The Times of India               03.01.2014

AMC to introduce new tech for road repairs

AHMEDABAD: After drawing flak for poor roads after monsoons and reprimand from high court for poor maintenance of road quality, Ahmedabad Municipal Corporation (AMC) is in discussion to introduce two new techniques. One being introducing road micro-resurfacing machines, recently introduced in Surat and used by the National Highway Authority of India, and the other being specialized compaction meters - the size of a lawn mower - for checking road quality while it is being constructed.

In micro-resurfacing a truck-mounted machine resurfaces the road. Once repairs are done, traffic can ply within two hours after the top surface dries. While conventional road resurfacing costs Rs 350 per sq m, micro-surfacing can bring down the cost to Rs 200 per sq m. The technique uses three to six mm of bitumen aggregate which is treated with a special emulsion consisting of advanced polymers and additives. The layer is then neatly cast on the road that requires repairs.

The second instrument - the compaction meter - will check the strength and quality of a newly laid road surfaces. This way the responsibility can be immediately fixed on the contractor. The machine, when placed on the road, sends electromagnetic waves that penetrate the road surface and travel 40 mm deep and bounce back. A reading of the reflected waves would measure empty spaces between the tar and the gravel. The lesser the empty space, the stronger and denser the road and better is its quality.

The two technologies are vital as despite guarantee terms, contractors escape costly repairs as telephone companies, piped gas and electricity companies break roads to do repairs. "In the end, the AMC has to bear all expenses as the contractor claims that the guarantee terms become null and void. Till August beginning last year, if there were 176 road stretches that required repairs, the AMC ended up repairing 153 road stretches," said a senior AMC official.