Pengaruh Penambahan -Al2O3 pada Homogenitas Matriks Geopolimer Andi Indra Wulan Sari Ramadani, Abdul Haris, Subaer Subaer

Abstract

A study has been conducted on microstructure of geopolymers added with y-Al2O3. Precursor used was metakaolin which produced through dehydroxilation of kaolin at 750⁰ C for 6 hours. y-Al2O3 mineral was extracted from metakaolin using a procedure developed in this study. The aims of this study was to investigate the morphology and the homogeneity of geopolymer matrix with and without the addition y-Al2O3. Geopolymers were synthesized by using alkali activation of metakaolin. y-Al2O3 mineral was poured into geopolymer paste, stirred gently until the mixture homogenous followed by curing at 60⁰ C for 1 hour. X-Ray Diffraction characterization was used to examine the phase of kaolin, metakaolin, y-Al2O3, and geopolymer produced. The results showed that the extraction procedure were able to produced 7 - 12 wt% of y-Al2O3 mineral. Geopolymers sample produced and aged 28 days were characterized using SEM-EDS. The results showed the matrix of samples with y-Al2O3 was more homogenous that those without y-Al2O3. These results are expected to have positive correlation with physical and mechanical properties of geopolymers.