The dolomite waste from industry especially quarry increased every year in Malaysia and worldwide. Dolomite basically is waste obtained from the decorative stone industry, cement industry and dolomite industry itself. The main objective of this study was to investigate the utilization of dolomite as alkali activated specially in geopolymers synthesis. Based on the records, there has been no study yet on dolomite as main source (60% to 100%) for alkali activated or geopolymer. These need meticulous investigations in order to be used widely through technically viable for highly performance of cements in construction industry. This study has been conducted to produce alkali activated dolomite and dolomite/fly ash geopolymer and bricks using the geopolymerization process. Fly ash was found to improve the reactivity and strength of the geopolymer. Fly ash was incorporated as replacement of filler due to the low reaction of dolomite after initial investigation on this study. The parameter used to find the optimum mix design of geopolymer paste production include the NaOH concentrations, ratios of solid to liquid (S/L) as well as sodium silicate to sodium hydroxide (Na2SiO3/NaOH) ratios. The properties of all the geopolymer were evaluated using compressive strength, X-Ray diffraction (XRD), scanning electron microscope (SEM), and Fourier transform infrared (FTIR). Meanwhile, for mix design of dolomite/fly ash geopolymer bricks, the best optimum mix design for the dolomite/fly ash (D/FA) geopolymer was used along with the dolomite/fly ash ration while the raw materials to sand ratio for bricks used was 1:3. The performance of the alkali activated D/FA bricks were analyzed in term of compressive strength, water absorption, and resistivity towards high temperature exposure. From this study the optimum compressive strength was achieved at NaOH concentration 22M, ration of S/L at 2.5, and Na2SiO3/NaOH ratio at 2.5. From the phase characterization using XRD, the existence of C-A-S-H peak were obtained from alkali activated dolomite and C-A-S-H + N-A-S-H peak for D/FA geopolymer which determined the existence of geopolymer gel through geopolymerization process. The strength of the D/FA geopolymer obtained in this study is also high and suitable to beused for construction applications. The density of all the D/FA geopolymer can also be classified into lightweight according to ASTM C55-11. Besides that, for bricks produced using D/FA, showed and increment in strength with the decreasing of D/FA ratio where the maximum strength was up to 61.24 MPa. As for the water absorption for the D/FA bricks, the range was 6.89% to 10.34% which less than the limit of (17%) of ASTM C90 specification. The D/FA bricks were also found to be able to withstand temperature up to 1000C but had undergone a change in its strength. Based on the study, D/FA bricks were considered to have better properties and manufacturing process compared to the OPC bricks.
