Preparation and characterization of geopolymer concrete made of natural zeolite by heating method

The addition of Lampung - Indonesia natural zeolite material as an added material for the manufacture of geopolymer concrete has been carried out. Geopolymer is made by heating at various temperatures of 50, 70, 110, and 130°C with holding times of 6, 9, and 12 hrs. Analysis of chemical composition using x-ray fluorescence while the crystal phase using x-ray diffraction. The mechanical properties to determine the compressive strength of geopolymer concrete. While the physical properties in terms of density. The test results obtained the highest compressive strength of 13.53 Mpa from 130°C with a holding time of 6 hrs. The density of geopolymer concrete is between 1.255 to 1.874 kg/mm3, which is influenced by the composition of the concrete forming material. Lampung natural zeolite with a dominant composition of 67.15% SiO2 and 13.19% Al2°3 is very suitable to be used as a substitute for cement in geopolymer concrete. The crystalline phases formed in all concrete are quartz and albite. While at temperature variations, there are other crystalline phases. These different crystalline phases are influenced by the K, Na, Al, and Si bonds formed.