The use of stabilised Spanish clay soil for sustainable construction materials

This paper presents the potential manufacture, and the engineering properties, of producing an economical, ecological and sustainable building material using a Spanish clay soil. Cylindrical clay soil test specimens incorporating three types of commercials stabilizer additives i) Portland cement (PC), ii) Natural Hydraulic Lime (NHL-5) and iii) Hydrated Lime (CL-90-S) were used, on similar mix compositions for brick production. The investigations were carried out using a clay soil supplied by a rural bricks manufacturer. The laboratory results demonstrated that compaction effort, compressive strength, moisture content, rate of water absorption, density and durability (repeated 48-hours of freezing/thawing cycles) were all within acceptable engineering standards typical for clay masonry bricks. This paper has demonstrated that with the mix formulations tested, unfired masonry bricks can be manufactured at the appropriate optimal compaction and optimum additive content depending on the desired engineering properties and any other desirable brick characteristics.

► The manufacture and the engineering properties of producing an economical, ecological and sustainable building material from clay soil.
► Unfired clay bricks are a sustainable construction material with a great future in rural regions.
► Commercial additives have been used as clay soil stabilizers