DSpace Collection:http://hdl.handle.net/10174/143912024-03-28T12:15:29Z2024-03-28T12:15:29ZInfluence of anisotropy on the mechanical properties of Baixo Alentejo flysch rocks (Portugal)Pinho, António B.Duarte, Isabel M.R.Rosa, Francisco R.S.Rodrigues-Carvalho, José A.http://hdl.handle.net/10174/173702016-02-17T10:34:53Z2015-05-09T23:00:00ZTitle: 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).2015-05-09T23:00:00ZSoil mineralogical composition effects on the durability of adobe blocks from the Huambo region, AngolaDuarte, Isabel, M. R.Pedro, Elsa, D. C.Varum, HumbertoMirão, José A. P.Pinho, António B.http://hdl.handle.net/10174/173202016-02-15T12:22:34Z2015-10-13T23:00:00ZTitle: 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.2015-10-13T23:00:00Z