Connect with us

Concrete

Durable Concrete

Published

on

Shares

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)

Concrete

Ramco Cements Gets Andhra Pradesh Nod For Quartzite Mining

Approval covers inclusion of quartzite in Nandyal lease

Published

on

By

Shares

Ramco Cements Ltd has received approval from the Government of Andhra Pradesh to include quartzite mineral in its existing limestone mining lease in Nandyal district, the company said.

The approval allows Ramco Cements to undertake quartzite mining at Kalavataka and Kotapadu villages in Kolimigundla Mandal, Nandyal district. The company confirmed that the approval was granted on January 3, 2026.

The quantum of mineable quartzite reserves is yet to be assessed. The mineral is proposed to be used for the manufacture of manufactured sand, pozzolanic additives for the cement industry, and for other industrial applications that may be identified in the future.

According to the company, the approval will remain valid until March 10, 2053. The mining operations will be subject to compliance with all applicable terms and conditions under the Mines and Minerals (Development and Regulation) Amendment Act, 2015, along with guidelines and directions issued by the Government of India and the Government of Andhra Pradesh.

Continue Reading

Concrete

ICRA Sees Steady Cement Demand Growth Ahead

Volumes seen rising 6–7 per cent in FY27 on infra push

Published

on

By

Shares

India’s cement industry is expected to record steady growth over the coming years, with cement volumes projected to expand by 6–7 per cent in FY27, supported by sustained demand from the housing and infrastructure sectors, according to a report by rating agency ICRA.

The agency said the sector is likely to maintain healthy momentum after registering growth of 6.5–7.5 per cent in FY26, despite a higher base in the second half of FY25. Cement demand remained strong in the current financial year, with volumes increasing by 8.5 per cent during the first eight months of FY26, driven by robust construction activity across regions.

ICRA expects demand to strengthen further in the second half of FY26 as construction activity accelerates after the monsoon. Continued government focus on infrastructure spending and the possibility of a reduction in goods and services tax on cement are also expected to support demand through FY26 and FY27.

Against this favourable demand backdrop, cement manufacturers are continuing to expand capacity through both organic and inorganic routes to strengthen their market positions. The industry is estimated to add 85–90 million tonnes per annum of capacity during FY26–FY27, including around 43–45 million tonnes per annum in FY26 and a further 42–44 million tonnes per annum in FY27.

Commenting on the outlook, Anupama Reddy, Vice President and Co-Group Head, Corporate Ratings at ICRA, said sector profitability is expected to improve significantly in FY26, supported by better pricing and higher volumes. Operating profit before interest, depreciation, tax and amortisation per tonne is projected to rise to around Rs 900–950 per tonne in FY26, compared with Rs 810 per tonne in FY25.

However, ICRA expects some moderation in earnings in FY27 due to rising input costs. Operating profit per tonne is estimated at Rs 880–930 in FY27, as costs related to pet coke and freight are likely to increase and remain influenced by global crude oil prices and geopolitical developments.

On a regional basis, North and Central India are expected to report capacity utilisation levels above the national average, while the southern region may continue to see relatively moderate utilisation due to existing capacity overhang. ICRA noted that recent merger and acquisition activity in the southern market has helped large players strengthen their regional and pan-India presence.

Overall capacity utilisation for the cement industry is projected to remain stable at around 70–71 per cent in FY27, broadly in line with FY26 levels, albeit on an expanded capacity base.

Continue Reading

Concrete

GCCA India–NCB Carbon Uptake Report Released at NCB Foundation Day

New report highlights CO? absorption by concrete in Indian conditions

Published

on

By

Shares

The Global Cement and Concrete Association (GCCA) India–NCB Carbon Uptake Report was recently released during the 63rd Foundation Day celebrations of the National Council for Cement and Building Materials (NCB). On the occasion, a Gypsum Board Testing Laboratory and a Micro-Characterisation Laboratory were also inaugurated, strengthening India’s research and quality infrastructure for construction materials.

The laboratories were inaugurated by Urmila, Economic Advisor, Department for Promotion of Industry and Internal Trade (DPIIT), and Mohd. Kamal Ahmad, Special Director General, Central Public Works Department (CPWD), in the presence of L. P. Singh, Director General, NCB.

The newly established Gypsum Board Testing Laboratory will support quality assurance and standardisation requirements of the gypsum board industry, particularly in the context of the Gypsum-Based Building Materials (Quality Control) Order, 2024. The Micro-Characterisation Laboratory is equipped with advanced analytical tools for detailed investigation of cementitious and construction materials.

Addressing the gathering, Ms Urmila highlighted NCB’s sustained contributions to research, technology development, quality assurance and capacity building for the cement sector. Shri Mohd. Kamal Ahmad also commended NCB’s role in promoting sustainable construction practices through focused research and development.

The GCCA India–NCB report titled Carbon Uptake by Concrete assesses CO? uptake through carbonation in concrete under Indian conditions. Prepared in collaboration with the Global Cement and Concrete Association (GCCA) India, the study is based on the Tier-I methodology of IVL Swedish Environment Research Institute. It notes that while the cement industry contributes around seven per cent of global anthropogenic emissions, carbon uptake by concrete can partially offset process-related emissions.

The report outlines future actions to improve data robustness, refine estimation methodologies and support integration of carbon uptake into national sustainability and climate reporting frameworks. It will be submitted to the Ministry of Environment, Forest and Climate Change for consideration of inclusion as a carbon sink in India’s National Communications to the UNFCCC.

Continue Reading

Trending News

SUBSCRIBE TO THE NEWSLETTER

 

Don't miss out on valuable insights and opportunities to connect with like minded professionals.

 


    This will close in 0 seconds