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Concrete

Commonly used precast shapes

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In the olden days, wooden sleepers were used for laying the railway tracks, but due to the depleting wooden resources and increasing concern of the ecological balance, the use of concrete sleepers was started and now it has completely replaced the wooden sleepers. Concrete ties have become more common mainly due to greater economy and better support of the rails under high speed and heavy traffic. Ties are normally laid on top of track ballast, which supports and holds them in place, and provides drainage and flexibility. Heavy crushed stone is the normal material for the ballast, but on lines with lower speeds and weight, sand, gravel and even ash from the fires of coal-fired steam locomotives have been used. Regarding the market potential of the railway sleepers, their demand totally varies with the installation of new railway lines. To link almost every city and town with the other and to avoid the delay of trains because of ??ross??on single lines, number of new tracks is being installed. Tracks on high-density traffic routs with speed exceeding 100 km per hour, are being strengthened and modernised adopting improved methods of track maintenance for safer and comfortable rail travel.

Concrete sleepers can be produced from both new and recycled concrete. A railway sleeper is a rectangular support for the rails in railroad tracks. Generally laid perpendicular to the rails, ties transfer loads to the track ballast and subgrade, hold the rails upright and keep them spaced to the correct gauge. Railway sleepers are traditionally made of wood, but pre-stressed concrete is now also widely used, especially in Europe and Asia. Steel ties are common on secondary lines in the UK plastic composite ties are also employed, although far less than wood or concrete. From the view of region, Asia-Pacific and Europe have a larger sales market share in 2018 which together account for 74.02 per cent, and will witness a stable growth in following years.

The demand for sleepers will go on a lot better aspect in time to return. In the near future, the railways are probable to broaden as a minimum 5,000 to 8,000 km of rail network per year, which is almost 30 to 40 per cent extra than in past, assuming that kilometer of rail would need 1600 sleepers these plans are probable to outcomes in annual demand of about 1.3 crore of sleeper. Present manufacturing cost of monoblock broad gauge pre-stressed concrete sleeper is within the range of Rs 2,200 to Rs 2,500. The cement which is applied for the manufacture of the sleeper is the main raw material.

Cement requirement

The main requirement for railway sleepers is cement. There is a separate specification issued by Ministry of Railways through Research Design and Standards Organisation, Lucknow for the manufacture of concrete sleepers. It is popularly known as IRS T-40 grade of cement. The specification is quite similar to that of Ordinary Portland Cement 53 Grade except few parameters are different taking into account the requirement of manufacturing process of sleepers.

Likewise the cement fineness has to be minimum of 3700 sq. cm per gram. The compressive strength of cement mortar is measured only for the age of 7days and has to be minimum of 375 kg per sq cm. The tri calcium Silicate content (C3S) requirement has to be not less than 45 percent. The other requirements are same as that of 53 Grade of cement. The Indian cement industry is capable of fulfilling the entire requirement of sleeper manufacturing industry locally.

Vulnerability

The average lifespan of a pre stressed concrete sleeper is about 50 years. Over a period of time the pre stressed concrete sleepers have proved its superiority over wooden and steel sleepers. However the fundamental problems in these types of sleepers is vulnerability to chemical attack [DEF(Delayed Ettringite Formation), AAR(Alkali-Aggregate Reaction) and many others] and low impact resistance. It can be minimised by changing cement with Industrial waste cementitious materials, which will give extremely good engineering properties like protection against chemical degradation.

Railway produces around 1.3 crore (2019) sleepers each year and if they use industrial waste in concrete for sleepers, it’s going to reduce the value of manufacturing of each sleeper by approximately Rs 30, with the intention to imply a typical value saving of Rs 30 to 35 crore in keeping with annum for India Railways.

But critics have been quick to point out that the weight and bulk of concrete sleepers is a significant disadvantage when it comes to the cost ??both in time and money ??of initial installation and later repairs.

Spun pipes

The other major consumed pre cast item is spun/hume pipes. It is produced in a small scale industry (SSI) and has a very wide market. The technology used is pretty old and has not changed much but the use of these pipes is very extensive. Only SSI units can manufacture the RCC (reinforced cement concrete) pipes up to 100 cm diameter. Such pipes are classified into two groups as pressurized and non-pressurised. Cement, coarse and fine aggregate, sand, and mild and HT steel rods are used for the manufacture of such pipes. These are mostly manufactured in two lengths such as 1.8 m and 2.8 m with varying diameters from 10 cm to 100 cm. The RCC pipes are used for irrigation, culverts construction, sewerage, and drainage purposes for smooth transportation of effluents and to avoid seepage. The main raw materials used are cement, sand, aggregates, M.S. reinforcement rod and wire etc.

Manufacturing process

A mixture with raw materials such as cement, sand, and stone chips in 1:2.5:2.5 ratios are prepared with the help of power operated cement concrete mixture. Steel rod with reinforcement case is made in accordance with the dimensions of the pipe in a reinforcement making/winding machine. This case is then placed inside the pipe mold. The mold is mounted horizontally on the runners of the pipe molding machine. The mold is then rotated at a slow speed. Concrete mixture is fed into the rotating molds through its open ends at both sides.

When the mold is filled with required quantity of the mixture to obtain requisite thickness, the speed of the rotation of the mold is increased and kept at a fixed speed for few minutes depending upon the pipe diameter, length, etc. the inside diameter of the green pipe in the rotating mold is then finished for smoothness with the help of wooden reaper and to remove excess water. Thereafter neat cement is sprinkled inside the pipe to obtain a well-polished surface and to reduce friction coefficient at the time of its setting. The mold is taken out from the machine by the system and left in curing bay for the initial setting. On the following day, the molds are removed and the pipe is passed on to the curing tank and allowed to remain in the water for 15 days and then taken out for inspection and quality test. The finished product is then stocked in the yard for disposal. The pipes so manufactured are tested as per the specifications IS 458:1971 drawn by the Bureau of Indian Standards for ensuring the quality of the product.

Source: A research paper by Prof. Suresh Kumar.A and Dr.Muthukannan M. published by in International Journal of Recent Technology and Engineering (IJRTE), December 2019.

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Concrete

Cement Demand Revives As Prices Decline In Q3 FY26

Nuvama reports improved volume growth after price correction

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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.

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Concrete

Refractory demands in our kiln have changed

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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.

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Concrete

Digital supply chain visibility is critical

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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.

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