated that CCUS is an essential tool for addressing emissions in the cement sector, which is crucial for meeting India’s long-term climate goals. He stressed the need to balance economic growth with environmental targets and advance research and development to overcome challenges in decarbonizing this hard-to-abate sector.

Dr VK Saraswat, Member of NITI Aayog, noted that the cement industry is a key player in the Asia-Pacific region, which is witnessing rapid growth in the global cement market. He emphasised that carbon capture and utilization technologies, along with clean energy initiatives, are vital for reducing emissions in the cement sector. He also highlighted the role of carbon pricing and climate finance in supporting decarbonisation efforts.

India holds significant potential for CCUS, with regions like the Krishna-Godavari Basin, Deccan Traps, and mature oil and gas fields offering substantial CO? storage capacity. Innovative utilisation pathways, such as producing methanol, biodegradable plastics, and value-added chemicals, were discussed as potential solutions for creating a low-carbon future.

Pankaj Agarwal, Secretary of the Ministry of Power, shared that the government is preparing a comprehensive CCUS Mission to support these efforts. Ranjith Rath, CMD of Oil India, emphasised the need for innovative solutions and geo-sequestration techniques to mitigate emissions effectively.

Concrete

15th Cement EXPO: A Step Forward in Cement Innovation

Published

5 days ago

January 17, 2025

admin

Mumbai

Following the immense success of the 14th Cement EXPO, held on December 14-15, 2023, at the Manekshaw Centre, New Delhi, the next edition of this premier event is set to take place in March 2025. The 15th Cement EXPO will be hosted at Yashobhoomi, Delhi, on 12th and 13th November 2025.

Meanwhile, the Cement Expo Forum 2025 is scheduled for 5th and 6th March 2025 at Taj Krishna in Hyderabad. This exciting 3-in-1 event, organised by FIRST Construction Council (FCC) and Indian Cement Review (ICR), will bring together industry leaders, innovators, and stakeholders to discuss the future of the cement sector.

Building on the Success of the 14th Cement EXPO

The 14th Cement EXPO was widely praised for its strong participation, attracting over 1,500 senior managers and decision-makers from across the cement industry. The event was inaugurated by Dr. Vibha Dhawan, Director General of TERI, and Ali Emir Adiguzel, Founder and Director of the World Cement Association, alongside Pratap Padode, Founder of FIRST Construction Council (FCC). The two-tiered exhibition space featured cutting-edge products and innovations from top companies within the cement industry’s supply chain.

The event also garnered significant support from key government bodies, including the Ministry of Road Transport and Highways, Government e-Marketplace (GeM), and the Department for Promotion of Industry and Internal Trade (DPIIT), Ministry of Commerce and Industry, Government of India (GoI).

Recognition and Excellence in the Cement Industry

The 7th Indian Cement Review Awards celebrated excellence by presenting awards to 11 companies in various categories, recognising their contributions to growth and innovation within the industry. Notably, Parth Jindal, Managing Director of JSW Cement, was honoured with the prestigious Indian Cement Review – Person of the Year Award 2023. Meanwhile, Vinita Singhania, Vice Chairman and Managing Director of JK Lakshmi Cement Ltd, received the Lifetime Achievement Award for her outstanding leadership and contributions to the sector.

A Vision for Sustainability

With the theme of “Driving Sustainability Through Technology,” the 9th Indian Cement Review Conference hosted thought-provoking discussions and presentations, highlighting the industry’s commitment to adopting innovative, sustainable practices. The conference served as a platform for dialogue on the latest technological advancements aimed at transforming the cement sector, addressing key challenges, and fostering growth.

What to Expect from Cement EXPO 2025

The 15th Cement EXPO, along with the 10th Indian Cement Review Conference and the 8th Indian Cement Review Awards, is set to be even bigger and more impactful than the 2023 edition. With an expanded exhibition space, greater participation, and more in-depth discussions, the 2025 event will continue to drive the industry forward. This 3-in-1 event promises to be a pivotal moment in the ongoing transformation of the cement sector.

As the industry evolves, the 15th Cement EXPO 2025 will serve as a crucial platform for showcasing innovations, discussing emerging trends, and forging new partnerships to shape the future of cement and construction.

For more details:

Cement Expo Forum 2025: https://cementexpo.in/forum

15^th Cement Expo 2025: https://cementexpo.in/

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