TY - JOUR A1 - Rübner, Katrin A1 - Prinz, Carsten A1 - Adolphs, Jürgen A1 - Hempel, S. A1 - Schnell, A. T1 - Microstructural characterisation of lightweight granules made from masonry rubble N2 - 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. KW - Lightweight aggregates KW - Construction and demolition waste KW - Mercury porosimetry KW - Nitrogen sorption KW - Water vapour sorption PY - 2015 U6 - https://doi.org/10.1016/j.micromeso.2014.08.060 SN - 1387-1811 SN - 1873-3093 VL - 209 SP - 113 EP - 121 PB - Elsevier Inc. CY - Amsterdam AN - OPUS4-32139 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -