Sunday, November 19, 2017

Matvantage

Sturdy solutions

 

 

Bamcrete or reinforced bamboo concrete composites known as Bamcrete Technology has demonstrated tremendous potential of application in mass housing programmes. PROF ASHOK GUPTA, DEAN INFRASTRUCTURE, DEPARTMENT OF CIVIL ENGINEERING, IIT-DELHI and DR. KORDE CHAARUCHANDRA, FOUNDER, GREENBAM SOLUTIONS (NEW DELHI) elaborate on the possibilities of including bamboo in conventional building techniques. Sustainability, green development, eco-friendly and renewable are some of the buzz words gaining currency in present times. With rapid infrastructure expected in the wake of the new government there are mounting concerns towards the issue of ecological imbalance and an increasing clamour for a balanced model of development. How can destruction of the environment be averted further is a burning issue. What are the technologies in place to avert further destruction? Haritha-IITD Bamcrete (HIB) Technology is one such solution on offer in building sustainable infrastructure. 
 

 

 

Introducing Bamcrete

 

There have been attempts to replace steel in concrete with bamboo, a diverse material known for its good tensile strength. However, it has been proven well with decades of experience that bamboo in concrete when used for construction doesn’t bond well under dynamic loading conditions. This has inspired chemical experts to find a solution to this problem. In its present configuration, it is found to swell and shrink resulting in loss of bond, an aspect crucial to Reinforced Bamboo Concrete Composites. Bamcrete is different, in that it is out-of-the-box and utilises steel and concrete optimally at discrete locations to develop a rigid bond. It is proven to give consistent performance. It is much like engaging two bamboo poles with a steel and concrete composite to realise a batten. This discrete manner of engagement exposes bamboo to atmosphere along most of its length of structural element. With a pre-designed number of such battens, elements like columns, arches and beams can be developed as structural load bearing elements.
 

 

 

Origin

 

The technological development was initiated by the National Mission for Bamboo Application (NMBA) who discovered the true potential of the technology and funded a school, Haritha Ecological Insititute(HEI) in the tribal area of Paloncha near Khammam in Andhra Pradesh (now Seemandhara) to develop the concept. Thus the technology of joining bamboo culms rigidly was originally conceptualised and demonstrated with partial validation at HEI.

This development was recognised by the Centre for Rural Development & Technology and further nurtured at the Indian Institute of Technology (IITD), Delhi. The development process was initiated at IITD with funding support from the Housing and Urban Development Corporation (HUDCO), and additional support from Wasteland Development, Ministry of Rural Development (MORD), under its wasteland reclamation and livelihood generation project, and Indian Council of Agricultural Research under its National Agricultural Innovation Program through funding from World Bank, in a bid to set up a National Resource Facility on Bamboo Technology at IITD. Thus, the technology derives its name as Haritha-IITD Bamcrete (HIB) Technology or simply put, Bamcrete Technology.

The prime underlying goal towards development of Bamcrete Technology was “to equip the rural areas/ villages with the ability to process bamboo into a value-added product in the form of main load bearing structural elements, right at the village level and enable them to become the suppliers of certified quality structural elements for rural/urban/
agricultural infrastructure.” 

 

 

 

Relevance

 

With India poised for growth sustainability is expected to be a key trend in all future developments. With increasing concerns over global warming and climate change mass use of unsustainable materials like brick, concrete and steel the use of bamboo becomes increasingly relevant. Bamboo with its proven rapid regeneration potential, eco-healing capabilities, inertness to weather irregularities, soil conservation reclamation potential easily qualifies as  potential material for delivering sustainable infrastructure. Bamcrete Technology offer value addition to bamboo and enables it for developing desirable bending strength.

 

With around 120 species of bamboo available in India, and over 1,200 varieties across the world, the strength of the bamboo has seen variation. Even in a particular species, the strength of bamboo is found to vary on the basis of the agro-climatic zone and further on the location of the sample along its length. The key mechanical properties of bamboo along with their strength values has been  determined by researchers from across the world (Refer table 1.1). Bamcrete Technology enables bamboo of given mechanical properties to be integrated to deliver the desired strength. Concerns of durability are directed towards insect attack, fire and natural degradation. There are both chemical and natural treatment developed to prevent insect attack especially against borers and termites. There is formula available to protect bamboo from fire hazards unlike wood. Bamboo being a natural material degrades faster when exposed to sunlight and rain. Thus natural degradations can be averted through the above treatment and more so through adequate design of structure. IIT Delhi, through its various bamboo projects, has documented structures made with bamboo being 20, 40, 60 and 100 years old. The longest known life of bamboo application is in the main girder of the palkhi of Maharani Ahilyabai Holkar which is 250 yrs old!
 

 

 

Matter of cost  

 

Assuming the availability of all the materials, the major indirect cost to be paid is ecological cost. Over that, the cost of material and utilisation of material to develop a finished product depends on the availability of skilled man-power and material, supply chain logistics and above all government policies for its promotion. The potential local availability of bamboo as raw material across country will surely make it cost competitive as against brick, cement and steel.

 

 

 

Bamcrete Housing

A 1-BHK house of 27 sq m can be delivered at around Rs 400 sq ft by integrating the Indira Awas Yojana (IAY) and Mahatma Gandhi National Rural Employment Guarantee Act (MNREGA) with certain modifications. Our initial estimates suggest that such a structure can be erected within 20 days using around nine skilled laborers. In order to scale up the delivery of such structures at mass affordable housing levels, SMEs along with trained manpower need to be developed and supported through policy measures.

 

The quality assurance of load bearing structural elements being the prime aspect will require strategic intervention. This can come when in order to meet the demand for such structures the authorities take recourse to eco-healing measures i.e. through plantations.

 

 

 

Advantages 

Policy measures undertaken to channelise demand for affordable housing segment will lead to creation of SMEs in remote rural and tribal areas. Enhanced social acceptability will lead to a further need of urban/rural/agricultural infrastructure. Alternatively applications in the form of bamboo penthouses on urban roof tops will evolve to be the new signatures of an urban skyline; the space thus created for recreation will further reduce heat gain in the building’s roof top resulting in reduced air conditioning costs. With increasing social acceptability of bamboo, SMEs will derive sustenance by catering to the requirements of production and supply-chain logistics of structural elements for urban and rural houses, wall panels for multi-level housing, cattle shelters, vermi-compost sheds, poultry sheds, green houses, grain silos, solar dryers, cold storages using Bamcrete Technology at affordable cost.

 

 

 

Future

This technology has a potential to evolve into an indigenous technology affecting the socio-economics of India along with other countries in the region where the bamboo is found to grow in abundance. As per the 2011 census, with around 640 districts in India having 600,000 villages i.e. an average of 940 villages per district and an overall engagement of 14,000 people per district, it is being assessed that 1 crore people will gain employment through bamcrete technology in the course of the year. Crucial measures will need to be taken for development of building standards which will enable use of bamboo in construction; training of man-power in technology; development of  supply-chain logistics along with forward and backward linkages. Economic viability and not just charity or government grants will be crucial in massively scaling up of application of bamboo, notwithstanding the other positives on the ecological and social fronts.

 

Thus technology backed with policy interventions has a potential to bridge the rural-urban divide, reduce migration of rural youth to the urban areas, and to strengthen the rural economy even while providing sustainable support to both urban and agricultural infrastructure.
 

 

 


Acknowledgement:

A concept gets its realization through the team efforts. In realizing the bamboo concept at Haritha Ecological Institute and Indian Institute of Technology Delhi, we got a wonderful support from our funding agencies namely National Mission for Bamboo Applications (NMBA); Wasteland Development, Ministry of Rural Development (MoRD) and National Agricultural Innovation Program (NAIP), Indian Council of Agricultural Research (ICAR). We would also acknowledge the support extended by Mr. Mahendru, Bamboo Greens, for his kind support in extending his roof top for building a demonstration structure.

 

 

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Wednesday, November 12, 2014

Lowkya

Kindly help us with some more technical inputs


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