Green Roads India A Concrete Future

Infrastructure development in India, while crucial for economic progress, is increasingly facing scrutiny for its detrimental environmental consequences.

A stark reality emerges from the relentless mining of mountains for essential construction materials like rough stone, gravel, and sand, directly impacting the nation’s delicate ecological balance. The unchecked extraction is triggering a cascade of environmental issues, including the disruption of vital hydrological cycles, altered weathering patterns, depletion of groundwater levels, loss of crucial green cover, and a significant decline in biodiversity across the subcontinent. The scale of this extraction is staggering. In Tamil Nadu alone, over 2,000 stone quarries operate, collectively churning out approximately 400,000 tonnes of manufactured sand (m-sand) daily, alongside a substantial volume of other raw materials. The repercussions are felt far beyond state borders. The Kanniyakumari district administration reports an alarming daily transit of nearly 50,000 tonnes of quarried stones destined for Kerala, underscoring the inter-state environmental burden imposed by this demand. This relentless exploitation of natural resources necessitates a critical re-evaluation of India’s infrastructure strategy and policy frameworks.

A particularly concerning aspect highlighted by recent data is the short lifespan of traditionally constructed asphalt roads. With roads often requiring rebuilding every five years, the current approach demands a continuous and unsustainable consumption of natural resources. India’s road network, the second largest globally at an astounding 6.671 million kilometers, including Tamil Nadu’s extensive 270,000 kilometers, bears the brunt of this. Astonishingly, constructing just one kilometer of a 10-meter wide asphalt road necessitates a staggering 2,000 tonnes of natural resources. The financial implications are equally significant. In the fiscal year 2023-24, the Tamil Nadu Highways department allocated a substantial ₹6,033 crore for the construction of 3,078.2 kilometers of roads, averaging ₹1.9 crore per kilometer. This translates to an estimated consumption of approximately 6.15 million tonnes of stone – for roads with a mere five-year lifespan.

However, a viable and environmentally conscious alternative exists in the form of concrete roads. While the initial investment for concrete roads is higher, their long-term advantages present a compelling case for a paradigm shift. For instance, a 1-kilometer asphalt road with a 7-meter width costs approximately ₹95 lakh and lasts only five years. In contrast, a concrete road of the same dimensions entails an initial outlay of ₹2.15 crore but boasts a lifespan of up to 60 years with minimal maintenance requirements. Beyond longevity, concrete offers additional environmental benefits. Its reflective properties help mitigate the urban heat island effect, contributing to cooler and more sustainable urban environments. Furthermore, concrete demonstrates superior recyclability compared to asphalt, thereby reducing construction waste.

Research from MIT’s Concrete Sustainability Hub indicates that concrete roads can lead to fuel savings of up to 3% due to lower rolling resistance. Their extended lifespan of 30 to 50 years, coupled with reduced maintenance needs and superior performance across diverse climates, translates to lower pollution and operational costs. In the Indian context, a 3% daily fuel saving equates to over 20,000 metric tonnes of fuel, resulting in significant reductions in both pollution and operational expenditure. The economic advantages extend to toll collections, a significant revenue stream for road maintenance. In 2023-24, the National Highways Authority of India (NHAI) collected ₹55,882.12 crore nationwide, with Tamil Nadu contributing ₹4,221 crore. Wider adoption of concrete roads, with their inherent durability and lower maintenance needs, could potentially lead to a reduction in the necessity for such high toll collections, ultimately benefiting taxpayers.

While challenges such as higher upfront costs, longer curing times, surface noise, and slower initial construction exist for concrete roads, innovative solutions are readily available. Rapid hardening cement can drastically reduce curing times from the conventional 28 days to just seven. The utilization of precast concrete slabs, manufactured offsite, can significantly expedite the construction process. Addressing road safety concerns, grooved or brushed concrete surfaces enhance traction, particularly crucial in wet conditions, thereby minimizing the risk of skidding. Noise concerns can be effectively mitigated through diamond grinding techniques, which create a smoother and quieter surface without compromising skid resistance. Looking towards the future, emerging technologies hold immense promise for further revolutionizing road construction. 3D printing of roads and the development of novel concrete compositions have the potential to significantly reduce both costs and environmental impacts. Self-healing concrete, capable of autonomously repairing cracks, and smart concrete embedded with sensors to provide early warnings about wear and tear represent groundbreaking advancements. Ongoing research is also focused on developing textured concrete that matches the smoothness and comfort of asphalt, aiming to integrate the superior qualities of both materials.

The adoption of concrete roads aligns seamlessly with several Sustainable Development Goals (SDGs), including SDG 9 (Industry, Innovation and Infrastructure), SDG 11 (Sustainable Cities and Communities), ¹ and SDG 13 (Climate Action). ² It is imperative for India to prioritize investments in these innovative technologies and embrace a long-term vision for road construction, striving for a paradigm of 100-year durability and minimal environmental impact. The time has come to prioritize the long-term well-being of the planet over short-sighted gains, valuing ecological sustainability above unsustainable infrastructure practices, and striving for a harmonious balance that ensures a resilient future for all.

Green Roads India A Concrete Future