Indian Institute of Technology Hyderabad (IITH) researchers have developed ‘Models and Computational Simulation Studies’ to predict performance of road surfaces or pavements and compare these predictions with conventional road designs.
Construction of road surface is a complex process as it must provide for comfortable riding quality, good skid resistance, favourable light-reflecting characteristics and low noise pollution. This research offers a route to accurate prediction of road surface performance, which can help in construction of long-lasting roads in India.
A road surface consists of superimposed layers of various materials above the natural soil and help in the distribution of the load of the traversing vehicles for a smooth ride. These could be rigid and flexible. While rigid pavements are made of high-strength concrete to resist the vehicle load directly, flexible pavements transmit the load downwards from the surface through successive layers of materials.
“Flexible pavements on Indian roads are more advantageous as they are adaptable to stage-wise construction, can be made of low-cost materials and can be easily opened and patched” said Prof. Sireesh Saride, Department of Civil Engineering, IIT-H.
Through a modelling technique — ‘Reliability-Based Design Optimisation (RBDO), it is possible to check reliability assessment of road surface structures. Prof. Saride’s team, including B. Munwar Basha, associate professor and research scholar P.R.T. Pranav used RBDO to predict safety of multi-layered flexible road surfaces.
Flexible pavement has four layers – sub-grade, granular sub-base, base, and bitumenous. Modelling studies showed that bituminous layer’s thickness and resilient modulus of the base layer are most influential parameters for the road failure. Accurate prediction of pavement performance has become important to develop robust design procedures, he said. Their work has been recently published in the Journal of Transport Engineering, a reputed peer-reviewed journal.
India has the second largest road network in the world, after the United States, and has about 4.37 km of roads per 1,000 people. Indian roads are of different types including highways, alleyways, paved roads and unpaved roads and as of 2016, 62.5% roads were paved. The Ministry of Road Transport and Highways aims to construct 65,000 km of national highways by 2022 and such ambitious projects would benefit from the current study, a press release said.