Improvement of Mechanical Properties of Compressed Earth Blocks with Stabilising Additives for Self-Build of Sustainable Housing

Abstract

Earth building technologies are increasingly being used to promote a natural and sustainable construction model and to empower self-building in resource-limited areas. This work focuses on investigating the use of different types of stabilising additives in compressed earth blocks (CEBs). To this end, empirical studies and laboratory analyses of earth samples taken from different sites in Ecuador were combined. Once the most suitable earth for use as a building material was determined, four types of CEBs were produced using equipment designed ad hoc to encourage self-building: earth-based, fibre additives, cementitious additives, and additives of other origin. The panels were characterised by means of compression tests to analyse their mechanical behaviour, obtaining the most promising results for the additivated samples with the highest percentage of cement and for the sample containing ground reeds, with a compressive strength of 3.3 MPa and 0.7 MPa, respectively. These samples were then subjected to more extensive tests using digital image correlation to analyse their full field strains and cracks, where the samples stabilised with cement showed a more homogeneous and consistent behaviour. Finally, an economic and comparative study with conventional construction systems was carried out to demonstrate the feasibility of using the proposed earth materials for cleaner and more economical buildings, mainly due to cost savings and lower pollution in terms of transport when using local resources.