Characterization of Geopolymer Binder Using Sidoarjo Mud

Sidoarjo mudflow (SM) is a new cementitious material originating from a natural disaster of volcano mudflow in Porong, Sidoarjo, East Java, Indonesia. Some investigations mentioned that the material of SM is rich in Si, Fe, Al and Ca content. The content of Si and Al were considered to be able to generate the gel of Si-O-Si and Si-O-Al in the geopolymer binder. However, the feasibility of SM material as an alternative binder in geopolymer still needs to be investigated in this study. The production of SM material was calcined at the temperature of 400°C up to 900°C which the optimum calcination temperature was about 700°C. This material was called as volcano meta ash (VMA). The analysis of XRD showed that the geopolymer binder of VMA, FA_VMA, and FA had the crystalline in quartz, mullite, magnetite, hematite, and rutile. The analysis of FTIR described that the geopolymer binder of VMA and FA_VMA had similar stretching in the gel of Si-O-Si and Si-O-Al to the geopolymer binder of FA. However, the stretching and bending of H-O-H in the geopolymer binder of VMA and FA_VMA were less than the geopolymer binder of FA. Finally, the analysis of SEM showed that the geopolymer binder of VMA has less concavity and more gel compared to the geopolymer of FA_VMA and FA.