The city is set to rid itself of a perennial, exasperating problem — dug-up roads.
The Chennai Corporation has come up with a proposal to makeover several streets by laying them with precast, interlocking, coloured cement concrete blocks. At present, most of the city’s roads are made of bitumen, posing a number of problems for road-users. Not only do they flood during the monsoons and get severely damaged, they are constantly dug up by service agencies for various infrastructure-related work.
Since the Corporation is now unable to cope with the digging of roads and their consequent repairs, it has opted for this alternative technology, for a chunk of proposed cement roads under its jurisdiction. Several service agencies are yet to complete shifting of underground cables and utilities in many of the proposed roads. The new technology of precast interlocking blocks will make the repair of the roads considerably easier, as individual blocks can be removed and reset for underground work.
As many as 1,041 interior roads with widths ranging from 9 to 4 metres have been identified for the new makeover. The new roads will also be more aesthetically appealing, and will be durable, outlasting a standard bitumen road by two or three life cycles. The roads will last for more than 15 years, said a senior Corporation official.
The civic body has called for bids and work will be taken up in all the 15 zones of the city shortly. The project is estimated to cost Rs. 20.58 crore for 355 roads in zones 1 to 5; Rs. 19.68 crore for 342 roads in zones 6 to 10 and Rs. 22.82 crore for 344 roads in zones 11 to 15.
The road will have a base concrete of 100 mm to 150 mm thickness, and a 40 to 50 mm layer of sand cushioned beneath the interlocked precast blocks. The shape of the blocks is likely to be rectangular or hexagonal.
In accordance with the Indian Road Congress standards, the dimension of the cement blocks will be 200 mm (length) by 100 mm (width) with a thickness of 80 mm. Official say these roads will not become damaged with the difference in temperature in the day and night.
The roads will be also be maintenance-free. They are environment-friendly and, as additional stormwater storage is facilitated, runoff will be reduced considerably. “The work was not taken up in the past only because of a hesitation to try out new ideas. This technology will then be used in bus route roads if it is successful,” said a Corporation official.
