Mechanical and Thermal Performance Characterisation of Compressed Earth Blocks

• Published in: Energies (Basel) Vol. 13; no. 11; p. 2978
• Main Authors: Teixeira, Elisabete R., Machado, Gilberto, P. Junior, Adilson de, Guarnier, Christiane, Fernandes, Jorge, Silva, Sandra M., Mateus, Ricardo
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.06.2020
• Subjects: Absorption; Accelerated erosion; Accelerated tests; Building construction; Building envelopes; Capillarity; Cement; compressed earth blocks (CEBs); Compressive strength; Construction costs; Durability; Electrical resistivity; guarded hot box; Heat conductivity; Heat transfer; Heat transfer coefficients; Masonry; Mechanical properties; Particle size; Particle size distribution; Porosity; Quality; Rain; Repair & maintenance; Size distribution; Soil mixtures; Soil porosity; Studies; Sustainable materials; Thermal insulation; thermal transmittance; Water absorption; Portugal
• ISSN: 1996-1073; 1996-1073
• DOI: 10.3390/en13112978

The present research is focused on an experimental investigation to evaluate the mechanical, durability, and thermal performance of compressed earth blocks (CEBs) produced in Portugal. CEBs were analysed in terms of electrical resistivity, ultrasonic pulse velocity, compressive strength, total water absorption, water absorption by capillarity, accelerated erosion test, and thermal transmittance evaluated in a guarded hotbox setup apparatus. Overall, the results showed that compressed earth blocks presented good mechanical and durability properties. Still, they had some issues in terms of porosity due to the particle size distribution of soil used for their production. The compressive strength value obtained was 9 MPa, which is considerably higher than the minimum requirements for compressed earth blocks. Moreover, they presented a heat transfer coefficient of 2.66 W/(m2·K). This heat transfer coefficient means that this type of masonry unit cannot be used in the building envelope without an additional thermal insulation layer but shows that they are suitable to be used in partition walls. Although CEBs have promising characteristics when compared to conventional bricks, results also showed that their proprieties could even be improved if optimisation of the soil mixture is implemented.