Geopolymer coating as a protection of concrete against chemical attack and corrosion Szymon Sikora, Ewa Gapys, Bartosz Michalowski, Tomasz Horbanowicz and Mariusz Hynowski E3S Web Conf., 49 (2018) 00101 Published online: 13 August 2018 DOI: 10.1051/e3sconf/20184900101