On Production of Pre-Formed Foamed Geopolymer Concrete

This investigation presents the potential of producing of pre-formed foamed geopolymer concrete. Waste material such as fly ash as a cementitious material was mixed with an alkaline activator solution (a mixture of sodium silicate and sodium hydroxide), then pre-formed foam was added to the geopolymer mixture to produce lightweight concrete. Four foamed geopolymer concrete mixes with density of 1500 kg/m3 in addition to foamed concrete mix as a reference were produce and their compressive strength were investigated. The main purpose of this paper is to investigate the potential of producing pre-formed foamed geopolymer concrete and to examine the effect of sodium silicate solution to sodium hydroxide solution (SS/SH) ratio. It was noticed that a white powder (sodium carbonate) appeared on the concrete surface when the ratio of (SS/SH) equals to 0.4, while it does not with ratio of 1.75. The appearance of their white powder led to get low strength about 10% of the mix with no white powder when (SS/SH) equals 1.75.