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Abstract: The present study propounds development of an artificial sand, with a prime aim of exploring a potential substitute for natural river sand. The artificial sand, named F-Slag sand, within the particle size range of 4.75 − 0.075 mm, is developed with the combined use of fly ash (FA) and ground granulated blast furnace slag (GGBS) as binder solids (BS) blended in proportions of 90:10, 80:20, 70:30, 60:40, and 50:50. Pelletization, by employing a custom designed disc pelletizer equipment, and geopolymerization, a process of binding and bonding of FA and GGBS particles to form sand size fractions, techniques are adopted to synthesize F-slag sand. Pelletizer speed of 15 rpm, pelletization duration of 10 min, and alkali activator solution to BS ratio of 0.06 are found optimal to produce the sand. A comprehensive micro/meso-analysis, including 3D computed tomography scan, scanning electron microscopy, X-ray diffraction, Brunauer-Emmett-Teller analysis, and Fourier transform infrared spectroscopy are performed on F-slag sand and attempts are made to interpret macro-applications of it. Demonstrably, the synergistic use of GGBS and FA has completely alleviated the need for elevated curing of sand. The gradational analysis revealed that more than 90% of BS are converted into sand size fractions (4.75 − 0.075 mm). F-slag sand exhibited specific gravity of 2.1, water absorption of 17%, permeability 4.2 × 10− 3 cm/sec, angle of internal friction of 38°, and crushing value of 14.8%. In comparison, river sand showed 2.6, 4%, 3.6 × 10− 3 cm/sec, 39° and 6.3% respectively. The loose and compacted bulk densities of F-slag sand are measured at 698 and 991 kg/m3, which are significantly lower vis-à-vis of river sand (1546 and 1728 kg/m3). Micro-analysis confirms dense, well-bonded particles with meso–macroporous connectivity, indicating enhanced mechanical stability and durability. Moreover, leaching and environmental risk analysis affirms that F-Slag sand poses no ecological threat. The outcome of the study, proposition of a novel construction material, elucidates that F-slag sand could be a potential substitute for river sand in building (concrete, mortar, plastering, lightweight structures), mining (mine backfilling) and environmental (drainage & filter) applications.
Keywords: F-Slag sand, geopolymer-assisted pelletization, artificial fine aggregates, fly ash-slag synergy, micro-meso scale characterization, disc pelletizer
Published in DiRROS: 23.06.2026; Views: 201; Downloads: 196
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Abstract: V goslarski delavnici "Atelje Demšar" smo dobili štiri vzorce lesa za godalne loke tujih dobaviteljev, ki so jih označili z imeni (1) pernambuk, (2) konjskomeso, (3) brazil in (4) kačji les. Les smo anatomsko preiskali ter določili vrste: (1) Guilandina echinata (pernambuk, pau brazil, brazil), (2) Manilkara bidentata (massaranduba, konjsko meso), (3) Shorea laevis (balau, bangkirai), (4) Brosimum guianense syn. Piratinera guianensis (Schlangenholz, snakewood, kačji les). Identifikacija je v treh (1, 2 in 4) od štirih primerovpotrdila lesno vrsto, kot jo je navedel dobavitelj lesa. Preiskane lesne vrste pernambuk, konjsko meso in kačji les (1, 2 in 4) iz južne Amerike imajo skupne naslednje lastnosti: fino teksturo, temno obarvano jedrovino, dekorativen videz, visoko gostoto, visoko trdnost, dobro dimenzijsko stabilnost in dobre obdelavnostne lastnosti, posebno struženje in površinsko obdelavo. Vse so zelo cenjene za godalne loke, za najboljšega pa velja les pernambuka. Les balau iz Azije ima slabše lastnosti in ni tipična lesna vrsta za loke. Razlike v zgradbi lesa preiskanih vrst so najverjetneje vzrok za razlike v kvaliteti končnega izdelka. Podajamo opis izdelave lesenega loka, opis lesnih lastnosti in pomen pravilne identifikacije in poimenovanja lesa.
Keywords: godalni lok, pernambuk, Guilandina echinata syn. Caesalpina echinata, massaranduba syn., konjsko meso, Manilkara bidentata, kačji les, Brosimum guianense syn. Piratinera guianensis, balau, Shorea laevis, anatomija lesa
Published in DiRROS: 12.07.2017; Views: 6691; Downloads: 2619
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Keywords: prašiči, meso, prašičja stegna, kraški pršut, hlapne spojine, določanje, ocenjevanje
Published in DiRROS: 11.07.2017; Views: 6319; Downloads: 1705
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Keywords: govedoreja, prireja, mleko, 110 let, meso, kontrola, rezultati, 2013, Slovenija, poročila
Published in DiRROS: 03.06.2015; Views: 8117; Downloads: 2244
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