Studies that are analysing new, environmentally friendly building materials are getting more attention in scientific community. This research is focused on hybrid geopolymer concrete (geopolymer with ordinary Portland-cement (OPC) additive) with aim to study strength development. In this article hybrid geopolymer concrete, manufactured using biomass bottom ash, fly ash and production waste of aluminium fluoride manufacturing (silica gel) with 4 different amounts of OPC (0%, 5%, 10% and 15%) is studied. Each blend is kept in 50 0C temperature and tested after 7, 14 and 28 days. The purpose of research was to study strength development in hybrid geopolymer concrete made from materials that are mentioned above
