The Greater Hyderabad Municipal Corporation (GHMC) is probably the first corporation in India to use white topping technology for road construction. White topping is a new technology of providing cement concrete overlay on the existing damaged and distressed bitumen roads with a purpose either to restore or to increase the load carrying capacity, or both. The newly-inducted technology by GHMC also works on the existing pavement and prevents frequent damage of roads.
GHMC has adopted this technology for two pilot projects – Road No 10 in Banjara Hills and PG Road in Secunderabad. After successful implementation of laying these roads stretches, the Government of Telangana and GHMC have formulated a proposal to carry this work over bitumen roads in several stretches in the premises. Accordingly, as many as 64 road stretches have been identified for the deployment of white topping overlay over bitumen roads in a phased manner.
According to GHMC official, white topping roads have a design life of 15-20 years. Roads designed with white topping do not require maintenance for 15 years. Meanwhile, white topping roads along with provisions of footpath, shoulders, stormwater drain with proper chamber correction and all other utilities duct are sustainable. These have long life, low-maintenance, low life cycle cost, with improved safety and environment benefits.
White topping was being used widely in the US, Europe, and some countries in Asia. The white topping layer keeps the road intact during rains, as it prevents water-logging. This technology uses fly ash and polymeric fibre, besides cement and sand, which strengthens the road surface. White topping is the covering of an existing asphalt pavement with a layer of Portland cement concrete. White topping is divided into types depending on the thickness of the concrete layer and whether the layer is bonded to the asphalt substrate.