Uji Triaksial Unconsolidated Undrained Pada Tanah Lanau yang Distabilisasi Geopolimer Fly Ash dan Bubuk Cangkang Telur

Soil is an essential component in construction and related to the buildings built on it. The problem is that not all soils have adequate bearing capacity. Therefore, it is necessary to improve soil by using the geopolymer stabilization method utilizing environmentally friendly waste, namely, fly ash (FA) and eggshell powder (ESP). Alkali activator used is sodium silicate (Na2SiO3) and sodium hydroxide (NaOH) in a ratio of 50:50 with a molarity of five molars and ten molars. The test carried out in this study is the unconsolidated undrained (UU) triaxial test. The purpose of this study was to determine the effect of alkali activator molarity, curing age, and the substitution of FA with eggshell powder on the value of the shear strength parameter. From the test results, the shear strength of the mixture with a ten molar content of 20% FA has a greater value than the mixture with five molar content. Furthermore, the five molar content of 5% ESP at seven days of curing had a greater cohesion value than the five molar 20% FA mixture. The result indicates that the greater the molarity of the alkaline activator and the substitution of FA with eggshell powder, the higher the shear strength of the soil.