Research Projects

Maintenance and repairs of bituminous pavements during the life cycle are one of the major investments in a country’s economy and a predominant resource-consuming field with a deep link with environmental pollution. Fatigue cracking, a major distress in the pavements, often manifests in the form of potholes and needs timely and suitable maintenance treatment. Research on developing self-healing pavements, which can heal the cracks upon the application of different heating techniques, such as electromagnetic induction, microwave and infrared methods, has been extensively carried out in many countries. In India, research and implementation on developing self-healing pavements is in a nascent stage. While it is important to learn from the experiences of other countries, it is equally necessary to develop indigenous maintenance technologies and strategies for self-healing pavements in the country. The present study proposes a two-stage maintenance strategy - the application of microwave energy (MW) followed by the application of compaction energy (roller pass) for heating the pavements and healing the distresses such as potholes, cracks, and permanent deformation. Thus, this study aims to develop an indigenous microwave heater assisted by rolling which can generate uniform heating patterns in the pavement slabs and heal the fatigue damage. The design of the microwave heater would be based on the finite element analysis and simulation of a model structure and the optimisation of the geometry. For better microwave absorption and uniform heat distribution, two techniques are proposed in this study. They are: 1) Improving the microwave absorptivity of the natural aggregates present in the mixture by the addition of industrial waste-steel slag material. The surface of the steel slag material would be modified by a novel, low-cost technique named Co-precipitation for a stable and more MW-absorbing steel slag. Utilising steel slag in bituminous mixtures not only improves the microwave absorption, but also can be a viable solution to the slag disposal, which is proposed in this study. The dielectric, structural and mechanical properties of the modified mixtures would be evaluated to optimise the dosage of the steel slag. 2) Designing an impedance matching layer of suitable material and geometry to enhance the heat absorption and produce uniform heat distribution in the mixtures. It is proposed to design and fabricate an indigenous microwave heater assisted by a roller on a laboratory scale to carryout heating and healing experiments and fine-tune the numerical models. The life cycle cost assessment and the benefits of the proposed strategy and the materials used (steel slag) will be quantified in terms of the reduction in GHG emissions and prolonging of fatigue life.