IMPROVING RAMMED EARTH WALLS' SUSTAINABILITY THROUGH LIFE CYCLE ASSESSMENT (LCA)

Rammed earth, an ancient construction technique based on compacting soil in progressive layers into formwork, has recently seen renewed interest due to its low environmental impact compared to traditional wall systems. However, the choice of soil and the addition of stabilisers to improve material durability and strength could jeopardize these environmental benefits. The focus of this paper is the lifecycle environmental impact of a typical rammed earth wall in Perth, Western Australia. The goal is to estimate variation in the structure's sustainability according to the materials used. Several soil mixtures, conventional and innovative ones, as well as recycled and waste materials (e.g. recycled concrete, fly ash and carbide lime) were considered for the analysis. Durability tests were performed to compare specimens' mechanical performance and their resistance to erosion. The sustainability analysis of the building material is therefore extended from the construction phase to the entire lifecycle, as recommended by the LCA standards. Results indicated that the choice of the mixture's components and their source could significantly affect the overall environmental performance of the structure. Even though every soil has different characteristics, materials similar to the ones considered here could be sourced anywhere and the results could be adapted to different geographical areas.