Concrete

Durable Concrete

Published

2 years 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

Cement Makers’ Margins To Fall Rs 50-75 Per Tonne Amid West Asia Conflict

Crisil Sees Margins Easing Despite Steady Demand

Published

2 weeks ago

July 29, 2026

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Crisil said operating margins of Indian cement manufacturers are expected to decline by Rs 50-75 per tonne (t) this fiscal to Rs 925-950 per t due to higher input costs triggered by the West Asia conflict. The analysis covered 18 cement companies accounting for nearly 90 per cent of India’s domestic cement capacity and noted margins had improved sharply to around Rs 1,000 per t in fiscal 2026.

Crisil noted that the reduction would be driven mainly by higher power and fuel costs, which account for about 30 per cent of total costs, as petcoke and imported coal prices have surged amid geopolitical uncertainties. Freight costs, which account for about a quarter of total costs, are also expected to remain elevated because of higher diesel prices. The impact on profitability is likely to be more pronounced in the first half of the fiscal year before easing commodity prices moderate cost pressures later.

The rating agency said steady domestic demand and strong balance sheets should keep credit profiles stable despite the moderation in margins. Green energy currently accounts for 35-40 per cent of the sector’s total electricity consumption and is expected to partly cushion higher energy costs. Operating cash flows are likely to remain resilient, supported by projected 6-7 per cent growth in cement demand this fiscal.

Crisil highlighted that demand growth will be driven primarily by infrastructure spending, which meets about one-third of sector consumption, and by a nearly 18 per cent higher budgetary allocation for core ministries that should support project execution. Weaker rural housing demand amid pressure on agricultural incomes from a possible below-average monsoon may be offset by improved urban housing demand supported by favourable home-loan rates and a strong pipeline of Pradhan Mantri Awas Yojana-Urban projects. Ongoing capacity additions will keep capital expenditure elevated and may lift net debt to EBITDA to between 1.2 and 1.4 times from around 1.0 time last fiscal, though ratios are expected to remain healthy.

Concrete

UltraTech Board Approves Rs 50 bn Fundraise Via NCDs

Company to issue half a million debentures for expansion plan

Published

2 weeks ago

July 28, 2026

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UltraTech Cement’s board of directors has approved raising Rs 5,000 crore (Rs 50 bn) through non?convertible debentures issued in rupees.

The finance committee cleared a proposal to issue up to 500,000 fully paid, unsecured, listed, rated, redeemable, rupee?denominated, non?convertible, non?cumulative debentures of Rs 1 lakh each (Rs 0.1 mn each), aggregating to the Rs 5,000 crore programme.

As of June 2026 the firm reported net debt of Rs 15,875 crore (Rs 158.75 bn) and said its capacity expansion projects under execution are backed by capital expenditure of about Rs 17,000 crore (Rs 170 bn) over the next two to two?and?a?half years.

UltraTech spent Rs 9,500 crore (Rs 95 bn) on capital expenditure in financial year 2026 and in April the group crossed 200.1 mn tonnes per annum of domestic grey cement capacity and 205.5 mn tonnes per annum of global capacity.

The chief financial officer indicated the company would take consolidated capacity beyond 242 mn tonnes per annum, with grey cement capacity reaching 212.7 mn tonnes per annum by the end of financial year 2027. He noted the net debt?to?earnings before interest, taxes, depreciation and amortisation ratio stood at 0.87 times as of June 2026 and the company was confident of ending financial year 2027 with the ratio below one time.

In the first quarter of financial year 2026?27 UltraTech’s net profit attributable to owners rose 16.8 per cent year?on?year to Rs 2,599.3 crore (Rs 25.993 bn) and revenue from operations increased 15.9 per cent to Rs 24,648.20 crore (Rs 246.482 bn). The board approval is expected to complement internal cash flows as the company advances its expansion programme.

Concrete

Lokesh Lays Stone For Rs 31 Billion Cement Unit In Kadapa

Line-2 expansion to make Kadapa a major cement hub

Published

3 weeks ago

July 20, 2026

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Andhra Pradesh Education and IT Minister Nara Lokesh on Wednesday laid the foundation stone for the Line-2 expansion of Dalmia Bharat Cement at Chinnakomerla village in Mylavaram Mandal in Kadapa district. The project carries an investment of Rs 31 billion (bn) and is slated for completion by the third quarter of the financial year 2028. The expansion is intended to boost industrial growth and employment generation across the Rayalaseema region.

Once commissioned, the Kadapa facility will become Dalmia Bharat’s largest integrated cement manufacturing ecosystem in southern India, creating over 1,000 direct and indirect jobs and opening new business avenues for regional micro, small and medium enterprises and transport operators. Lokesh said the expansion signalled growing corporate confidence in the state and reflected the practical ease of doing business that secured repeat investment.

He placed the project within the government’s wider economic targets and recalled the Yuvagalam padayatra commitment to generate two million (mn) jobs within five years, noting that the state would cultivate talent while industry created opportunities. Lokesh highlighted Andhra Pradesh’s competitive pursuit of major manufacturing accounts, mentioning past successes and a personal initiative to engage global investors when persuading them to anchor expansion in the state.

The plant will leverage Kadapa’s abundant limestone reserves to scale production and sustainability. Clinker capacity is planned to rise from two point five million tonnes per annum (mn tpa) to six point one mn tpa, while overall cement output will increase from three point six mn tpa to nine point six mn tpa. The unit is designed to operate on over eighty per cent renewable energy and deploy waste heat recovery, zero liquid discharge, water recycling and advanced AI systems to optimise efficiency. Industries Minister TG Bharat, BC Welfare Minister S. Savitha and Jammalamadugu MLA C. Adinarayana Reddy attended the ceremony.