TY - JOUR A1 - Falchi, L. A1 - Zendri, E. A1 - Müller, U. A1 - Fontana, Patrick T1 - The influence of water-repellent admixtures on the behaviour and the effectiveness of Portland limestone cement mortars N2 - Water-repellent mortars were prepared using different hydrophobic compounds as admixtures. Calcium and zinc stearates, silane/siloxane products (as liquid solution and powder) were mixed into limestone cement mortars for obtaining in-bulk water-repellent mortars suitable for building protection and resistant to the degrading action of water. The influences of the admixtures on the hydration and structure of the designed mortars were investigated by SEM, TG–DSC, FT-IR, XRD, and isothermal calorimetry. The effectiveness of these agents against water action was evaluated by using techniques and methods such as mercury intrusion porosimetry, water absorption tests and contact angle measurements. Siloxane products conveyed good water-repellent effectiveness, without strongly influencing the setting and hydration of the binder, while the zinc stearates slowed down the hydration reactions. KW - Water repellent admixtures KW - Portland limestone cement mortars KW - Hydration products KW - Pore size distribution KW - Siloxanes KW - Stearates PY - 2015 U6 - https://doi.org/10.1016/j.cemconcomp.2015.02.004 SN - 0958-9465 SN - 1873-393X VL - 59 SP - 107 EP - 118 PB - Elsevier Ltd. CY - Barking, Essex AN - OPUS4-33169 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falchi, L. A1 - Müller, U. A1 - Fontana, Patrick A1 - Balliana, E. A1 - Zendri, E. ED - Charola, A.E. ED - Rodrigues, J.D. T1 - Artificial weathering of water-repellent mortars suitable for restoration applications N2 - The study evaluates Portland limestone cement mortars, natural hydraulic lime mortars and pozzolan-lime mortars modified with water-repellent admixtures (metal soaps and siloxanes) for their use in the maintenance of historic buildings. The chemical-physical characteristics, the durability and the resistance to artificial weathering (exposure to UV light and artificial rain) were examined. The exposure conditions used in the ageing test were chosen in order to simulate outdoor environmental conditions, in particular the processes caused by UV-light and thermal shock induced by rain water. T2 - Hydrophobe VII - 7th International conference on water repellent treatment and protective surface technology for building materials CY - Lisbon, Portugal DA - 11.09.2014 KW - Water repellent admixtures KW - Mortars KW - Portland limestone cement KW - Natural hydraulic lime KW - Pozzolana-lime KW - Artificial weathering PY - 2014 SN - 978-972-49-2270-6 SP - 123 EP - 132 AN - OPUS4-32138 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falchi, L. A1 - Müller, Urs A1 - Fontana, Patrick A1 - Izzo, F.C. A1 - Balliana, E. A1 - Biscontin, G. A1 - Zendri, E. T1 - Sustainability in the maintenance and protection of architectural surfaces: Innovative water-repellent pozzolana-lime mortars N2 - Water-repellent renders were studied in order to evaluate their suitability for restoration applications. Water repellent admixtures, such as powdered siloxane-based products and metal soaps (zinc and calcium stearates), were mixed with a pozzolana-lime binder similar to historical binders with hydraulic properties. The chemical-physical and structural properties, the effectiveness and the durability of the water-repellent mortars in different environmental conditions were studied. The influence of the water repellent admixtures was evaluated by FT-IR analyses, by testing the mechanical properties and the behaviour in presence of water. The durability of the water-repellent mortars was evaluated after the exposure to artificial weathering (UV-light and water) and to immersion/drying cycles in saturated sodium sulphate solution. The nature of the water-repellent admixtures influenced both the hydration reactions and the chemical-physical properties of the mortars resulting in different resistance to the weathering and to salt crystallization. T2 - Scienza e beni culturali XXX. 2014 - Quale sostenibilita' per il Restauro? CY - Brixen, Italy DA - 01.07.2014 KW - Water-repellent admixtures KW - Artificial weathering KW - Salt crystallization KW - Restoration mortars PY - 2014 SN - 978-88-95409-18-4 SN - 2039-9790 SP - 637 EP - 648 PB - Edizioni Arcadia Ricerche S.r.l. AN - OPUS4-31841 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Falchi, L. A1 - Fontana, Patrick A1 - Izzo, F.C. A1 - Zendri, E. A1 - Mueller, U. T1 - Influence and effectiveness of water-repellent admixtures on pozzolana-lime mortars for restoration application N2 - Pozzolana–lime mortars modified with water-repellent admixtures were designed and studied to obtain mortars for restoration application. Powdered silane and calcium stearates were mixed with pozzolana, lime and sand and the chemical–physical properties of the resulting mortars were evaluated by X-ray diffraction, electron microscopy (SEM-EDX), thermogravimetric analysis and FT-IR spectroscopy. The mechanical behavior, the pore structure and the hygric behavior were measured. The resistance of water-repellent mortars to the salt crystallization was evaluated. Both calcium stearates and powdered silane allowed good water-repellent protection even if the water-repellent agents and their dosage modified some physical properties and the hydration kinetic. KW - Water-repellent admixtures KW - Pozzolana-lime mortars KW - Water absorption KW - Hydration KW - Stearates KW - Silane KW - Restoration PY - 2013 U6 - https://doi.org/10.1016/j.conbuildmat.2013.08.030 SN - 0950-0618 VL - 49 SP - 272 EP - 280 PB - Elsevier Science CY - Amsterdam AN - OPUS4-29940 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -