The Public Works Department (PWD) has to look for high performance bitumen, well-designed drainage, and quality control and design parameters as per the Indian Roads Congress (IRC) specifications and Ministry of Road Transport and Highways guidelines while relaying roads damaged in floods.
Former Chief Engineer, PWD, Joseph Mathew K. says a detailed survey of the damaged stretches must be carried out ahead of the works. “Field-level PWD engineers should visit these stretches, identify issues, and come up with separate treatment modes. Steps to check water retention are needed since the roads will get damaged again otherwise,” Mr. Mathew said. Natural flow of water should be ensured and rainwater flowing into the carriageway from households should be curbed.
Highway Act
The government can use the provisions of the Kerala Highway Protection Act for this, Mr. Mathew, also the former Project Director, KSTP, said.
With the PWD launching the initial works to repair roads using the ₹2,000 crore allotted by the government, a scientist specialising in highway engineering has called for detailed assessment of the nature and extent of the damage to prevent further washout in the northeast monsoon. The PWD’s action plan says ₹4,005.23 crore is needed for reconstruction of 34,732.45 km of road.
The highest of 964.56 km is in Kottayam followed by 844 km in Pathanamthitta, Kollam (840 km), Idukki (733 km), Thrissur (600 km), Palakkad (550 km) and 327.32 km in Wayanad. In addition, 156 km of roads, 24.78 km of retaining walls, 218 bridges, 470 culverts and drains in 297.35 km, among others, have to be reconstructed.
For damaged hilly roads, focus should be on vegetative protection, maintaining of natural slope, new technologies like soil nailing, and gabion protection, the engineer said. The foundation soil should be stabilised in the case of roads formed on weak or clay soils as in the case of Alappuzha-Changanassery Road and roads in Kuttanad. Techniques like sand columns and lime stabilisation can be adopted.
Type of bitumen
Use of natural rubber modified bitumen, crumb rubber modified bitumen and polymer modified bitumen can reduce deterioration and increase the life of the roads in the State that has two monsoons.It has been proved that roads surfaced with these bitumen provide at least 50% more service life than ordinary bitumen roads.
The PWD engineers should strictly follow MoRTH guidelines and IRC specifications for road construction in areas affected by waterlogging, flooding and or salts infestation, the scientist says.
