http://hdl.handle.net/10174/14391 Sat, 04 Apr 2026 05:39:24 GMT 2026-04-04T05:39:24Z http://hdl.handle.net/10174/17370 Title: Influence of anisotropy on the mechanical properties of Baixo Alentejo flysch rocks (Portugal) Authors: Pinho, António B.; Duarte, Isabel M.R.; Rosa, Francisco R.S.; Rodrigues-Carvalho, José A. Editors: Hassani, Ferri; Hadjigeorgiou, John; Archibald, Jamie Abstract: This paper aims to contribute to the knowledge of the mechanical properties of the shales and greywackes which constitute the flysch-type deposits of the Baixo Alentejo Flysch Group, in the south of Portugal. These formations are flysch-type deposits constituted by sequences of usually thick greywacke beds alternating with thin shale beds, which include sometimes intercalations of conglomerate beds. All the sedimentation of these flysch formations was controlled by tectonics. At the same time, should have occurred along with the first Hercynian deformation phase, a low-grade metamorphic event (chlorite zone), that affected these flysch deposits. This study highlights the influence of anisotropy and heterogeneity of these flysch rocks on their physical and mechanical characteristics. The anisotropy verified in some physical properties and on mechanical properties, due to the foliation makes difficult the sample preparation for the laboratory tests. Besides, it induces a scattering of the properties values measured, as for example, the strength and the deformability. The heterogeneity is related to the main features of these geological formations, which are constituted mostly by thinly stratified greywackes and shale beds, which sometimes may affect the results of the laboratory tests making them less representative. The study is made by using both shales and greywackes that constitute these flysch-type deposits in order to evaluate their geotechnical properties, mainly of the shales. Samples of these two rock materials, are tested accordingly a laboratory testing programme, which includes which included mineralogical analysis (X-ray diffraction), physical tests (bulk density, porosity, and void index) and mechanical tests (uniaxial compression, and deformability tests). Sat, 09 May 2015 23:00:00 GMT http://hdl.handle.net/10174/17370 2015-05-09T23:00:00Z http://hdl.handle.net/10174/17320 Title: Soil mineralogical composition effects on the durability of adobe blocks from the Huambo region, Angola Authors: Duarte, Isabel, M. R.; Pedro, Elsa, D. C.; Varum, Humberto; Mirão, José A. P.; Pinho, António B. Editors: Přikryl, Richard; Theodoridou, Magdalini; Török, Ákos; Gomez-Heras, Miguel Abstract: 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 used in the province of Huambo, especially by low-income families, which constitute the majority. This technique was established as an intangible heritage in the culture of that population. Huambo province is located in the central region of Angola (Central Plateau). Adobe blocks are building elements with potential degradation by the action of water. Due to the subtropical climate, hot and humid, and geomorphology of the province, located at about 1000–2000 m of altitude and with an extensive river system, these buildings can be vulnerable and may present premature degradation, exacerbated by the lack of knowledge concerning the properties of the geomaterials used and techniques/solutions that allow their stabilization and conservation. This paper aims to present the main results of the study to investigate the influence on adobe performance in regard to the mineralogy and geochemistry of soils used in the production of adobes used in the construction of dwellings. The knowledge gained with this research can support the development of solutions for the common anomalies and problems in this construction, as well as to improve the strength and durability of the adobe units. For this purpose, soil samples were collected and mineralogical, geochemical, and physical tests were performed. Durability and erodibility tests were also performed on selected adobes, following the Geelong method. The results obtained with this research may contribute to the development of the knowledge concerning this sustainable building solution, which has a strong presence in the province of Huambo and neighbouring regions. Tue, 13 Oct 2015 23:00:00 GMT http://hdl.handle.net/10174/17320 2015-10-13T23:00:00Z