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Achieving Unprecedented Milestones in Road Construction and Embracing Sustainability Practices

Larsen & Toubro (L&T), a leading Indian construction firm, has achieved two groundbreaking records in road construction. L&T’s Transportation Infrastructure arm successfully executed the longest road using the largest quantity of bituminous concrete in just 100 hours. The project serves as an exemplary model for reducing fuel consumption and mitigating the carbon footprint. It also underscores a strong commitment to sustainability and the pursuit of cost-effective practices. The article examines how L&T utilised bituminous concrete and cold central plant recycling technology to reduce resource consumption, energy usage and greenhouse gas emissions.

Setting new records

The Ghaziabad-Aligarh section of NH-34 holds immense significance as a vital road link connecting two densely populated cities in Uttar Pradesh. This critical trade route facilitates the movement of goods and connects industrial areas, agricultural belts and educational zones. The Roads, Runways & Elevated Corridor (RREC) Strategic Business Group, a part of L&T’s Transportation Infrastructure, took on the challenge of executing a record-breaking road construction project within a limited timeframe.

L&T embarked on an ambitious target of laying 100 lane kilometers of road in 100 hours. The project commenced at 10 am on 15 May 2023 and was scheduled to conclude at 2 pm on 19 May 2023. However, L&T surpassed its initial target by achieving an impressive 112.5 lane kilometers within the stipulated timeframe.

L&T’s accomplishment in the Meerut Aligarh Ghaziabad Road Project surpassed previous records set by other Indian construction firms. L&T laid 112.5 lane kilometers using 51,896 metric tons (MT) of bituminous concrete (BC) in 100 hours, surpassing the previous records of 84.4 lane kilometers in 109.8 hours and 42,666 MT of BC in 100 hours.

Innovative approaches

The successful execution of such a massive project within a stringent timeframe came with its fair share of challenges, including logistical complexities and the need for fast and efficient workflow management. Overcoming these challenges demanded a high level of expertise, adaptability and resilience on the part of L&T’s team. Furthermore, it required the implementation of innovative strategies and cutting-edge techniques. L&T employed state-of-the-art machinery, advanced paving technologies and efficient resource management. The project incorporated meticulous planning, real-time monitoring and collaborative efforts to ensure seamless coordination among various teams involved.

A team of 1,900 workmen and 250 engineers, worked round-the-clock with the help of 53 specialised road construction equipment to complete this stellar project. Cold central plant recycling (CCPR) technology played a crucial role in reducing fuel consumption, minimising the carbon footprint and optimising resource utilisation. This innovative green technology involved utilising 90% milled material obtained from existing road, which amounted to nearly 20 lakh square meters of road surface. The consumption of virgin materials was reduced to a mere 10%.

Emphasising sustainability and cost-effectiveness through CCPR and BC

In an effort to minimise costs associated with road and highway construction, the Indian government is actively exploring the incorporation of diverse ecologically sustainable materials. The objective is to achieve a harmonious balance between cost reduction and the promotion of sustainable practices within the construction industry.

The planning team of the Meerut Aligarh Ghaziabad Road Project prioritised environmental considerations in line with this growing emphasis on sustainable practices. One notable sustainability initiative undertaken was the utilisation of CCPR technology for the base course layer. By reusing existing road materials, the project significantly reduced resource consumption, energy usage and greenhouse gas emissions.

Sustainability focus: CCPR technology

Cold recycling is an excellent way to fix and upgrade roads in a cost-effective and sustainable manner. It involves the reuse of existing road materials which is already paid-for. This also minimises the need for fresh materials and reduces waste generation. In this process, old asphalt materials from existing roads, called RAP, are combined with new asphalt or special agents to create a cold recycled mixture. The good news is that this can be done without using heat and thus reduces energy consumption and greenhouse gas emissions.

Benefits of CCPR

There are different methods for cold recycling, and one of them is CCPR. In CCPR, the RAP materials are processed by milling them and then mixing them with bitumen emulsion at a separate location. This mixture is transported to the road construction site and paved using trucks. The compaction process is similar to other methods of road construction.

Using cold recycled mixture has many benefits.

• Cost-effective. The extensive use of recycled materials in the base course layer reduces the reliance on virgin resources. By minimising the extraction of new materials, L&T contributed to the conservation of natural resources. Also, studies have shown that cold recycled mixtures are better at preventing cracks compared to regular asphalt overlays. When the overall costs of cold recycling projects were analysed over their lifespan, they were found to be lower than projects using regular asphalt.
• Energy-efficient. Another advantage is that cold recycling reduces energy consumption by 56-64% and decreases greenhouse gas emissions by 39-46%. When we look at the performance of the road over time, it shows similar trends to regular asphalt in the first two years.
• Greenhouse gas emission reduction. The reduced reliance on fresh materials and the associated transportation and processing requirements resulted in a notable reduction in fuel consumption and greenhouse gas emissions. By adopting CCPR technology, L&T demonstrated its commitment to mitigating the environmental impact of road construction.CCPR is a smart and sustainable approach to road construction and rehabilitation. It saves money, protects the environment and maintain good road conditions for a long time.

Challenges in using CCPR

The implementation of CCPR technology presented challenges such as material selection and testing, and optimisation of the construction process. L&T addressed these challenges through meticulous analysis, advanced testing techniques and efficient workflow management.

What is CCPR?

Cold-mix recycling is performed by combining reclaimed asphalt pavement (RAP) materials with virgin asphalt and aggregate (if required) in a central mixing plant without the application of heat.

• Material selection and testing. Selecting the appropriate milled material for recycling and conducting thorough testing to ensure its suitability as a base course layer required meticulous analysis and quality control measures. L&T’s project team employed advanced testing techniques to verify the characteristics and performance of the recycled material.
• Construction process optimization. The successful implementation of CCPR technology necessitated efficient construction processes. L&T optimised the workflow, coordination and equipment utilisation to ensure seamless integration of the recycled materials into the road construction, while meeting the project’s stringent timeline.L&T’s adoption of CCPR technology in the Meerut Aligarh Ghaziabad Road Project reflects L&T’s dedication to sustainable infrastructure development and sets a positive example for the industry as a whole. Moving forward, incorporating such sustainable techniques in construction projects can contribute to a greener and more environmentally responsible future.

Use of BC as an ecologically sustainable material

The objective of bituminous recycling is to restore the properties of the RAP so that it performs like fresh mix. This process entails blending the RAP with fresh bitumen, rejuvenators and new aggregates in appropriate proportions.

BC is widely employed for surfacing roads and highways due to its exceptional durability, flexibility and capacity to withstand heavy traffic loads. It not only provides a smooth and comfortable driving surface but also effectively safeguards the underlying layers of the road.

Moreover, BC can be tailored to meet specific project requirements, offering flexibility in terms of thickness, mix design and surface characteristics. This adaptability enables the implementation of customised solutions based on factors such as traffic volume, climate conditions and other pertinent considerations. The dark color of BC enhances the aesthetics of roads, providing a visually appealing surface that complements the surrounding environment.

Advantages of BC in road construction

• Durability. BC is renowned for its resilience and ability to withstand wear and tear, making it an ideal choice for areas with heavy traffic loads and challenging weather conditions. The extreme summer heat, prolonged monsoon season and harsh winter temperatures in Uttar Pradesh make BC particularly suitable for road construction in the region.

What is BC?

BC, a type of asphalt pavement material, is widely used in CCPR. It comprises a mixture of aggregate (such as crushed stone, gravel, or sand) and bitumen (a sticky, black, and viscous liquid). The aggregate provides strength and stability to the pavement, while the bitumen acts as a binder that holds the aggregate particles together.

• Quick installation. BC can be efficiently and rapidly laid, enabling faster construction and minimised road closure time. This leads to minimal disruption to traffic flow and shorter construction schedules.
• Cost-effectiveness. Compared to other alternatives, bituminous concrete is a cost-effective pavement material. Its efficient installation process, lower maintenance requirements, and extended service life contribute to overall cost savings.
• Recyclability. BC is recyclable, allowing it to be reclaimed and reused in future road construction projects. This helps reduce the demand for virgin materials and minimises waste generation.

Typical challenges involved in using BC

While BC offers numerous advantages, it also presents some challenges when used in road construction

• Environmental impact. The production and use of BC can have environmental implications due to its reliance on non-renewable resources and the release of greenhouse gases during the manufacturing process. Proper management of BC waste and prevention of harmful substance leaching into the environment are crucial.
• Skill and expertise. Achieving the desired performance and longevity of BC roads requires proper installation and compaction techniques. Skilled personnel and specialised equipment are necessary to ensure accurate mix proportions, adequate compaction and a uniform surface finish.
• Quality control. Maintaining consistent quality across different batches of BC can be challenging. Implementing quality control measures throughout the manufacturing and construction processes is necessary to ensure compliance with specifications and standards.L&T has taken on the responsibility of addressing these challenges through proactive planning, meticulous execution and continuous monitoring and maintenance.

Excellence in road infrastructure

The successful execution of the Meerut Aligarh Ghaziabad Road Project exemplifies L&T’s ability to overcome challenges and leverage cutting-edge techniques to deliver high-quality infrastructure within demanding timelines. Furthermore, L&T’s emphasis on sustainability, demonstrated through the use of BC and CCPR technology, contributes to a greener and more environmentally responsible future.

With an unwavering commitment to excellence and a focus on sustainable practices, L&T has consistently delivered transportation infrastructure that is durable, environmentally responsible and of the highest quality. Its dedication to surpassing industry standards has ensured the successful implementation of projects that meet the stringent requirements and long-term needs of the community.  It has undertaken and delivered large-scale infrastructure projects spanning various sectors such as metro rail systems, airports, bridges and elevated corridors. These projects have far-reaching impacts on improving transportation networks, fostering economic growth and ultimately improving the quality of life for the people of India.

This article was written by the L&T EduTech editorial team.

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