Concrete roads offer several distinct advantages over roads with bituminous surfaces. With barely 2 percent of the country’s road length constructed from concrete, there is tremendous scope for enhancing the durability and strength of roads through concretisation. A look at the technological advancements in concrete technology and the present scenario in IndiaThe importance of concrete roads can be gauged when one travels on the Mumbai-Pune Expressway which was built of concrete in the early nineties. Prior to that, people would travel on the old Mumbai-Pune road which was rugged, uncomfortable and would take a lot of time. However, with the opening of the Mumbai-Pune Expressway, time taken to traverse the distance has reduced, there is a saving of fuel and there is less wear and tear of vehicles due to the strong surface of the road, leading to lesser resistance.Case for concrete roads:In a vast country like India with a large geographical area and extreme weather patterns, the roads need to be built with a material which does not suffer from the frailties exhibited by bitumen. The material should be in a position to withstand pressure from petroleum and oil spillage, abrasion, high axle loads, aggressive pollutants and high traffic densities. It has been proved through technical studies in India and the world, that concrete roads satisfy all the aforementioned conditions. Commenting on the advantages of concrete roads over bituminous surfaces, Dr LR Kadiyali, CEO of LR Kadiyali & Associates stated, "roads made from concrete are practically maintenance free. They are comparable in initial cost to a flexible pavement on a new road with heavy traffic and cheaper on a life-cycle basis. It leads to a 15 percent saving of diesel in the case of commercial vehicles and a 10 percent saving in electricity for street lighting. Concrete roads ensure a better performance under conditions of heavy rainfall and water logging." Usage of concrete roads leads to a saving of around 40 percent in stone aggregates.Since the structural capacity in rigid pavements is ensured by the slab itself, the maintenance expenditure incurred on concrete roads is relatively low. New techniques and technologically advanced equipment have ensured that concrete roads are easy to build. There are lesser traffic disruptions as concrete roads remain maintenance free for a longer period. Concrete road surfaces offer better skid resistance and are not impacted due to water and the bad effects of oil and lubricant spillage.Elaborating on the advantages of concrete roads, Prof M.S.Shetty, Founder Chairman of the Pune Chapter of the Indian Concrete Institute (ICI) noted, "though the initial cost of making a concrete road is higher as compared to a bituminous road, it has a shelf life of around 25-30 years with minor repairs. The cost of concrete roads is lesser in the long term."Concretisation of roads also ensures savings in fuel consumption. It has been shown through trials undertaken by the Central Road Research Institute (CRRI) that around 15-20 % less fuel is consumed by goods carriers on concrete roads as compared to bituminous roads. Wear and tear for vehicle tyres, suspensions and shock absorbers is reduced.Through the application of life cycle cost analysis, one can deduce that the cost of concrete roads can match those of flexible pavements within 10 years. Though the initial cost of building a concrete road is higher, the scales begin to tilt in favour of concrete roads within a period of 5-10 years. In this time gap, flexible pavements require repairs to enhance their longevity. The life cycle cost of concrete roads becomes cheaper by 10-15 percent over a period of 20 years as compared to bituminous roads. Utilisation of fly-ash based blended cements enhances the cost competitiveness of concrete pavements.Concrete roads in India :The earliest example of a concrete road in India is Mumbai’s famous landmark Marine Drive which was constructed in 1939. This stretch of road is the most apt example of the durability and strength exhibited by concrete surfaces. There has scarcely been a day when Marine Drive was closed for repairs or maintenance. This seafront road has displayed resilience even seven decades after its construction.Commenting on the construction of concrete pavements in India, Dr L R Kadiyali stated, "around 2000 kms of concrete pavements have been constructed under the National Highway Association of India (NHAI) project. Other concrete road projects include the Mumbai-Pune Expressway which is around 100 kms and the Taj Expressway which is around 120 kms. All the concrete roads constructed are performing well."Elucidating on the construction of concrete roads in Mumbai, Mumbai Metropolitan Regional development Authority (MMRDA) Joint Project Director, Dilip Kawathkar stated, "a classic example of a concrete road is the Santacruz-Chembur Link Road (SCLR). It is expected to be completed by December 2012. The road will be a double decker flyover almost 6.5 km long. It will comprise of a 6 lane concrete road with a 3 metre wide footpath."Some prominent concrete roads in India includes the new carriageway of Delhi-Mathura road in Haryana/UP, it is 111 kms long and comprises of a new 2 lane carriageway in concrete, the Satara-Kolhapur section of NH-4 in Maharashtra is 133 kms long and has a new 2 lane carriageway in concrete, a 30 percent fly ash replacement has been used in the construction of the carriageway, the Yamuna Expressway is 165 kms long and has a new 2X4 lane carriageway in concrete under construction, the Khaga-Varanasi section of NH-2 in UP is 202 kms long and has a new 2 lane carriageway in concrete.Bitumen:In India, the material long preferred for road laying has been bitumen, a by- product of the petroleum industry. However, bituminous surfaces suffer from certain disadvantages. It rapidly deteriorates due to climatic conditions and rapid wear and tear. The most common signs of the drawbacks of bitumen roads are potholes. Bituminous surfaces also suffer on account of impact by water, oxidation, sunlight, spillage by petroleum and lubricants. The roads are also pressured by over laden vehicles such as heavy trucks and buses.Technological advancement:Road building in India has witnessed a tremendous technological advancement over the last few years. The pace of road construction has been accelerated alongwith an improvement in the quality of roads. This has been possible due to the evolution of advanced technology and sophisticated equipment. The use of Ready Mix Cement (RMC) has also led to the revolutionizing of road building. The major advantages accrued on account of the use of RMC are long term savings and faster construction. It also eliminates the disadvantages of hand mixed concrete which is dependent on traditional labour.Commenting on the latest technological developments in the construction of concrete roads, Dr Kadiyali stated, "developments in the construction of concrete roads comprise of continuously reinforced concrete pavement, which eliminates joints and whisper concrete which reduces noise levels. High volume fly-ash concrete has replaced cement by around 50 percent. Technological developments also comprise of manufacture of high strength concrete thro-ugh use of additives like silica fumes and white topping."The construction of concrete roads has become not only speedier but also economical through the deployment of different technological inputs. Elucidating on this aspect, Prof.Shetty stated, "one metre per minute of concrete road can be constructed in a day through what is known as the horizontal slip form technique. In this technique, used for pavement and traffic separation walls, concrete is laid down, vibrated, worked and settled in place while the form itself slowly moves ahead. This technique was used in the Delhi-Mathura road in 1992-93." The horizontal slip forming method finds its origin in the construction of interstate highways initiated by the Eisenhower administration in the USA during the 1950s.The Way Forward:Indigenous research on various aspects of concrete road design should be taken up. The performance of concrete roads already constructed should be monitored and any deficiencies observed should be identified. State public works departments (PWDs) should take up concrete road projects on the state highways just as the Central govt. is taking up projects on the national highways. The cement industry may fund a few pilot projects of white-topping in cities.A well developed and technologically advanced road network is absolutely essential to maintain and enhance the progress of a rapidly advancing economy like India. The building of a well heeled and efficient road system will result in the transportation and distribution of various goods and services across the country which is geographically vast and diverse. The utilisation of concrete in roads will not only ensure a long term investment in a strengthened road network but also lead to rapid economic progress.Cohesion needs to be maintained between the central and state governments as well as different organisations in order to ensure that a certain standard and quality of roads is maintained.