Details

Autor(en) / Beteiligte

• Rübner, Katrin
• Prinz, Carsten
• Adolphs, Jürgen
• Hempel, Simone
• Schnell, Alexander

Titel

Microstructural characterisation of lightweight granules made from masonry rubble

Ist Teil von

• Microporous and mesoporous materials, 2015-06, Vol.209, p.113-121

Ort / Verlag

Elsevier Inc

Erscheinungsjahr

2015

Link zum Volltext

Quelle

Elsevier ScienceDirect Journals Complete

Beschreibungen/Notizen

• [Display omitted] •Microstructure of lightweight granules made from masonry rubble depends on manufacturing method.•Thermal and hydrothermal granules consist of irregular pore networks containing non-uniform shaped pores.•Thermal granules have partly melted vitreous areas and macropores connected via narrow throats.•Hydrothermal granules have an accessible mesoporous system with plate-like and ink-bottle pores.•Water isotherms are sensitive to the nature and morphology of CSH in hydrothermal samples. 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.