Pengaruh Penggunaan Lumpur Sidoarjo sebagai Substitusi Material Fly Ash pada Geopolimer

Sari

The material of sidoarjo mud is generated from the volcano eruption of drilling gas in Porong, Sidoarjo, East Java, Indonesia. The material of sidoarjo mud was known as the cementitious material that was rich in content of Si and Al. Some studied were investigated to treat the material of sidoarjo mud by the calcination with high temperature. Yet, this investigation caused the consumption of energy, production time and increased production cost. The issue was a concern in this study so that did not use the calcination treatment in the production of sidoarjo mud. The results showed that the analysis of XRD indicated material of fly ash is
rich in quartz (SiO2), mullite (3Al2O3 2SIO2 or 2Al2O3 SiO2) dan hematite (Fe2O3), whereas the material of sidoarjo mud contained quartz (SiO2), mullite (3Al2O3 2SiO2 or 2Al2O3 SiO2), magnetite (Fe3O4), hematite (Fe2O3), and rutile (TiO2). Furthermore, the analysis of SEM showed that the particle of fly ash was amorphous and sphere with the misty surface. This surface of fly ash caused the absorption of an alkaline solution and reduced the workability in fresh mortar geopolymer. Also, the particle of sidoarjo mud was irregular agglomerate in shape with the rough surface. The shape of sidoarjo mud was considered not able to fill the concavity of binder, while the rough surface caused absorption of an alkaline solution in fresh geopolymer mortar. Use of sidoarjo mud as the binder in the geopolymer caused prolonged setting time and the highest compressive strength was about 19.1 MPa at the replacement of 10%.