India builds long-life infra, but corrosion remains a costly weak link

India is investing heavily in roads, bridges, railways, power infrastructure and telecom networks, but the economic value of these long-life assets can be eroded if they deteriorate before the end of their intended service life.

A recent Nomura report estimates that corrosion costs India about 4.3 per cent of gross domestic product (GDP), or $180 billion (about ₹14.1 trillion), a year. The report attributes the cost to the premature deterioration of infrastructure and industrial assets, higher maintenance and replacement spending and lower asset productivity. It estimates that better corrosion protection could improve India’s GDP by up to 1.5 per cent.

The issue is particularly relevant as India expands its infrastructure. The report identifies power generation and transmission as the largest contributor to the estimated corrosion burden, followed by telecommunications, automotive, infrastructure and railways. For public infrastructure, corrosion can carry costs well beyond repairs, including service disruptions and unplanned capital expenditure when facilities need rehabilitation or replacement earlier than expected.

Standards exist, but implementation gaps remain

India does not lack standards for corrosion protection. The Bureau of Indian Standards (BIS) has dedicated codes covering different materials and applications, including IS 9077:1979 for corrosion protection of steel reinforcement in reinforced concrete construction. BIS also maintains standards covering structural steel and other corrosion-protection systems.

One such standard, IS 4180:1967, covers corrosion protection of light-gauge steel sections used in buildings. It applies to cold-rolled mild-steel sections between 2 mm and 3.2 mm thick and to steel tubes used for construction, but excludes heavy structural steel work. The code sets out protection measures including surface preparation, protective coatings and painting systems to limit corrosion and environmental deterioration.

The railway system has its own detailed specifications. For example, the Research Designs and Standards Organisation’s (RDSO) 2023 standard for high-performance anti-corrosion epoxy paint specifies requirements and testing methods for paint systems intended for areas exposed to severe corrosive conditions.

The issue, therefore, is not simply whether a corrosion standard exists. It is whether protection requirements are clearly incorporated into project contracts, followed during construction and subsequently monitored and maintained.

“India’s framework remains fragmented,” Kartikey Agarwal, team lead at Centre for Law, Policy and Governance, NFPRC Foundation, told Business Standard. “India does not have a cohesive regulatory regime for corrosion. It has fragments.”

According to Agarwal, quality-control requirements can ensure that reinforcement steel and paint meet prescribed specifications when they leave the factory, but do not necessarily cover surface preparation, coating thickness and workmanship at the construction site.

The distinction is important because the durability of an asset depends not only on the material used, but also on how it is installed, protected and maintained.

Agarwal said the National Building Code, Indian Road Congress codes and RDSO specifications become requirements for a project when an asset owner incorporates them into its contract. This, he said, leaves durability largely dependent on procurement decisions rather than making it a uniform legal obligation.

When corrosion becomes a safety and maintenance cost

The consequences of corrosion can clearly be seen in official investigations and audits.

On July 3, 2018, a section of Mumbai’s Gokhale Road overbridge at Andheri collapsed onto railway tracks, killing at least two people. A preliminary report by the Commissioner of Railway Safety (CRS) found that heavy and deep corrosion and pitting of the cantilever steel brackets supporting the pathway had thinned the sections and led to their failure. It also identified additional loads from cables, sand and paver blocks as a contributing factor.

The corrosion was identified in an inspection the previous year but the bridge remained in a lower repair-priority category. Railway officials said repairs would have begun the following year.

A Comptroller and Auditor General of India (CAG) audit provides another example of deterioration translating into a direct maintenance and mobility burden. Inspecting a bridge in Maharashtra, auditors found peeled concrete, exposed and rusted reinforcement, a sagging deck and extensive spalling. A ₹35 lakh repair job was sanctioned, while another estimate of ₹62 lakh was prepared for repairs to the substructure. The bridge was closed to heavy vehicles in December 2019.

In another CAG audit in Himachal Pradesh, a prestressing cable for a bridge over Luni Khad was left in the open for years and was reported by the contractor to be badly rusted. It was used without testing. The bridge deck subsequently deflected by 10–15 cm during construction. By January 2019, government expenditure on the bridge had reached ₹76.10 lakh, while the work remained incomplete, at the time of publishing the said report.

From construction cost to lifetime cost

The cases show that the true cost of public infrastructure includes not just construction, but also maintenance, repairs and premature replacement.

A bridge that requires major rehabilitation earlier than planned, a railway asset that needs repeated coating or replacement, or infrastructure that has to be temporarily restricted because of deterioration imposes costs beyond the original construction bill.

“Durability today is a procurement choice, not a legal obligation,” Agarwal said.

He said the framework should move towards:

Service-life norms: Include a service-life statement and exposure-based durability specifications in the Model EPC Agreement.

Whole-life costing: Require state procurement to assess lifecycle costs above a specified threshold, rather than focusing only on upfront expenditure.

Durability at appraisal: Make a verified durability model part of the project-sanction process.

Agarwal also called for greater use of accredited third-party inspection, saying government agencies cannot physically inspect every bridge, girder and terminal building. Allowing contractors to certify the durability of their own work creates a conflict of interest, he added.

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