All of these roads are constructed using cement concrete for long life without sacrificing on quality in construction and supervision.
— Prof. M. N. Sreehari, Road Infrastructure Expert, Adviser & Consultant
Prof Sreehari wrote about the city of Bengaluru, ಬೆಂಗಳೂರು, in Karnataka, India, as well as other cities, in a January 2022 issue of The New Indian Express online magazine. He said that while Chief Minister Basavaraj Bommai had set a deadline of January 15, 2022 to have all potholes filled, there are some important points that needed to be stressed—not just to fill potholes, but to ensure that potholes do not recur! If authorities work to ensure quality roads without potholes, cracks or ruts, and want to make it convenient for motorists to use them, it will require a little application of mind and technology because roads are not a permanent phenomenon.
Sreehari cited some of the good roads in India and in Karnataka:
—The Grand Trunk (GT) Road that link Calcutta with Peshawar, stretch from Amritsar to Kolkata;
—The Bengalur-Mysuru stretch of NH-275;
—The Vidhana Soudha frontage road
All of these roads are constructed in concrete for long life
without sacrificing on quality construction or supervision.
Black top, or bitumen/asphalt roads, are designed for 10 to 12 years, but due to rain water penetrating various layers, their life is restricted to only 2 to 3 years. White top, or “cement concrete”/ concrete roads, are planned and designed for long life without much maintenance—[20-30 years], with the exception of possibly attending to joints [at times]. White topping or thin white topping of 10 cm can give life of more than 10 years without maintenance, but perfect drainage systems must be in place.
“Water is considered a dangerous enemy of black-topped (bitumen/asphalt) roads and a friend of white-topped (cement concrete) ones. Hence, water must not be allowed to stay on the surface of black-topped roads as stripping of bitumen aggregates takes place, subsequently leading to potholes on the roads. This has become a regular affair in urban areas of the state even as these potholes are filled unscientifically for reasons known best to the authorities,” wrote Prof. Sreehari .
With either type of road,
—Storm water must be drained well
—With longitudinal and transverse road gradients based on rainfall intensity of the region
—The sub-base has to be sufficiently strong
Causes of road failure are failure of these requirements, drains not cleared before rainy seasons/or frequently, and higher transverse slopes. While designing and constructing roads, there should not be any compromise in the quality of materials and the quantity of materials, and there must be good quality control stipulated in the code of practice. Finally, although skill is required for laying roads, supervision and quality inspection is a must during and after construction.
He concluded, “If these are supervised properly and inspected effectively, we will certainly have seen the last of the much familiar periodic failures of roads in our cities. That has been the secret of roads in Mumbai, Goa and other areas which experience heavy rainfall, which can be replicated in Karnataka too for our major and arterial roads.”
For the full New Indian Express article written by Prof Sreehari titled “Unravelling ‘secrets’ of good quality roads for our cities”, please go to: www.newindianexpress.com/states/karnataka/2022/jan/05/unravelling-secrets-of-good-quality-roads-for-our-cities-2403145.html