Smoother rides this monsoon: MCD looks at 3 new technologies to plug Delhi’s infamous potholes

Senior MCD officials said the technologies being examined are Ecofix, a ready-to-use steel-slag-based pothole-repair mix; Rejupave Rejuvenator, a material for dense carpet work and resurfacing of roads; and Modified Mix Seal Surfacing or MSS+, a cold-mix surfacing technology that reduces the need to heat road material.

Officials said Ecofix, which is produced from processed steel slag, can be applied without using a tack coat, and without even draining water from the pothole. (Express photo)

The MCD maintains 12,704 lane-kilometres of roads, the largest network under any civic agency in the capital. Government sources said MCD is being provided significant road-repair funding by the Delhi government and the Centre, and it has been suggested in several high-level meetings that the civic body should follow guidelines provided by CRRI.

The three technologies

Two basic materials are used in road repairs: aggregate, or crushed stone that gives the road its structure; and binder, the bituminous material that holds the mix together. A key question in road resurfacing is how much of an old road can be reused instead of replacing it with fresh material.

CRRI’s technologies aim to fill wet potholes quickly, reuse more aggregate and binder from old road surfaces, and reduce heating during road works.

REJUPAVE REJUVENATOR: Dense carpet is a bituminous surfacing layer laid over an existing road to improve the riding surface and renew the top layer. It is usually taken up when a road has aged or developed surface distress but does not require full reconstruction.

According to CRRI, using a small quantity of Rejupave Rejuvenator — 0.5% to 1% of the dense carpet mix — can improve the reusability of aggregate and binder from the current 25% to about 60-70%.

The Municipal Corporation of Delhi (MCD) is looking for a more effective, scientifically-driven fix to the problem of potholes this year. (Express photo)

Dr Satish Pandey, Senior Principal Scientist and Head, Flexible Pavement Division, Academy of Scientific & Innovative Research (AcSIR), said the technology is significant because road relaying depends heavily on bitumen.

“Every time roads are relaid, bitumen is needed. Due to the global oil crisis, the price of imported bitumen has gone up by 2.2 to 3.3 times. In this scenario, Rejupave which maximises reutilisation of reclaimed recycled asphalt pavement (RAP) material, is important,” he said.

MSS+: Modified Mix Seal Surfacing, or MSS+, is a cold-mix method for dense carpet work. It allows binder and aggregate to be used at ambient or room temperature, unlike conventional hot-mix road work where the material has to be heated before it is laid.

Explaining the difference from conventional methods, Pandey said milling, which is the process of removing the top layer of asphalt, is done on all major roads in Delhi at 5-10 cm thickness. The road is then overlaid after the aggregate is heated at a hot-mix plant, bitumen mixes are prepared, transported to the site and compacted.

This, he said, is a time-consuming process and poses difficulties in cities such as Delhi. Conventional methods are carried out at around 150-160°C, while the developed methods require only 120-125°C, leading to a substantial reduction in greenhouse gas emissions.

Pandey said the Commission for Air Quality Management’s major focus has been dust-free road construction, and these technologies help eliminate greenhouse emissions.

ECOFIX: Ecofix is a ready-to-use material that can be placed in a damaged part of a road and compacted with a small vibrator or hand rammer. The repaired surface is ready for traffic in about 10 minutes.

In conventional pothole repair, the damaged portion has to be cleaned and dried first. Road agencies may also have to apply a tack coat, a thin bituminous layer that helps the old road surface and new repair material bind together. But these can be avoided in the new methods.

Officials said Ecofix, which is produced from processed steel slag, can be applied without using a tack coat and without draining water from the pothole. According to CRRI, Ecofix is a way to use processed metallurgical waste in road repair, reducing dependence on natural aggregates.

The Public Works Department (PWD) of the Delhi government had trialled Ecofix on Delhi Secretariat Road in April 2025. Officials had said at the time that the road could be opened to traffic immediately. However, neither patch repair using Ecofix nor dense carpeting with Rejupave has been approved yet by PWD, which maintains around 1,400 km of Delhi’s roads.

In response to why Ecofix has not been used more widely despite last year’s successful pilot, a senior PWD official said the department is focusing on strengthening longer road stretches instead of repeated patch repairs.

“This year, we have consciously moved away from the old cycle of just filling potholes again and again. Instead, we are focusing on strengthening entire stretches of roads so that the problem doesn’t come back after every monsoon,” the official said.

“We have set a target to strengthen 600 km of roads across Delhi. The effort is to fix the root cause, not just the surface. People deserve roads that last, not temporary repairs. This is a step in that direction,” the official said.

Officials said the use of Ecofix was demonstrated to MCD officials this February. A tripartite arrangement between CRRI, MCD and the vendor has been suggested for using the material on a pilot basis.

A wider relationship with CRRI

Officials said MCD is examining how CRRI’s technical expertise can be incorporated in its road works, including by providing model general conditions of contract for the works. CRRI has earlier prepared such conditions for the Karnataka government.

The civic body is also considering engaging CRRI as a third-party agency for road works above a specified value, officials said. MCD currently uses PSUs such as RITES and CEIL, and the Delhi Technological University (DTU), for quality control-related work. The New Delhi Municipal Council (NDMC) has also entered into an MoU with the institute for road-related technical work.