Sodium Sebagai Aktivator Fly Ash, Trass Dan Lumpur Sidoarjo Dalam Beton Geopolimer

. Some previous studies showed that the compressive strength of geopolymer concrete was dependent on pozzolanic materials used and the concentration of activator solution in the mixture. The effort to use Sidoarjo Mud and trass as an additive material in the mixture was investigated in this study to analyze the mechanical properties of the concrete. NaOH solution mixed with Na2SiO3 was used as the activator solution varied from 8 M to 14 M. Ratio of Na2SiO3 to NaOH solution by mass were also varied from 0.5 to 2.5 Trass and Sidoarjo Mud were introduced as fly ash substitution in the mixture. Compressive strength test of cylindrical specimens, splitting test and porosity test were carried out comprehensively to compare the specimens from each composition. The results showed that the strength of geopolymer concrete was influenced by the concentration of NaOH solution and the ratio of Na2SiO3 to NaOH in the alkali solution and the composition of the binder