Sustainable rammed earth structure: A structurally integral, cost-effective and eco-friendly alternative to conventional construction material

Abstract

While constructing (developing) any structure (asset), its impact on the environment should always be assessed. As we know, cement is a key building material that is commonly used but also creates pollution during its manufacturing, storage handling, transportation and usage. So, what-if this building material can be significantly replaced by some other building material that is far eco-friendlier. Mother Nature i.e. our planet Earth offers us naturally existing and abundant Soil (mud) that can be used as an alternative building material. Cement, as a main component of construction material mix, when replaced by naturally and locally available mineral soil (in different proportions) will result in reduced carbon footprints which otherwise is high for cement supply chain. This nature’s gift in the form of mineral soil has inspired the idea of Rammed Earth Construction. This is not an invention; it is an innovation through traditional (well placed) wisdom. Natural soil with additives (if required) in designed/customized amount are compacted in layers within sturdy formwork. From series of field experiments we conducted, the proportions for the components like Soil, (part) Cement and Fly Ash were determined. The proportion of these constituents mainly depends on local availability and climatic condition in & around the construction site. The resultant construction product mix is a monolithic wall structure with superior thermal insulation properties, fire resistant and most importantly eco-friendly. The Due to use of soil, the wall absorbs heat during day time and slowly cools down in night time. This phenomenon results in effective insulation system. This moderates daily temperaturevariations and reduces the need for HVAC systems, which helps in attaining the green building objective. One of the prominent features of Rammed Earth Structure is its cost efficiency. The main component is naturally available mineral soil and other resources required are also available at a comparatively low cost. A structure (say home wall) can be built using Rammed Earth in approximately 1/5thcost than that required for Stone wall. So, Rammed Earth based construction projects can be linked to Government’s Low-Cost Housing schemes like Pradhan Mantri Awas Yojana (PMAY, PMGAY). For building Rammed Earth Structures, unskilled labors can be easily trained and hence creates a good opportunity to employ unemployed people including locals. In this way this project can tangibly contribute to bring about a socioeconomic shift/change.