Corrosion of concrete happens due to various factors but it is necessary to repair the damage caused by such corrosion. In Part-1 of the two-part series, Upen Patel, Business Director, BASF India, dwells at length on the causes of deterioration and the remedy thereofOnce concrete repairs and strengthening was considered as an activity of rejuvenating the old structures and making them capable of loadings and environmental stresses in the future life. Today we are constructing more advanced and ever more-demanding structures with complex detailing and concrete repairs and strengthening starts during the construction stage itself. The complex and fast pace construction methods with reduced emphasis on adequate quality assurance results in to construction errors and creates needs for repairs and strengthening during construction. With the complex performance demands of the new structures and ever longer life expectancies makes concrete repairs, strengthening and protection procedures more and more demanding. This article is an attempt to present the fundamentals of concrete repairs and strengthening in a step-by-step process and focuses on the advantages and disadvantages of current practices and provides an insight in the futuristic but more simple to adopt techniques.Basic DefinitionsRepairs: To replace or correct deteriorated, damaged or faulty materials, components or elements of a concrete structure.Strengthening: The process of restoring the capacity of weakened components or elements to their original design capacity or increasing the strength of components or elements of a concrete structure.Protection: Making the structure capable to resist the likely deterioration due to the surrounding/ environment.Why concrete needs repairs?There are many factors which lead to the need of repairs such as:??Corrosion of reinforcement due to carbonation, chlorides??Sulphates??Alkali silica reaction??Environmental pollution??Deicing salts??Acid rains??Marine environment??Oils??Freeze thaw cycles??Abrasion or erosion from wind or water borne agents??Plants or microorganisms??Overloading??Physical settlement??Impact??Earthquake??Fire??Chemical attack by aggressive chemicals, sewerage or even soft waterAlso the deterioration gets aggravated due to errors/mistakes/poor workmanship during construction such as:??Higher w/c ratio??Honeycombs and compaction voids??Bleeding and segregation??Plastic shrinkages and hardening stage shrinkage cracks??Inadequate or no curing??In sufficient concrete cover??Cast-in chlorides from contaminated water/aggregates??Inadequate or excessive vibration during the concerting??Shutterwork or reinforcement movement during placement of concreteGenerally concrete structure requires repairs in the two events- New construction and during the service life. Repairs in the new construction require different approach then the repairs during service life and we shall deal one by one to better understand. The repairs during service life have more steps and we shall deal with it first. The repairs during service life arise due to certain deterioration taken place and understanding of the same is very vital in the design of the repair solution.Why concrete deteriorates?The reinforced concrete was designed with a basic understanding that its a marriage of two carrying spouses – concrete and steel. Concrete protects steel from getting corroded and steel protects concrete from getting cracked due to bending. The marriage was designed to last forever but the environment facilitates entry of many agents who leads the marriage to divorce…Major agents and their activities are described as under:-Carbonation: The high pH of concrete passivates steel reinforcement from getting corroded. The carbon dioxide / sulphur dioxide present in the atmosphere gets dissolved in the water and forms weak carbonic /sulphuric acid and enters the concrete reducing the pH, resulting in the loss of passivation layer around reinforcement. The reinforcement states getting corroded resulting in to the rust. The rust formed has 4- times the original volume of the metal creating bursting pressure in the concrete mass. The build up of the pressure eventually cracks the concrete and makes the access for ingress of corrosive water and other water dissolved agents easily. The quicker access aggravates the corrosion and structure starts deteriorating rapidly. Spalling of the concrete cover and formation of brown colored rust is a visual indication of the carbonation attack. The carbonation attack can be checked by phenolphthalein liquid. The reaction is at its best at 50-75 % relative humidity.Chloride attack: The main source of chlorides is the contaminated water or aggregates during construction and marine environment – direct contact with sea water or through wind borne chlorides in the splash zone. Chlorides ions are the passivating ferrous oxide layer on the steel reinforcement. Once reinforcement loses its passivation layer, it is highly susceptible to electro-chemical corrosion further induced by chlorides ions. The water dissolved chlorides ions form electro-chemical corrosion cell and establishes anodic and cathodic sites on the re-bar.The electro-chemical corrosion results in to pitting corrosion-reduction in the cross section of the re-bar at specific sites without noticeable deterioration of the concrete cover. The hidden reduction in the cross-section of the reinforcement can results in to sudden failure of the structure member-making this as one of the most dangerous deterioration in the concrete structure. There is no ‘net use’ of chloride ions during the corrosion process. Therefore, once enough chloride ions reach the steel to break the passivation layer only water, oxygen and a conductive medium is needed to maintain the corrosion reaction. Also note that since corrosion is a chemical reaction, temperature plays a role in the process. The higher the temperature the faster the corrosion reaction occurs. The general rule for the rate of chemical reactions is that for every 25 degree F increases, the reaction rate doubles.Sulphate attack: The main source of sulphates is the ground water. The sulphates attack on concrete, by reacting with the C3A in the concrete. The reactive product is larger in the volume resulting in to the expansive cracking in the concrete mass. The spalling and cracking of concrete takes place without any deterioration of the reinforcement to start with. With the time other forms of corrosion such as carbonation, chlorides becomes aggravated due to quicker access to the reinforcement. The sulphate attack can be reduced by using sulphate resistant cement which has low C3A content; but this reduces the resistance of chloride attack and hence no more a preferred option in the marine situation.Alkali-silica reaction (ASR): In the case of ASR the alkali-reactive aggregates forms expansive gels in the concrete structure resulting in to cracking and spalling.Step-by-step process to successful repairs:-Following steps are essential for successful repairs:-??Evaluation??Relating observations to causes??Selecting methods and material for repairs??Preparation of drawings and specifications??Selection of contractor??Execution of the work??Quality control??Preserve records for futureEvaluationEvaluate the current condition of the concrete structure. Structural analysis of the structure in its deteriorated condition, review of records of any previous repair work accomplished, review of maintenance records, visual examination, destructive and noon-destructive testing and lab analysis of concrete samples. Some of the popular tests used during the evaluation are summarised as under:-??Visual inspection and recording??Hammer sounding / Rebound hammer test??Phenolphthalein test for carbonation??Silver-nitrate test for chloride attack??Half-cell potential measurement??Core-cutting??Chemical analysis of concrete at different depthsRepair philosophyIt is most important to consider the full load envelope, which has been acting on the structure during the complete service life and in the future. The repair materials must have compatibility with the existing structure. The compatibility may be defined as a balance (equilibrium) of physical, chemical, electrochemical and dimensional properties between the repair material and the existing substrate in structural exposure conditions for a determined period of time.1st Compatibility: Physical/Permeability??Allow substrate to breath??Prevent entry of water and waterborne salts – Sulphate, Chlorides, SO2, CO2 2nd Compatibility: Chemical??No negative chemical interaction with the substrate??Absence of potentially dangerous substances such as chlorides, alkalies??No expansive ettringite formation of sulphate3rd Compatibility: Electro-chemical??Higher resistance to corrosion current??Must have conductivity and should not isolate substrate??Effective passivation of re-bars4th Compatibility: Dimensional stabilityCoefficient of Thermal Expansion: Different Coefficients of Thermal Expansion causes differential movement and hence shall be avoided.Modules of Elasticity: Under compression materials of different module will cause stress at the interface and hence shall be avoided.Drying shrinkage: Drying shrinkage of fresh mortar causes stresses at interface; hence needs to be controlled to minimum.(Extract from the paper presented by the author at the Construction Chemicals International Conference 2012 held in Mumbai)(Extract from the paper presented by the author at the Construction Chemicals International Conference 2012 held in Mumbai)
Two cement concrete pavement roads covering a total stretch of 2.2 km in Akhoya village were inaugurated on 27th June 2026 by MLA Nuklutoshi Longkumer, who attended as the special guest. The project comprises the one km L Pangersowa Road and the one point two km Longchara Junction to RC Chiten Jamir Memorial Government High School road. A formal programme followed the inauguration at the school auditorium.
A technical report was presented by Er Waloniba of the Urban Engineering Wing-III, Kohima, which stated the project was sanctioned in March 2026 under the Special Assistance to States for Capital Investment scheme for 2025-26 at a sanctioned cost of Rs 29.1 million (mn). The work order was issued to M/s Ensign Construction on thirtieth April 2026 with a stipulated completion period of 12 months. Work commenced on fourth May 2026 and was completed on sixth June 2026, with the contractor and team finishing the tasks in around two months. The project included a single-lane cement concrete pavement with side drains, two slab culverts and breast walls at required locations.
Longkumer acknowledged the Chief Minister, the advisor for urban development, contractors and other stakeholders for the allocation and support, and he commended the contractor for early completion. He noted that cooperation from landowners and the community had been important in resolving land related issues that can otherwise delay developmental works. He emphasised that planned developmental activities carried out with collective effort would enable more projects to be implemented successfully.
The headmaster of RC Chiten Jamir Memorial Government High School, I Chubasenba Longkumer, outlined the school background, noting it was established in 1962, was earlier known as Government High School Changtongya and was renamed in 2014. Local representatives said the improved approach roads would ease access for students, staff, patients and the general public and fulfil a long standing aspiration of residents. A dedicatory prayer was offered by the pastor and the programme concluded with a ribbon cutting attended by village council and town council representatives.
Indian Cement Review (ICR) and Fuller Technologies brought industry, policy and technology leaders together to discuss how cement innovation can drive green construction at scale, writes Rakesh Rao.
India is building at a pace few countries can match. Highways, airports, housing, logistics parks, industrial corridors and urban infrastructure are reshaping the country’s economic geography. But beneath this growth story lies a difficult question: can India continue to build at scale without locking itself into a high-carbon future?
That question formed the core of an online panel discussion titled “Driving Green Construction Through Cement Innovation”, organised by Indian Cement Review (ICR) in association with Fuller Technologies as the Presenting Partner on June 25, 2026. The webinar brought together experts from cement technology, R&D, global industry platforms, building performance policy and international development cooperation to examine how low-carbon cement and material innovation can accelerate India’s green construction transition.
The discussion came at a crucial time. India has committed to achieving net-zero emissions by 2070 and reducing the carbon intensity of its economy by 45 per cent by 2030. At the same time, the country’s construction sector is expanding rapidly, driven by urbanisation, infrastructure development, housing demand and industrial growth. Cement, as one of the most widely used construction materials, sits at the heart of this transition. It is indispensable to development, but also central to the challenge of reducing embodied carbon in buildings and infrastructure.
Moderated by Nitika Krishan, Senior Urban Infrastructure and Sustainable Policy Consultant, the panel featured:
Dr Hemantkumar Aiyer, VP and Head R&D, Nuvoco Vistas Corp Ltd;
Devika Wattal, Innovation Lead, Global Cement and Concrete Association (GCCA);
Dr Sunita Purushottam, MD, GBPN India (Global Buildings Performance Network); and
Vaibhav Rathi, Senior Technical Advisor, GIZ (the German Agency for International Cooperation)
Setting the tone for the discussion, Nitika Krishan underlined the scale of the challenge before the sector. “The question before us is no longer whether we build, but how we build sustainably,” she said. She pointed out that construction accounts for nearly 40 per cent of global energy-related carbon emissions when both operational and embodied carbon are considered. Cement production, she added, remains one of the hardest industrial processes to decarbonise.
For India, this is not merely an environmental issue. It is a development issue, a competitiveness issue and increasingly, a market issue. As one of the world’s largest cement producers and among the fastest-growing construction markets, India’s material choices will influence the carbon trajectory of its built environment for decades. As Krishan observed, sustainability solutions in economies such as India must not remain limited to laboratory success. They must be scalable, commercially viable and practical at national level.
The innovation gap: From technology to market
Experts believe that there is a need to bridge the innovation gaps for making decarbonisation in cement and concrete scalable. Devika Wattal of GCCA, explained, “The starting point must be the core cement manufacturing process itself. The first and foremost is the heart of our process, the heart of cement manufacturing. How do we reduce clinker? That is always a topic where industry is working very intrinsically.”
Clinker reduction remains one of the most important pathways for lowering emissions in cement. Since clinker production is energy-intensive and chemically emits carbon dioxide, reducing the clinker factor through supplementary cementitious materials (SCMs), blended cements and new chemistries can have a significant impact. Wattal also noted that carbon capture, utilisation and storage (CCUS) will have a role, though it may not be the first lever for all markets.
However, she stressed that innovation cannot stop at technology development. A solution that works in the lab must also be adaptable to industry, scalable in production and acceptable in construction practice. “It is important for that innovation to be adaptable, to be scalable, and so that it can be executed in real time,” she said.
Wattal also called for stronger enabling systems around innovation. These include performance-based standards, product-level embodied carbon databases and clearer frameworks for evaluating green materials. Without these, low-carbon cement products may struggle to compete with conventional materials in procurement and design.
R&D must balance carbon, cost and performance
Bringing in the R&D perspective into the discussion, Dr Hemantkumar Aiyer of Nuvoco Vistas emphasised that low-carbon cement development cannot be treated as a single-variable exercise. Cement must perform in real construction conditions. It must deliver strength, durability, consistency and cost competitiveness, while also reducing carbon.
“The root of understanding and balancing all these aspects lies in materials, and knowing the materials,” he said.
According to Dr Aiyer, R&D teams must understand the variability of raw materials such as fly ash, slag and clinker. Different sources produce different material behaviours. This makes mix optimisation, material characterisation and processing-property relationships critical. When performance is affected, cement manufacturers must understand how strength enhancers, admixtures and other performance chemicals interact with the material system.
He also linked material science with process efficiency. Clinkerisation takes place at extremely high temperatures, around 1,400 to 1,450 degrees Celsius. Any improvement in raw mix design, process control or energy optimisation can, therefore, help reduce emissions and cost. Dr Aiyer pointed to artificial intelligence-based optimisation, Cement 4.0 tools and advanced software as important enablers for real-time process and material control.
“The more you understand the materials, the more you can control it,” he said.
LC3: The promise is proven, the sequencing is not
Limestone calcined clay cement, commonly referred to as LC3, has attracted global attention because it can reduce clinker content significantly by using calcined clay and limestone while maintaining performance in many applications. Kiranmai Sanagavarapu of Fuller Technologies said the technology itself has already moved beyond proof of concept. Fuller Technologies has worked with calcined clay technology for nearly two decades and has seen plants running in France and Ghana. These plants, she said, are meeting local and national specifications, while the economics are beginning to make sense.
“The calciner is performing, the economics is stacking up, it is making business sense to produce,” she said.
But if the technology is viable, why has adoption not scaled faster? For Sanagavarapu, the answer lies in project sequencing. Too often, clay characterisation happens after equipment is specified. This, she warned, is a backward approach because calciner design depends on clay mineralogy, kaolinite content, iron levels, reactivity, moisture and other variables.
“If you don’t know what your deposit looks like before you commit for the equipment, you are, in a way, going blind into designing,” she said.
She also identified permitting and plant integration as major bottlenecks. Environmental clearances, mining permissions and local regulatory approvals must begin early. Similarly, calcined clay must be integrated into existing grinding, blending and logistics systems from the design stage, not treated as an afterthought during commissioning.
India already has IS 18189:2023 standard for LC3, but Sanagavarapu pointed out that the standard is not yet visible enough in procurement documents. “The gap between what is technically being permitted and what the procurement is asking is the single biggest bottleneck,” she said.
In her view, successful scale-up depends on getting the sequence right: clay characterisation first, permitting in parallel, standards aligned with construction, and integration built into plant design.
India’s LC3 journey: Progress, but demand remains thin
Providing details of India’s LC3 commercialisation experience, Vaibhav Rathi of GIZ noted that JK Cement carried out the first commercial production of LC3 at its Rajasthan plant, followed by JK Lakshmi Cement three months later. These initiatives were supported by the International Climate Initiative of the Government of Germany, with IIT Delhi contributing deep institutional knowledge on LC3 research and BIS certification.
Rathi said India’s early experience has produced clear lessons. One of the biggest was the need to build capacity among regulators. While BIS certification existed, State Pollution Control Boards were unfamiliar with the technology and unsure about the approval pathway.
“The capacity building is not just needed amongst the producer and the users of the cement, but also the regulators who are working with this technology for the first time,” he said.
He also highlighted the need for better information on China clay deposits. Since China clay is currently classified as a minor mineral, centralised data on availability, quality and location is limited. If cement manufacturers are to adopt LC3 at scale, stronger mineral intelligence will be important.
The third issue is demand. LC3 has already been used in projects such as Palava City in Mumbai and Noida International Airport, but these remain limited examples. “It is in a chicken and egg situation,” Rathi said. “Cement companies are saying we need more demand, and users are saying there is not enough cement available.”
Public procurement, he suggested, could help break this cycle. If agencies such as CPWD and other public bodies begin testing, accepting and specifying LC3, it could create the market confidence needed for cement companies to invest in production and storage.
Building codes must catch up with innovation
Dr Sunita Purushottam of GBPN India argued that material choices will determine built environment emissions over the long term, but India’s current policy signals remain fragmented. Although LC3 has received BIS recognition, she pointed out that building codes, municipal bylaws, schedules of rates and sustainability codes do not yet provide uniform guidance on low-carbon cement.
“The current cement regulations are largely prescriptive and favouring traditional materials,” she said. This limits the ability of alternative materials to compete on performance, durability and emissions.
Dr Purushottam also raised the issue of taxation. Cement, including LC3, currently falls under the same GST bracket as conventional cement. A differentiated tax structure, she argued, could help accelerate market adoption. “In order for the market to demand LC3, that differentiation in the GST could go a long way,” she said.
She noted that green building certifications such as IGBC and GRIHA are already creating demand for low-carbon materials by assigning points for embodied carbon and sustainable material use. However, she said large-scale adoption will require regulatory mandates, particularly through building codes and state-level notifications.
She also cautioned that low-carbon cement alone does not solve the entire building performance problem. A material may reduce embodied carbon, but the operational carbon of a building depends on thermal performance, design, insulation and energy use. “The energy part has two elements,” she said. “One is the embodied carbon of the material itself, and the other is the operational carbon.”
Collaboration is the bridge between invention and impact
Wattal said GCCA sees innovation as a strategic priority and works through platforms that connect industry with academia and start-ups. “There is no way we will decarbonise our sector without innovation,” she said.
However, she stressed that research must be connected to actual industry challenges. Innovations developed in isolation may fail when they encounter real-world barriers such as raw material variability, plant integration, cost, standards and finance. Start-ups, too, need industry mentorship and scale-up pathways.
Wattal also flagged the importance of finance. Even strong technologies may struggle to attract investment if there is no common understanding of bankability. “We have always put projects into, is this a bankable project? But the definition of a bankable project has never been defined,” she said.
For India, she saw strong potential in its academic and start-up ecosystem, but said the challenge lies in alignment and prioritisation. The country has the research base, industrial capacity and market size. What it now needs is a coordinated route from innovation to deployment.
There is a practical concern for cement manufacturers: how can existing plants be adapted for lower emissions without compromising reliability or commercial viability?
Kiranmai Sanagavarapu addressed, “The reliability risk in calcined clay retrofit is definitely real, but it is almost always self-inflicted. The risk arises when a new process is added to an existing circuit without properly redesigning grinding and blending configurations.”
Existing cement plants, she explained, can take two broad routes. The first is external sourcing of calcined clay combined with mill optimisation. This requires lower capital investment and can potentially move in 12 to 18 months if other conditions are in place. It may reduce emissions by around 20 to 30 per cent. The second route is integrated calcination on site, which requires higher capital expenditure and longer lead times, but provides greater control over quality, supply and emissions reduction potential.
For Sanagavarapu, the principle is simple: low-carbon retrofits must be designed with intent. “Design it with an intent properly from the start. Start in the market conditions where the economics are already working,” she said.
Circularity: The overlooked advantage
According to Vaibhav Rathi, fly ash and slag are already well established in cement and construction (C&D), but construction and demolition waste remains underutilised. “C&D waste is a growing business opportunity which not many have taken up,” he said. India’s continuous construction and demolition activity creates huge volumes of waste, much of which contributes to air pollution, land degradation and material inefficiency. With the right processing and standards, this waste can be converted into useful construction products.
Rathi also pointed out that LC3 has a circular economy dimension that is often overlooked. It can use low-grade kaolin-rich clay left behind after high-grade clay is extracted for other applications. “LC3 is not only a low-carbon solution, but also a circular economy solution,” he said.
At the same time, he cautioned that LC3 in India is not yet cheap because it has not reached scale. Site-specific techno-commercial feasibility studies, supported jointly by development agencies and industry, could help companies assess whether LC3 production makes technical and financial sense at a given location.
Dr Purushottam added that India must address both low-carbon cement and construction waste together. “Both low-carbon cement and C&D waste go hand in hand. India does not have an option but to work on both,” she said.
Dr Aiyer called for policy shifts from both government and industry, including preferential purchasing of sustainable materials, minimum supplementary cementitious material requirements in public and public-private projects, and faster regulatory implementation. “If we can fast-track the regulatory standards and their implementation on the ground, that is the way to go,” he said.
From green ambition to green construction
Cement innovation is no longer only about chemistry. It is about systems. Low-carbon cement will scale only when technology, standards, procurement, finance, regulation, education and construction practice move together.
LC3 and other low-carbon technologies have shown promise. India has early commercial examples, strong research capability and growing market interest. But mainstream adoption will depend on whether demand can be created, regulators can be capacitated, standards can be embedded in procurement, and manufacturers can see a clear business case.
For a country building at India’s scale, the opportunity is enormous. Cement will continue to be central to infrastructure and urban development. The challenge now is to ensure that the cement used in India’s growth story carries a lower carbon burden.
Rakesh Rao
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JK Cement gained after being declared preferred bidder for the Gilund Limestone Block in Chittorgarh, Rajasthan, a lease area of 370.96 hectares. The firm saw its shares trade at Rs. 5550.05, up by 28.45 points or 0.52 per cent from the previous close of Rs. 5521.60 on the BSE. The scrip opened at Rs. 5569.15 and touched a high of Rs. 5625.00 and a low of Rs. 5531.00.
The stock recorded turnover of 1742 shares on the counter and the BSE group A stock with face value Rs. 10 has a 52 week high of Rs. 7565.00 on 20-Aug-2025 and a 52 week low of Rs. 4670.05 on 12-Jun-2026. Last one week high and low stood at Rs. 5625.00 and Rs. 5329.00 respectively. The promoters holding in the company stood at 45.66 per cent, while institutions and non-institutions held 40.61 per cent and 13.73 per cent respectively.
The e-auction conducted by the Government of Rajasthan resulted in the company being declared preferred bidder for the mining lease, and the allocation will enable the company to plan phased development of the deposit, subject to regulatory approvals. The Gilund block spans 370.96 hectares and its allocation is intended to support raw material security for the company’s cement operations in the region. The designation follows the government auction process and will allow the company to plan development and integration of the deposit into its supply chain.
The current market capitalisation stands at Rs. 430.38 billion (bn), reflecting market response to the mining news and prevailing valuation levels for the sector. Investors and analysts will watch for formal allotment and related disclosures that can clarify timelines, capital expenditure and expected production profiles. The report is intended for informational purposes and does not constitute investment advice, and market participants are advised to consult advisers before making decisions.
