Concrete
Measures for concrete repair and corrosion control
Published
14 years agoon
By
admin
In the first of the two-part series, Upen Patel, Business Director, BASF India, explained various factors responsible for the corrosion of concrete. In this second and last part, the author explains various components and the materials used to deal with the problem of deterioration of concrete.Once 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.Treatments of cracks:The most important criteria for selecting the right material for crack injection is based on the structural status of the crack. Is the crack alive or dormant? This can be checked by monitoring the crack width. If the crack is live, stressed are still like to relieve and hence to avoid further cracking at any other location. It is important to inject and seal the live crack with flexible injection resin such as polyurethane based. The dormant structural cracks can be sealed with epoxy/ polyurethane resins meant for structural bonding. In case if the sealing is only meant for water tightness same can be achieved by injecting with the re-swell able acrylate injection resins. The surface cracks found within the concrete covers can be open, routed and sealed used acrylic sealers as they are superficial nature but needs effective sealing as can leads to other form of corrosion/deterioration. Many hairline cracks formed on the surface of concrete cannot be opened and sealed and can be coated and sealed with high-elongation, flexible acrylic protective coatings instead.Surface preparation for volume replacementsThe surface preparation is a pre-requisite for an effective volume replacement job. Following components explains the surface preparation tasks.??Remove all identified defective concrete??Saw cut perimeters – 15mm depth??Expose steel unit no corrosion is evident??Expose the full circumference of the steel and beyond by 25mm.??Priming of the rebars: Prime immediately after cleaning. Apply a continuous coat of active zinc rich epoxy primer or appropriate corrosion protection system. Attention must be paid to the underside of the bars.??Priming of the concrete: Depending upon the need of the volume replacement materials, apply right primer. In case of chloride contaminated area use epoxy bonding agent.Cosmetic volume replacement:While replacing the concrete volume within the cover is defined as cosmetic repairs. The aim is to replace defective, deteriorated concrete cover with impervious polymer-modified mortar. The most cost effective repair materials are ready to use re-profiling mortars or to use site-batched polymer modified repair mortars with 1:5:15 proportion of polymer: cement: sand. These mortars are not capable of achieving the high compressive strengths but are able to provide effective corrosion barrier at economical costs. As the repair is within the cover zone, it does not have significant barring on the overall strength of the structure. The ready to use re-profiling mortars are shrinkage compensated and have good thixotropy enabling up to 50mm thickness built-ups in single operations; while polymer modified site batched mortars may need multi-layer applications on thick applications.Structural volume replacements:While replacing the volume of the concrete beyond concrete cover, it is very important that the member under repair is relived from the imposed loads by supports. Surface preparation is very important and any negligence may cost the success of the structural repairs. There are many options available for volume replacement such as micro concrete, single components patch repair mortars, two-component patch repair mortars, spray applied micro-concrete, site batched polymer modified mortars, self compacting concrete, shotcrete, pre-places aggregate concrete. Large volume concrete repairs can be conducted using self-compacting concrete, shotcrete or pre-placed aggregate concrete provided the interface between new and old concrete is taken care properly. Generally in India the 1st choice for volume replacement remains as form and pour micro-concrete while spray applied micro-concrete is very popular internationally due to reduced need for shuttering and ready availability of spray applied micro-concretes. Patch repair mortars if need to be used must be ready to use, one component type with fibre modification to avoid chances of cracking. Products like two-component polymer modified mortars and site-batched polymer modified mortars known for their low compressive strengths and can not be used to repair high grade concrete. In most parts of India, it’s not practical to produce site-batched polymer modified mortars with >M20 grade compressive strengths due to limitation of local fine aggregate gradation! If such low strength mortars are used to replace concrete, it leads to higher stress concentration on the rest of the structure resulting in to further distress and deterioration.Special application:Application such as under water, chemical exposures, pavement repairs, and abrasion/impact damage as well as heritage restorations requires additional considerations while repairs and now many specialized products are available for such applications some of them are summarized as below:Underwater repairs??Micro-concrete: Emaco S46UW – Anti-washout grout??Patch repair mortar: Emaco S90 – Thixotropic patching mortar??Crack injection resins: Concresive 1316 – Water insensitive resin??Re-profilinfsealing mortar – Subcote S – Resin basedChemical resistance situation??Epoxy concrete – Concresive 2929??Patch repair mortar – Concresive ERL – Epoxy liner??Re-profiling / sealing mortar – Concresive 2200 – Resin basedPavement repairs??Patch repair mortar – Emaco R650 – Rapid hardening cementitious??Re-profiling mortar – Concresive 1418T- Rapid hardening, resinousCorrosion controlWhile repairing the deteriorated structure it’s of utmost importance to prevent the rest of sound structure from getting deteriorated by implementing proper corrosion control measures. There are various options available the right selection needs to be based on the need of the situation and the practically of the options. Following is the basic introduction with the advantages and disadvantages of some of the most popular option:Film forming coatings – Acrylics and resin based coatings??Limited life expectancy (5-10 years)??Limited crack bridging limits performance on cracked substrate??No passivation of corroding reinforcementMigrated corrosion inhibitors – surface applied method??Easy to use??Effectiveness depends on chemical types and concrete porosity??Not effective against carbonation, sulphates, ASRCathodic protection – impress current method??Good life expectancy (>20 years)??Very expensive??Destructive, slow and time consuming??High application skills required??Power breakdown can disrupt the protection??No protection against carbonation, sulphate, ASR attacksCathodic protection – Impress current method??Low to medium life expectancy (5 – 10 years)??Destructive method, requires replacements in future??Lump-sum application, design guidelines not followed??Not practical in heavy reinforced members??Corrosion continues; instead of steel embedded zinc corrodes??Not effective against carbonation, sulphates, ASR.Protectosil CIT – Organo-functional silane based system??Spray applied – easy to use??Organo functional silane based – deep penetrative??Monomer structure – chemically reacts, no degradation in UV??Corrosion inhibition effect – repassivates rebar??Effective in all four types of corrosion as it hydrophobize concrete??Well-established and tested worldwide??Non destructive method??Measurable reduction of corrosion current??Effective till treated concrete thickness lasts!Other important aspects of repairsWhile right diagnosis and selection of materials is the core of the repair project; other aspects such as preparation of drawings and specifications, selection of right contractor, execution of the work to the specifications, adequate quality control are equally important. Repair project is more specialised and good site management and construction practices have to be followed. Also at the end of the job all the records relating to the diagnosis, material selection and execution of the work shall be maintained and preserved for any reference needs in future.Conclusion:With the right focus on the causes, evaluation and selection of correct repair materials; the resultant repairs would be long lasting and we would be able to avoid expensive repetitions of repairs in the future.(Extract from the paper presented by the author at the Construction Chemicals International Conference 2012 held in Mumbai)
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Concrete
Cement Demand Revives As Prices Decline In Q3 FY26
Nuvama reports improved volume growth after price correction
Published
17 hours agoon
February 24, 2026By
admin
A report by Nuvama Financial Services (Nuvama) said cement sector demand revived in the third quarter of fiscal year twenty twenty six as prices declined, supporting volume growth across regions. The note indicated that sequential price correction helped replenish demand that had been subdued by elevated pricing earlier in the year. Nuvama quantified the price decline as a sequential correction that varied across states and segments, facilitating restocking by merchants and traders.
The report suggested that improved affordability after the price correction encouraged housing and infrastructure activity, with developers and contractors adjusting procurement plans. It added that regional dynamics varied, with some markets showing faster recovery while others remained reliant on seasonal construction cycles. Housing demand was driven by both affordable and mid segment projects, while infrastructure segment recovery was contingent on timely execution of public works.
Analysts at Nuvama assessed that the price moderation eased inventory pressures for manufacturers and distributors and supported margin stabilisation at several producers. Demand improvement was visible in both urban and rural segments, although the pace of recovery differed by state and trade channel. Producers were seen balancing price realisations with volume targets and managing input cost volatility through operational efficiencies.
The report recommended that investors monitor volumes and realisations closely as market equilibrium emerges in the coming quarters, noting that sustainability of recovery would depend on monsoon patterns and government infrastructure outlays. Overall, the assessment pointed to a cautiously optimistic outlook for the cement industry as price correction translated into tangible volume gains. Market participants were advised to track early signs of demand broadening beyond core construction hubs to assess the depth of the rebound.
Concrete
Refractory demands in our kiln have changed
Published
5 days agoon
February 20, 2026By
admin
Radha Singh, Senior Manager (P&Q), Shree Digvijay Cement, points out why performance, predictability and life-cycle value now matter more than routine replacement in cement kilns.
As Indian cement plants push for higher throughput, increased alternative fuel usage and tighter shutdown cycles, refractory performance in kilns and pyro-processing systems is under growing pressure. In this interview, Radha Singh, Senior Manager (P&Q), Shree Digvijay Cement, shares how refractory demands have evolved on the ground and how smarter digital monitoring is improving kiln stability, uptime and clinker quality.
How have refractory demands changed in your kiln and pyro-processing line over the last five years?
Over the last five years, refractory demands in our kiln and pyro line have changed. Earlier, the focus was mostly on standard grades and routine shutdown-based replacement. But now, because of higher production loads, more alternative fuels and raw materials (AFR) usage and greater temperature variation, the expectation from refractory has increased.
In our own case, the current kiln refractory has already completed around 1.5 years, which itself shows how much more we now rely on materials that can handle thermal shock, alkali attack and coating fluctuations. We have moved towards more stable, high-performance linings so that we don’t have to enter the kiln frequently for repairs.
Overall, the shift has been from just ‘installation and run’ to selecting refractories that give longer life, better coating behaviour and more predictable performance under tougher operating conditions.
What are the biggest refractory challenges in the preheater, calciner and cooler zones?
• Preheater: Coating instability, chloride/sulphur cycles and brick erosion.
• Calciner: AFR firing, thermal shock and alkali infiltration.
• Cooler: Severe abrasion, red-river formation and mechanical stress on linings.
Overall, the biggest challenge is maintaining lining stability under highly variable operating conditions.
How do you evaluate and select refractory partners for long-term performance?
In real plant conditions, we don’t select a refractory partner just by looking at price. First, we see their past performance in similar kilns and whether their material has actually survived our operating conditions. We also check how strong their technical support is during shutdowns, because installation quality matters as much as the material itself.
Another key point is how quickly they respond during breakdowns or hot spots. A good partner should be available on short notice. We also look at their failure analysis capability, whether they can explain why a lining failed and suggest improvements.
On top of this, we review the life they delivered in the last few campaigns, their supply reliability and their willingness to offer plant-specific custom solutions instead of generic grades. Only a partner who supports us throughout the life cycle, which includes selection, installation, monitoring and post-failure analysis, fits our long-term requirement.
Can you share a recent example where better refractory selection improved uptime or clinker quality?
Recently, we upgraded to a high-abrasion basic brick at the kiln outlet. Earlier we had frequent chipping and coating loss. With the new lining, thermal stability improved and the coating became much more stable. As a result, our shutdown interval increased and clinker quality remained more consistent. It had a direct impact on our uptime.
How is increased AFR use affecting refractory behaviour?
Increased AFR use is definitely putting more stress on the refractory. The biggest issue we see daily is the rise in chlorine, alkalis and volatiles, which directly attack the lining, especially in the calciner and kiln inlet. AFR firing is also not as stable as conventional fuel, so we face frequent temperature fluctuations, which cause more thermal shock and small cracks in the lining.
Another real problem is coating instability. Some days the coating builds too fast, other days it suddenly drops, and both conditions impact refractory life. We also notice more dust circulation and buildup inside the calciner whenever the AFR mix changes, which again increases erosion.
Because of these practical issues, we have started relying more on alkali-resistant, low-porosity and better thermal shock–resistant materials to handle the additional stress coming from AFR.
What role does digital monitoring or thermal profiling play in your refractory strategy?
Digital tools like kiln shell scanners, IR imaging and thermal profiling help us detect weakening areas much earlier. This reduces unplanned shutdowns, helps identify hotspots accurately and allows us to replace only the critical sections. Overall, our maintenance has shifted from reactive to predictive, improving lining life significantly.
How do you balance cost, durability and installation speed during refractory shutdowns?
We focus on three points:
• Material quality that suits our thermal profile and chemistry.
• Installation speed, in fast turnarounds, we prefer monolithic.
• Life-cycle cost—the cheapest material is not the most economical. We look at durability, future downtime and total cost of ownership.
This balance ensures reliable performance without unnecessary expenditure.
What refractory or pyro-processing innovations could transform Indian cement operations?
Some promising developments include:
• High-performance, low-porosity and nano-bonded refractories
• Precast modular linings to drastically reduce shutdown time
• AI-driven kiln thermal analytics
• Advanced coating management solutions
• More AFR-compatible refractory mixes
These innovations can significantly improve kiln stability, efficiency and maintenance planning across the industry.
Concrete
Digital supply chain visibility is critical
Published
5 days agoon
February 20, 2026By
admin
MSR Kali Prasad, Chief Digital and Information Officer, Shree Cement, discusses how data, discipline and scale are turning Industry 4.0 into everyday business reality.
Over the past five years, digitalisation in Indian cement manufacturing has moved decisively beyond experimentation. Today, it is a strategic lever for cost control, operational resilience and sustainability. In this interview, MSR Kali Prasad, Chief Digital and Information Officer, Shree Cement, explains how integrated digital foundations, advanced analytics and real-time visibility are helping deliver measurable business outcomes.
How has digitalisation moved from pilot projects to core strategy in Indian cement manufacturing over the past five years?
Digitalisation in Indian cement has evolved from isolated pilot initiatives into a core business strategy because outcomes are now measurable, repeatable and scalable. The key shift has been the move away from standalone solutions toward an integrated digital foundation built on standardised processes, governed data and enterprise platforms that can be deployed consistently across plants and functions.
At Shree Cement, this transition has been very pragmatic. The early phase focused on visibility through dashboards, reporting, and digitisation of critical workflows. Over time, this has progressed into enterprise-level analytics and decision support across manufacturing and the supply chain,
with clear outcomes in cost optimisation, margin protection and revenue improvement through enhanced customer experience.
Equally important, digital is no longer the responsibility of a single function. It is embedded into day-to-day operations across planning, production, maintenance, despatch and customer servicing, supported by enterprise systems, Industrial Internet of Things (IIoT) data platforms, and a structured approach to change management.
Which digital interventions are delivering the highest ROI across mining, production and logistics today?
In a capital- and cost-intensive sector like cement, the highest returns come from digital interventions that directly reduce unit costs or unlock latent capacity without significant capex.
Supply chain and planning (advanced analytics): Tools for demand forecasting, S&OP, network optimisation and scheduling deliver strong returns by lowering logistics costs, improving service levels, and aligning production with demand in a fragmented and regionally diverse market.
Mining (fleet and productivity analytics): Data-led mine planning, fleet analytics, despatch discipline, and idle-time reduction improve fuel efficiency and equipment utilisation, generating meaningful savings in a cost-heavy operation.
Manufacturing (APC and process analytics): Advanced Process Control, mill optimisation, and variability reduction improve thermal and electrical efficiency, stabilise quality and reduce rework and unplanned stoppages.
Customer experience and revenue enablement (digital platforms): Dealer and retailer apps, order visibility and digitally enabled technical services improve ease of doing business and responsiveness. We are also empowering channel partners with transparent, real-time information on schemes, including eligibility, utilisation status and actionable recommendations, which improves channel satisfaction and market execution while supporting revenue growth.
Overall, while Artificial Intelligence (AI) and IIoT are powerful enablers, it is advanced analytics anchored in strong processes that typically delivers the fastest and most reliable ROI.
How is real-time data helping plants shift from reactive maintenance to predictive and prescriptive operations?
Real-time and near real-time data is driving a more proactive and disciplined maintenance culture, beginning with visibility and progressively moving toward prediction and prescription.
At Shree Cement, we have implemented a robust SAP Plant Maintenance framework to standardise maintenance workflows. This is complemented by IIoT-driven condition monitoring, ensuring consistent capture of equipment health indicators such as vibration, temperature, load, operating patterns and alarms.
Real-time visibility enables early detection of abnormal conditions, allowing teams to intervene before failures occur. As data quality improves and failure histories become structured, predictive models can anticipate likely failure modes and recommend timely interventions, improving MTBF and reducing downtime. Over time, these insights will evolve into prescriptive actions, including spares readiness, maintenance scheduling, and operating parameter adjustments, enabling reliability optimisation with minimal disruption.
A critical success factor is adoption. Predictive insights deliver value only when they are embedded into daily workflows, roles and accountability structures. Without this, they remain insights without action.
In a cost-sensitive market like India, how do cement companies balance digital investment with price competitiveness?
In India’s intensely competitive cement market, digital investments must be tightly linked to tangible business outcomes, particularly cost reduction, service improvement, and faster decision-making.
This balance is achieved by prioritising high-impact use cases such as planning efficiency, logistics optimisation, asset reliability, and process stability, all of which typically deliver quick payback. Equally important is building scalable and governed digital foundations that reduce the marginal cost of rolling out new use cases across plants.
Digitally enabled order management, live despatch visibility, and channel partner platforms also improve customer centricity while controlling cost-to-serve, allowing service levels to improve without proportionate increases in headcount or overheads.
In essence, the most effective digital investments do not add cost. They protect margins by reducing variability, improving planning accuracy, and strengthening execution discipline.
How is digitalisation enabling measurable reductions in energy consumption, emissions, and overall carbon footprint?
Digitalisation plays a pivotal role in improving energy efficiency, reducing emissions and lowering overall carbon intensity.
Real-time monitoring and analytics enable near real-time tracking of energy consumption and critical operating parameters, allowing inefficiencies to be identified quickly and corrective actions to be implemented. Centralised data consolidation across plants enables benchmarking, accelerates best-practice adoption, and drives consistent improvements in energy performance.
Improved asset reliability through predictive maintenance reduces unplanned downtime and process instability, directly lowering energy losses. Digital platforms also support more effective planning and control of renewable energy sources and waste heat recovery systems, reducing dependence on fossil fuels.
Most importantly, digitalisation enables sustainability progress to be tracked with greater accuracy and consistency, supporting long-term ESG commitments.
What role does digital supply chain visibility play in managing demand volatility and regional market dynamics in India?
Digital supply chain visibility is critical in India, where demand is highly regional, seasonality is pronounced, and logistics constraints can shift rapidly.
At Shree Cement, planning operates across multiple horizons. Annual planning focuses on capacity, network footprint and medium-term demand. Monthly S&OP aligns demand, production and logistics, while daily scheduling drives execution-level decisions on despatch, sourcing and prioritisation.
As digital maturity increases, this structure is being augmented by central command-and-control capabilities that manage exceptions such as plant constraints, demand spikes, route disruptions and order prioritisation. Planning is also shifting from aggregated averages to granular, cost-to-serve and exception-based decision-making, improving responsiveness, lowering logistics costs and strengthening service reliability.
How prepared is the current workforce for Industry 4.0, and what reskilling strategies are proving most effective?
Workforce preparedness for Industry 4.0 is improving, though the primary challenge lies in scaling capabilities consistently across diverse roles.
The most effective approach is to define capability requirements by role and tailor enablement accordingly. Senior leadership focuses on digital literacy for governance, investment prioritisation, and value tracking. Middle management is enabled to use analytics for execution discipline and adoption. Frontline sales and service teams benefit from
mobile-first tools and KPI-driven workflows, while shop-floor and plant teams focus on data-driven operations, APC usage, maintenance discipline, safety and quality routines.
Personalised, role-based learning paths, supported by on-ground champions and a clear articulation of practical benefits, drive adoption far more effectively than generic training programmes.
Which emerging digital technologies will fundamentally reshape cement manufacturing in the next decade?
AI and GenAI are expected to have the most significant impact, particularly when combined with connected operations and disciplined processes.
Key technologies likely to reshape the sector include GenAI and agentic AI for faster root-cause analysis, knowledge access, and standardisation of best practices; industrial foundation models that learn patterns across large sensor datasets; digital twins that allow simulation of process changes before implementation; and increasingly autonomous control systems that integrate sensors, AI, and APC to maintain stability with minimal manual intervention.
Over time, this will enable more centralised monitoring and management of plant operations, supported by strong processes, training and capability-building.
Cement Demand Revives As Prices Decline In Q3 FY26
Refractory demands in our kiln have changed
Digital supply chain visibility is critical
Redefining Efficiency with Digitalisation
Cement Additives for Improved Grinding Efficiency
Cement Demand Revives As Prices Decline In Q3 FY26
Refractory demands in our kiln have changed
Digital supply chain visibility is critical
Redefining Efficiency with Digitalisation
Cement Additives for Improved Grinding Efficiency
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