Innovative technologies to construct green resilient roads
In India, around 60 per cent of rural roads are in poor condition affecting the safety and mobility of goods and people. To overcome the issues, India is progressively adopting new technologies to develop road infrastructure. It is a need of the hour to adopt innovative technologies for constructing roads with extended life cycles with reduced use of aggregates and bitumen to mitigate emissions and carbon footprint, writes Himanshu Agarwal, COO, Zydex Industries Pvt Ltd. The longevity of pavements refers to their ability to perform to a specific design life with minimal maintenance requirements. Construction of structurally sound pavements necessitates to study of the traffic parameters, material properties, environmental conditions, proposed design, construction methodologies, and plan for maintenance and rehabilitation. Conventional approaches depend on old technologies that make use of high-quality paving materials. The primary factor contributing to its continued use is its widespread awareness. These technologies have several limitations, including excessive utilisation of natural resources, rapid depletion of aggregates, dated techniques, poor riding quality, long hauls of construction materials, excessive pollution, etc. To address these issues, it is necessary to incorporate innovative technologies on a larger scale in the road industry. These initiatives target to utilisation of existing resources ensuring cost-effectiveness and sustainability effectively. Objectives of new, emerging technologies are: Enable construction of water-resistant, durable roads with smooth riding quality. Enhance the strength of various layers and further the cause of building resilient pavements with higher design life Allow the use of in-situ material with stabilization techniques, faster construction, allow the use of marginal & waste materials, extend the paving season and also save fuel. Different layers of pavement should act as monolithic layers with use of technology additives for better fatigue performance. Technologies presently being adopted New technologies are being developed to tackle the construction issues encountered by constructors, as well as to overcome the limitations of current paving materials that have a detrimental impact on pavement lifespan. Some of the technologies include warm mix, cold mix, and recycling technology. Warm mix technology (WMA): Asphalt mixes are produced at temperatures (160–180 °C). It consumes a lot of fuel and causes damage to the environment. WMA technology additives reduce mixing and compaction temperature by 20 - 35°C, give better workability of mixes and enable to get compaction densities. The use of additives eliminates moisture susceptibility, extends paving seasons and help in achieving long-lasting road infrastructure. Cold mix technology: The cold mix technology is suitable where aggregates are moist due to high humid environment, in rainfall zone, hills and establishing hot mix plan is a challenge. Bitumen emulsion is mixed with aggregates at ambient temperature, thus saving the environment and fuel. The use of innovative technologies creates a chemical bond between aggregates and bitumen binder to impart water resistance, better workability to mixes and improve pavement performance economically. Recycling technology: Road agencies are encouraging the recycling of existing distressed roads to save on scarce aggregates and reduce the overall cost. The reclamation process includes hot in-place recycling (HIR), cold in-place recycling (CIR), and full-depth reclamation (FDR). All these technologies require a train of equipment, stabilizing agents, rejuvenators, or additives. The addition of additives with cement in FDR materials / soil-aggregate mix build water resistant and durable (unaffected wet-dry cycles) stabilized base / FDR. Using additives helps to construct strong bases with reduced thickness of the bituminous layer. It saves cost due to the minimal utilisation of virgin materials like bitumen and aggregates, enabling faster construction and longer life. Way forward There is a need to implement new technologies across Federal and state roads at one go by asset owners. Most important is to develop a three-tier quality control & quality assurance mechanism for monitoring construction quality and riding surface quality thru the design life. Innovative technologies contributing to the construction of sustainable, environment-friendly, cost-effective road infrastructure must be given priority. Pavements are a force multiplier in the economy and it is imperative to build sustainable resilient road infrastructure. About the author: Himanshu Agarwal is the Chief Operating Officer of the roads division of Zydex Industries Pvt Ltd. He has over three decades of experience in marketing technologies, consumer products, services & industrial chemicals. Agarwal is Co-Chair of Infrastructure Committee at PHD Chamber of Commerce & Industry (PHDCCI), New Delhi.