TY - JOUR A1 - Kargol, Marta A1 - Müller, Urs A1 - Gardei, André T1 - Properties and performance of silane: blended cement systems N2 - The paper presents the results of a study dealing with the performance of water repellents on hardened blended cement pastes. Since on the European market Portland cement does not play the dominant role anymore and due to the new national and European policies concerning Greenhouse Gases and sustainability, cement manufacturers produce more and more blended cements (CEM II–CEM V). Nevertheless, the majority of experience concerning the efficacy of water repellents is gained from Portland cement; therefore knowledge in regard to the interactions of blended cement with water repellent agent is minimal. Two silane-based products were applied on 'fresh' and carbonated cement substrates containing limestone, fly ash, slag and trass, and were investigated in terms of their functionality. The evaluation of the treatments' performance and effectiveness were assessed using various laboratory measurements. Hydrophobicity, water absorption, colour changes and the penetration depth of silanes into the substrate were evaluated before and after artificial aging experiments. Moreover, the outdoor weathering test was performed to shed light on treated surface appearance in a 'real' outdoor environment. The results showed that surface wettability was independent on water ingress or colour variations, especially for cement specimens artificially aged by accelerated carbonation. Cement pastes containing slag and trass seemed to more distinctly affect the water repellents' surface performance. KW - Water repellents KW - Silanes KW - Impregnation KW - Aging KW - Carbonation KW - Durability KW - Blended cement KW - Fly ash KW - Hydrophobicity KW - Hydrophobic agent PY - 2013 U6 - https://doi.org/10.1617/s11527-012-9984-1 SN - 1359-5997 SN - 1871-6873 VL - 46 IS - 9 SP - 1429 EP - 1439 PB - Springer CY - Dordrecht AN - OPUS4-31839 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -