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Roof coverings
Published in Derek Worthing, Nigel Dann, Roger Heath, of Houses, 2021
Derek Worthing, Nigel Dann, Roger Heath
Slate is a rock that was laid down in a series of thin beds. Large blocks of slate, which is a dense and very fine-grained material, are mined or quarried and then split by hand or machine to form sheets of the correct thickness. The blocks are easy to split due to the laminations which run along the lines of the original naturally occurring beds.
Dimension stones
Published in Francis P. Gudyanga, Minerals in Africa, 2020
Slate is a fine-grained, foliated, homogeneous metamorphic rock that is derived from an original shale-type sedimentary rock composed of clay or volcanic ash [1019]. It is frequently grey in colour, especially when seen, en masse, covering roofs but it also occurs in a variety of colours even from a single locality.
Pitched Roofs Classification
Published in Roy Chudley, Roger Greeno, Karl Kovac, Chudley and Greeno’s Building Construction Handbook, 2020
Roy Chudley, Roger Greeno, Karl Kovac
Slate is a natural dense material which can be split into thin sheets and cut to form a small unit covering suitable for pitched roofs in excess of 25° pitch. Slates are graded according to thickness and texture, the thinnest being known as ‘Bests’. These are of 4mm nominal thickness. Slates are laid to the same double lap principles as plain tiles. Ridges and hips are normally covered with half round or angular tiles whereas valley junctions are usually of mitred slates over soakers. Unlike plain tiles, every course is fixed to the battens by head or centre nailing.
Sediment provenance in the Murchison and Maruia basins, Aotearoa/New Zealand: a record of Neogene strike-slip displacement, convergence, and basement exhumation along the Australian–Pacific plate boundary
Published in New Zealand Journal of Geology and Geophysics, 2022
Matthew W. Sagar, Karen E. Higgs, Dominic P. Strogen, Kyle J. Bland, Greg H. Browne
Sandstone from the western Murchison Basin is arkosic, with Q, F and R ranging from 38% to 63%, 31% to 45%, and 3% to 24%, respectively. All except two samples, which are from the late Eocene Maruia Formation, plot in the arkose field (Figure 2A). The two late Eocene samples contain more rock fragments (c. 20% vs. c. 5%–10%), and plot in the lithic arkose field (Figure 2A; Table 4). Proportions of rock fragment types vary widely, although all samples have >30% RmRmis (Figure 2C). Metamorphic rock fragments (mostly slate and schist, rare quartzite) are particularly abundant in two samples (P91818, 55%; P79921, 86%). In some samples RsRmis (e.g. P79916, 64%) and/or RiRmis (e.g. P81113, 27%) dominate but others contain subequal proportions of each major type (e.g. sample P79925). All late Eocene–middle Miocene samples analysed using the Folk method have ratios of plutonic to volcanic lithics (Rp/Rv) >> 1.00 (5.03–15.0). On the QmKP diagram, however, all the western Murchison Basin samples form a relatively tight cluster (Figure 2B). Total mica is <10% and biotite is predominant (btM = 44–100%) in all samples. Muscovite is common in some samples (muM = c. 30%–40%) and minor chlorite was observed in only three samples (chlM < 25%).
Processing of electric ceramic insulators from slate rocks and MgO
Published in Materials and Manufacturing Processes, 2020
S. M. Naga, M. Sayed, M. M. El-Omla, Ahmed R. Wassel, N. El-Mehalawy
In the current study, ceramic bodies enriched with cordierite were fabricated using naturally occurring slate rocks. Slate is tenderized metamorphic rock with a moderately high degree of schistosity. Its color ranges between green, gray and red. Its mineral constituents are rearranged based on the type of stress applied to the rock. The minerals can be squeezed, stretched and rotated to align in a given direction. Slate is mainly composed of alumina and silica, and it is a soft rock that can be crushed to produce an extremely fine powder. It is composed of calcite, quartz, muscovite, talc, albite and chlorite. Slate rock possesses an abundance of fine-grained sheet-like silicates, giving the rock a greasy feel and discriminatory cleavage, which causes the rocks to facilely break into slender sheets.[22,23] Slate is a material of great geological multitude that is present in the Eastern Desert and the Sinai Peninsula. It is a cheap material serviceable for application in the ceramic industries. The present study aims to determine the usability of slate rock as a cheap local starting aluminum silicate material for the production of ceramic bodies enriched with cordierite. The effect of partially replacing slate with MgO on the physical, microstructure, mechanical properties, thermal expansion coefficient and dielectric behavior of the fabricated sintered bodies employed as electrical insulators was evaluated.
Effect of bedding angle on tunnel slate failure behavior under indirect tension
Published in Geomatics, Natural Hazards and Risk, 2020
Han Wang, Fuqiang Ren, Yuan Chang
At present, there are many experimental studies on rock anisotropy, including uniaxial (Dubey and Gairola 2000; Egli 2006), conventional triaxial (Li et al. 2012), true triaxial compression (Nguyen and Le 2015), Brazilian splitting (Tavallali et al. 2007; Tavallai and Vervoort 2010), hydraulic fracturing (Lin et al. 2016; Zhuang et al. 2019), and others. Lithology mainly involves sandstone, shale, schist, and slate (Chandler et al. 2016; Bonnelye et al. 2017). The anisotropic characteristics of different structural plane angles are analyzed in terms of mechanical parameters, failure modes, and crack morphology. Among the mechanical behaviours of anisotropic rocks, tensile behaviour is very important for engineering practice. Most disasters are caused by insufficient tensile strength of rocks (Ye et al. 2014). Tensile strength parameters of a rock can be obtained by two main ways: direct and indirect tension. In most cases, it is difficult to prepare a sample for direct tension test (Feng and Xia 2010). Therefore, indirect tension is the main way to evaluate the tensile mechanical behaviour of rock.