Characterization of Fresh Sidoarjo Mud as Material on Geopolymer System

Abstract

Sidoarjo mud is the alternative cementitious material which derived from a volcano mud eruption in Porong, Sidoarjo, East Java, Indonesia. The calcination of fresh sidoarjo mud in high temperature was known rich in the content of Si and Al that has similar chemical content with the material of OPC. However, the calcination process had caused the consumption of energy, time duration and cost in the production. To solve the problem, this study was required to investigate the fresh sidoarjo mud without the calcination process. However, material of FSM was analyzed to understand its feasibility as a material in geopolymer referring to the material of fly ash. The results showed that the material of FA consisted of quartz (SiO2), mullite (3Al2O3 2SiO2 or 2Al2O3 SiO2) and hematite. While, the material of FSM consisted of quartz (SiO2), mullite (3Al2O3 2SiO2 or 2Al2O3 SiO2), magnetite (Fe3O4), hematite (Fe2O3), and rutile (TiO2). The particle of FA was amorphous and sphere with the misty surface that caused the absorption of alkaline solution and reduced the workability on fresh geopolymer mortar. While the particle of FSM was the agglomerate irregular shape with the rough surface that also caused the absorption of alkaline solution and reduced the workability on fresh geopolymer mortar. The analysis of FTIR identified that the material FA and FSM had the stretching in the gel of Si-O-Al and Si-O-Si. The compressive strength reached optimum at the replacement of 5% FSM.