Microstructural characterisation of lightweight granules made from masonry rubble

Autor: Carsten Prinz, Katrin Rübner, Jürgen Adolphs, Simone Hempel, Alexander Schnell
Rok vydání: 2015
Předmět:
Zdroj: Microporous and Mesoporous Materials. 209:113-121
ISSN: 1387-1811
DOI: 10.1016/j.micromeso.2014.08.060
Popis: The pore structure of lightweight granules made from masonry rubble was studied in order to better understand their engineering properties. Thermally and hydrothermally hardened granules were tested. Analysis by ESEM, mercury porosimetry and sorption methods yield important insight into their microstructure. The thermal granules are characterised by partly melted vitreous areas and large internal macropores that are connected via narrow throats. They show a marginal specific surface area along with a hydrophobic behaviour. In contrast, the hydrothermal granules have an accessible mesoporous system containing plate-like and ink-bottle pores. The shape of their water isotherms depending on the granules’ CaO content is sensitive to the morphology of calcium silicate hydrate phases (CSH). The hysteresis changes from a narrow loop that closes at low pressures, which can be attributed to coarser more crystalline CSH, to a large triangular-shaped loop along with a low pressure hysteresis, which is characteristic for fine fibre-like CSH with ink-bottle and plate-like pore morphologies. Granules with fibre-like CSH have the higher specific surfaces areas but those with more crystalline CSH show stronger physisorption of water molecules.
Databáze: OpenAIRE