The National Highways Authority of India (NHAI) has begun a trial using a glass beads layer to repair identified cracks on the carriageway of the Chennai–Bengaluru Highway (NH-44), between Walajah toll gate in Ranipet and Krishnagiri. This initiative aims to enhance the durability of the 148 km stretch and prevent accidents along the route.

Currently, Larsen & Toubro maintains this highway section on behalf of NHAI under a 30-year agreement signed over a decade ago. According to regulations, a full resurfacing of the entire stretch is required once every ten years, with routine maintenance and patchwork carried out every six months.

The trial involves applying “Glass Grid Rapid” technology, developed by IIT Madras for NHAI. This entails laying a metre-wide, 0.25 mm thick roll containing small glass beads onto cracked portions of the road surface, similar to plastering. A fresh 40 mm layer of bitumen is then applied over the glass bead roll.

Work has been carried out at two locations: 1.2 km at Eraivankadu village in Vellore and 2 km at Kannigapuram village near Ambur in Tirupattur. The project is nearing completion.

NHAI officials explain that the glass bead layer acts as a strong adhesive between two bitumen layers, preventing surface cracks. This in turn helps avoid pothole formation during the monsoon, reducing waterlogging and accidents. The technology also extends the lifespan of bitumen surfaces on critical highways.

Previously, cracks were filled after milling the bitumen surface, a costly and labour-intensive process requiring removal of milled material. The glass bead method promises a more efficient and cost-effective solution.

Alongside this trial, NHAI has fully relaid the carriageway’s bitumen to a depth of 40 mm, replaced damaged steel medians, refreshed road markings including pedestrian crossings, and cleared vegetation around medians.