Guwahati: In Hajo, located some 30 kilometers from Guwahati, civil engineer Manoj Das is making waves with his innovative approach to sustainable and eco-friendly construction. Das, who is employed with the Public Works Department (PWD), is working on his plans for "environmentally sustainable" buildings by introducing a prototype built with bamboo.
He recently spoke to Business North East's Pankhi Sarma and shared some insights into his projects, bamboo technology, and its potential impact on rural economy.
During his time as a site engineer in 2000, Das said he witnessed the "degradation" of traditional building materials. "This ignited a spark in me, causing me to seek alternatives for sustainable construction with a particular focus on bamboo. My journey in this regard began with shuttering, paving the way for bamboo-based innovations," he said.
Initially, Das said, he found studies and research conducted by the US Navy and Prof. Khosrove from Sao Paulo University which revealed that bamboo can be used in the construction of shuttering and slabs in reinforced cement concrete (RCC) buildings. "Bamboo splits are used as construction elements and fibers within concrete are comparable to or even better than steel," he said, adding that once kept inside a medium like concrete, bamboo can last "indefinitely."
Upon being asked for the reason behind his usage of bamboo, Das shared, "Bamboo is a regenerative material, and a gift to the people of the Northeast. The historical significance of bamboo in construction and reinforcement cannot be understated." The main challenge, according to Das, was to concretize the bamboo due to its non cohesive nature and smoothness. "That's where I had to innovate", he said.
However, he pointed out, for bamboo to be suitable for construction, it must be matured "ideally for a minimum of five years." Das primarily relies on two bamboo species: bambusa tulda (locally known as jaati baah) and bambusa balcooa (locally known as bholuka baah). These bamboo varieties are well-suited for construction purposes due to their strength and resilience.
Das' prototype is a composite of bamboo with nominal use of steel, reducing the weight of structures while enhancing earthquake resistance. According to Das, the combination of bamboo and concrete forms an "effective and sustainable building material."
He further detailed his projects, which include a gallery and duplex built to test his innovative technologies using concrete over bamboo splits, used for slabs, roofing, and flooring, as well as reinforcement for support. The Assam Science Technology and Environment Council (ASTEC) provided vital support for this project with a Rs. 5.5 lakh grant.
A project is the development of a duplex measuring 1600 sq feet which features two slabs with minimal steel consumption and optimized use of concrete, combined with bamboo reinforcement. The use of bamboo extends to the walls of the structure, making them thinner while enhancing earthquake resistance due to the material's lightweight nature.
Taking it a step further, Das has also worked with bamboo on flooring and wall panels. The bamboo-based floors offer an anti-skidding surface while being four times more cost-effective and can be installed in as little as two days.
So what are are the advantages of Das' technology? Essentially, the bamboo-based construction could potentially help builders save crores. This approach reduces construction costs by over 40 percent when builders use Bamboo Reinforced Cement Concrete (BRCC). "In concreting over bamboo splits, the method employed in this prototype, a significant reduction of 50 percent in steel usage is achieved," he said.
Another additional advantage of bamboo-based construction is its reduced requirement for manpower. By utilizing fewer building materials and innovative construction techniques, less labor is needed. This sustainable construction technology offers another vital benefit – thermal comfort. Bamboo splits used in these structures are naturally thermo-resistant, acting as efficient insulators.
The innovator said he aims to promote sustainable development and inspire cultivation of more bamboo orchards and his efforts are focused on initiating a green revolution in the construction industry. Notably, the construction technology employed by Das has also received recognition in the form of two patent grants in 2021. "The bamboo-based construction methods demonstrated in these projects not only underscore the potential of bamboo but also signify a significant step towards sustainable and eco-friendly construction reflecting a commitment to a greener and more resilient future," Das said.
Das also underlined the significance of using locally available resources, especially in the North East, where bamboo is abundant. "This user-friendly technology has the potential to bolster rural economies and promote sustainable development", he said.
According to Rittick Hazarika, an architect from Guwahati who is also a member of resilient building construction committee in Indian Chamber of Commerce (ICC), the potential for expanding this model into homestays, Airbnb properties, and government initiatives like the Pradhan Mantri Awas Yojana (PMAY) is "substantial." Jayanta Pathak, the head of civil engineering department in Assam Engineering College (AEC) and also a member of resilient building construction committee in the ICC said innovations like these are on track to usher in a green revolution by "reducing carbon emissions by incorporating bamboo as a reinforcement material and composite."
