Soil mineralogical composition effects on the durability of adobe blocks from the Huambo region, Angola

摘要

After many years of war, great efforts have been made for the socio-economic development of Angola,particularly in the construction industry. Among the construction techniques, adobe is one of the most usedin the province of Huambo, especially by low-income families, which constitute the majority. Thistechnique was established as an intangible heritage in the culture of that population. Huambo province islocated in the central region of Angola (Central Plateau). Adobe blocks are building elements withpotential degradation by the action of water. Due to the subtropical climate, hot and humid, andgeomorphology of the province, located at about 1000–2000 m of altitude and with an extensive riversystem, these buildings can be vulnerable and may present premature degradation, exacerbated by the lackof knowledge concerning the properties of the geomaterials used and techniques/solutions that allow theirstabilization and conservation. This paper aims to present the main results of the study to investigate theinfluence on adobe performance in regard to the mineralogy and geochemistry of soils used in theproduction of adobes used in the construction of dwellings. The knowledge gained with this research cansupport the development of solutions for the common anomalies and problems in this construction, as wellas to improve the strength and durability of the adobe units. For this purpose, soil samples were collectedand mineralogical, geochemical, and physical tests were performed. Durability and erodibility tests werealso performed on selected adobes, following the Geelong method. The results obtained with this researchmay contribute to the development of the knowledge concerning this sustainable building solution, whichhas a strong presence in the province of Huambo and neighbouring regions.