Working towards sustainable building practice in Nepal by reducing the utilization of cement

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By Eline Sjølie Osmundsen

Spring 2022

 

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The development in Nepal has moved in the right direction throughout the last decades, and several improvements have taken place in the construction industry. However, the country is still in need of new housing, public buildings, and upgraded infrastructure. Especially the demand of housing units increased drastically after the earthquake in 2015, where more than 600 000 houses were destroyed. Modern materials like concrete is replacing traditional materials. The cement production is estimated to be doubled from 2020 to 2025. The increased use of cement is unfortunate for the sustainable development, and Nepal is already one of the countries disproportionately affected by climate change. In collaboration with the Samaj project and the Engineers without Borders the current building practices and measures improving the present situation in terms of reducing the amount of cement utilized have been examined. Hopefully it will be possible to find alternatives that can fulfil the requirements to the materials and at the same time leave smaller CO2 footprint. In addition, benefits from low cost, and having a positive social impact in the country are positive gains. In this project, two alternatives have been investigated by using three different research strategies: Literature review, experimental tests and field study. The first alternative investigated is substituting parts of the cement with clay, which is a raw material distributed all over Nepal. The second alternative being investigated was the sustainability of earth-based materials to replace concrete. From the investigations done, it is possible to conclude that substituting parts of the cement with calcinated clay is possible. However, unheated clay is proven to be unsuitable to use as a replacement for cement. The research also makes it possible to conclude that earth-based materials are suitable to use instead of concrete in some cases. Still, not all, and for usage in many constructions, concrete seems to be the only acceptable option.