TY - JOUR N2 - This paper presents an experimental investigation on the mechanical properties and microstructure of geopolymer repair materials mixed using fly ash (FA) and concrete substrates. An optimal combination of FA and concrete substrate was determined using the compressive test of geopolymer mortar mixed with various concrete substrate classes. It was found that the contribution of (C35/45) concrete substrates with the FA geopolymer mortar increases the 28-day bonding strength by 25.74 MPa. The microstructure analysis of the samples using scanning electron microscopy showed the denser structure owing to the availability of high calcium and iron elements distribution. These metal cations (Ca2+ and Fe3+) are available at OPC concrete substrate as a result from the hydration process reacted with alumina-silica sources of FA and formed calcium aluminate silicate hydrate (C-A-S-H) gels and Fe-bonding linkages. L1 - http://www.journals.pan.pl/Content/125061/PDF-MASTER/AMM-2022-4-10-Al%20Bakri.pdf L2 - http://www.journals.pan.pl/Content/125061 PY - 2022 IS - No 4 EP - 1281 DO - 10.24425/amm.2022.141052 KW - fly ash geopolymer KW - repair material KW - concrete substrate KW - interfacial zone transition A1 - Al Bakri Abdullah, Mohd Mustafa A1 - Aziz, Ikmal Hakem A. A1 - Zailani, Warid Wazien Ahmad A1 - Rahim, Shayfull Zamree Abd A1 - Yong, Heah Cheng A1 - Sandu, Andrei Victor A1 - Peng, Loke Siu PB - Institute of Metallurgy and Materials Science of Polish Academy of Sciences PB - Committee of Materials Engineering and Metallurgy of Polish Academy of Sciences VL - vol. 67 DA - 2022.11.23 T1 - Silica Bonding Reaction on Fly Ash Based Geopolymer Repair Material System with Incorporation of Various Concrete Substrates SP - 1277 UR - http://www.journals.pan.pl/dlibra/publication/edition/125061 T2 - Archives of Metallurgy and Materials ER -