Rammed earth construction with granitic residual soils: The case study of northern Portugal

Building in unstabilised rammed earth results in low environmental impact. However, northern Portugal has not historical tradition with this technique, and thus the suitability of the local granitic residual soils is unknown. This paper presents an experimental investigation, where this possibility is assessed. The results showed that these soils are unsuitable, and that rammed earth construction is only feasible if these soils go through a stabilising process. The alkaline activation of fly ash was investigated as an environmentally friendly stabilisation technique, and it proved to be capable of improving the performance of rammed earth.