Concrete

Making Concrete in Cold Conditions

Published

10 years ago

February 28, 2017

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Cold weather is defined as a period when the average daily temperature falls below 4?C for more than three successive days. These conditions warrant special precautions when placing, finishing, curing and protecting concrete.

Concrete production always faces a problem during cold weather. There are two main problems associated with cold weather. The general rule is that the concrete has to gain strength till about 500 psi (35 kg per cm2).

Concrete can freeze before it gains strength which breaks up the matrix;
Concrete sets more slowly when it is cold – very slow below 6? C; below 4? C, the hydration reaction basically stops and the concrete doesn’t gain strength.
But these are concrete temperatures, not air temperatures. So when it’s cold, the concrete has to be protected until it can handle the cold on its own. The general rule is that the concrete has to gain strength till about 500 psi (35 kg per cm2). Almost the same time that the concrete achieves 500 psi compressive strength, hydration of the cement consumes enough of the water in the original mix so that even if it does freeze, there’s not enough water left in the pores to damage the concrete. With most concrete, even at 6?C, this happens during the second day.

To help it reach that 500 psi strength, the mix can then be changed to get it to set more quickly or protect the concrete from the cold – or more likely do both.

Changes to Concrete Mix during Cold Weather
Many of the problems with cold weather can be overcome by the ready mix producer. Here are a few things to keep in mind:
Hot water: A ready mixed concrete producer will usually have, and use, hot water in the concrete when the weather turns cold. Most producers will try to have the concrete be at least 180C when it leaves the plant, which is generally good enough depending on air temperature and thickness of the concrete element. The slump has to be specified at less than 100 mm and air-entrained concrete should be used to reduce bleeding.

Accelerators: Since colder weather leads to colder concrete, the set time can be delayed. Accelerators added to the concrete can keep it on schedule. Addition of 2 per cent (by weight of cement) of calcium chloride is the traditional way to accelerate the hydration reaction – it is very effective and reasonably cheap. But – a big but -that much chloride can lead to corrosion of any steel embedded in the concrete (like rebar) and can lead to a mottled surface appearance with coloured concrete.

Non-chloride accelerators are also widely available and are very effective. They won’t discolour the concrete, but they are a bit expensive. Accelerators are not anti-freeze agents – they simply increase the rate of the hydration reaction.

Fly ash: Producers should typically stay away from using fly ash or slag cement in cold weather, since those materials set more slowly and generate less internal heat; slag can cause the same effect.

To make the reaction a bit hotter, the ready mix producer can add some extra cement (typically 60 kg per cubic metre) or can use Type III (high-early strength) cement, which hydrates more rapidly.

Producers have to be careful with water reducers in cold weather, since they can slow the set time. Besides, cooler concrete seldom needs water reduction since the cooler temperatures prevent slump loss. For admixtures added at the job site, they shouldn’t be used if they have frozen. The chemicals may have separated.

Precautions before Placing Concrete in the Cold
When cold weather comes on unexpectedly, the following tips will help:
Frozen ground: Concrete should be never placed on frozen ground or onto ice or snow. There are a couple of problems with this. First, frozen ground will settle when it thaws, cracking the concrete. Second, when the ground is cold, the concrete in contact with it will be cold and will set more slowly. Crusting might also occur, with the top part of the concrete set and the bottom still soft. If the ground is frozen, it can be thawed using hydronic heat pipes and blankets (such as those from ground heaters), or electric blankets.

Anything that will come in contact with the concrete should be warmed up, including forms and any embedment, to at least 00C. If it’s not too cold and everything is covered with tarps the day before the pour, it will stay dry and warm enough.

Concrete

Andhra Pradesh Clears Rs. 30 bn My Home Cement Plant

Project receives incentives of up to Rs. 11.29 bn from state

Published

8 hours ago

September 30, 2026

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The Andhra Pradesh government has approved a greenfield cement project worth Rs. 30 bn by My Home Industries, along with incentives of up to Rs. 11.29 bn. The decision comes amid a political controversy in Telangana involving allegations about landholdings associated with My Home Group.

According to an Industries and Commerce Department order issued on September 25, 2026, the project is expected to create 2,000 jobs and begin commercial production by March 2029. The proposed facility will have capacity to produce 3.5 MTPA of clinker and 3.5 MTPA of cement.

The total investment includes fixed capital investment of Rs. 25.97 bn, pre-operative expenses of Rs. 2.23 bn, contingencies of Rs. 1.26 bn and working capital margin of Rs. 540 mn. The incentive package is capped at Rs. 11.29 bn, equivalent to up to 43.48 per cent of fixed capital investment, subject to completion of the committed investment by March 2029.

The package includes a capital subsidy of 39 per cent of eligible fixed capital investment, capped at Rs. 9.43 bn, payable over 10 years from the start of commercial production. It also provides reimbursement of Rs. 1 per unit on electricity purchased from distribution companies for 10 years, subject to a ceiling of Rs. 1.86 bn. A further incentive equivalent to 2 per cent of fixed capital investment is linked to the creation of the committed jobs and other policy conditions.

The state has approved the allotment of 27.19 acres through the Andhra Pradesh Industrial Infrastructure Corporation at actual cost. The project also involves land linked to two temples and the realignment of a canal across approximately 9.93 acres, with conditions requiring alternative temple facilities and company-funded infrastructure work. Telangana Chief Minister A. Revanth Reddy has separately raised allegations concerning land associated with My Home Group, including 2,463 acres near Shamshabad. The allegations remain subject to verification through official records and any investigations.

Concrete

Nuvoco Vistas, CleanMax Partner for Wind-Solar Hybrid Project in Rajasthan

Published

1 day ago

September 29, 2026

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The project – comprising 20 MW of wind and 26.4 MWdc of solar capacity – will support Nuvoco’s cement operations with cleaner power while strengthening its renewable energy and decarbonisation strategy.

Mumbai, September 29, 2026

Nuvoco Vistas Corp Ltd, part of Nirma Group and one of India’s leading cement companies, has partnered with Clean Max Enviro Energy Solutions Limited (CleanMax), a renewable energy solutions provider for the commercial and industrial (C&I) sector, to develop a 46.4 MW wind-solar hybrid renewable energy project in Rajasthan.

The project will support Nuvoco’s cement operations with cleaner power while strengthening its renewable energy and decarbonisation strategy. It is expected to increase the share of renewable energy in Nuvoco’s power mix, reducing fossil fuel consumption and associated emissions.

Developed by CleanMax, an Independent Power Producer (IPP), at Bhikamkhore, Rajasthan, the project will comprise 20 MW of wind capacity and 26.4 MWdc of solar capacity, along with a 2-MWh Battery Energy Storage System (BESS). Power generated from the facility will be supplied to Nuvoco through the State Transmission Utility (STU) Open Access network.

The hybrid project is expected to generate approximately 100 million units (MU) of renewable electricity annually and help avoid around 1,25,485 tonnes of CO₂ emissions every year across Scope 1 and Scope 2 emissions.

The initiative supports Nuvoco’s ongoing efforts to reduce the carbon intensity of its manufacturing operations through renewable energy adoption, Waste Heat Recovery Systems (WHRS), energy-efficiency measures and increased use of alternative fuels. It also aligns with the company’s DIRE (Digitalisation, Innovation and Renewables) agenda, which focuses on climate action, renewable energy transition, water stewardship, circularity and biodiversity conservation across its manufacturing ecosystem.

Commenting on the initiative, Jayakumar Krishnaswamy, Managing Director, Nuvoco Vistas Corp Ltd, said, “This marks an important step in advancing Nuvoco’s journey towards more sustainable and resilient operations. Our collaboration with CleanMax will increase the share of renewable energy across our Rajasthan operations, strengthening our energy mix while improving long-term cost efficiency and reducing our dependence on conventional power sources. Initiatives such as these reinforce our commitment to operational excellence and responsible growth, while supporting our vision of Building a Safer, Smarter and Sustainable World.”

Kuldeep Jain, Founder and Managing Director, CleanMax, said, “Cement plants run continuously, so the power behind them has to be dependable for decades, not years. We’re seeing manufacturing industries view clean energy as an integral part of their core operations and long-term strategy. Our partnership with Nuvoco reflects that shift, and we’re pleased to support its decarbonisation journey. This wind-solar hybrid project is designed to deliver long-term cost certainty while supporting the Company’s transition to cleaner power.”

Nuvoco has been advancing its sustainability initiatives through renewable energy, operational efficiency and technology-driven solutions. The company operates across Cement, Ready-Mix Concrete (RMX) and Modern Building Materials (MBM) segments, with a presence across East, North and West India.

The company began operations in 2014 with a greenfield cement plant in Nimbol, Rajasthan, and later acquired Lafarge India Limited, which entered India in 1999, along with Emami Cement Ltd in 2020 and Vadraj Cement Limited in April 2025. With planned expansion initiatives, including a new grinding mill at the Arasmeta Cement Plant and multiple debottlenecking projects, Nuvoco aims to achieve a cement capacity of 35 MMTPA.

The company reported total income of Rs 113.62 billion in FY 2025-26, reflecting its continued growth trajectory. Its cement portfolio includes Concreto, Duraguard, Double Bull, PSC, Nirmax and Infracem brands, while its RMX business offers products under Concreto, Artiste, InstaMix, X-Con and Ecodure brands. Nuvoco also provides construction solutions under its Zero M range of modern building materials.

Concrete

UltraTech Unit Runs Entirely on Green Energy

Kukurdih Cement Works meets its full electricity needs through green energy.

Published

1 day ago

September 29, 2026

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UltraTech Cement has achieved a decarbonisation milestone, with its integrated Kukurdih Cement Works in Chhattisgarh meeting 100 per cent of its electricity requirement through green energy every month since April 2026.

Commissioned in 2024, the plant has an installed grey cement capacity of 3.3 million tonnes per annum. It meets its entire electricity requirement through a combination of renewable power sourcing and Waste Heat Recovery Systems (WHRS), while maintaining operational reliability.

Since April 2026, nearly a third of UltraTech’s 76 manufacturing units in India have maintained green energy utilisation above 50 per cent of their electricity requirements. Five units, including Kukurdih Cement Works, have exceeded 95 per cent green energy utilisation.

UltraTech is also progressively deploying Battery Energy Storage Systems (BESS) across its manufacturing network to enable deeper integration of renewable energy. The company has not invested in new captive thermal power capacity for greenfield projects or brownfield expansions at its integrated units for more than a decade.

As of Q1FY27, UltraTech’s captive green energy capacity stood at 1,897 MW, comprising 1,463 MW of renewable capacity across solar, wind and hybrid sources, and 434 MW of WHRS capacity.

Under its RE100 commitment, UltraTech aims to increase green power’s share in its total power mix to 85 per cent by 2030 and 100 per cent by 2050.