doiSerbia

Compressive strength and hydrolytic stability of fly ash based geopolymers

Nikolić Irena (University of Montenegro, Faculty of Metallurgy and Technology, Podgorica, Montenegro)
Đurović Dijana (Institute of Public Health of Montenegro, Podgorica, Montenegro)
Zejak Radomir (University of Montenegro, Faculty of Civil Engineering, Podgorica, Montenegro)
Karanović Ljiljana (Laboratory of Crystallography, Faculty of Mining and Geology, Belgrade)
Tadić Milena (University of Montenegro, Faculty of Metallurgy and Technology, Podgorica, Montenegro)
Blečić Dragoljub (University of Montenegro, Faculty of Metallurgy and Technology, Podgorica, Montenegro)
Radmilović Velimir R. (Faculty of Technology and Metallurgy, Belgrade)

The process of geopolymerization involves the reaction of solid aluminosilicate materials with highly alkaline silicate solution yielding an aluminosilicate inorganic polymer named geopolymer, which may be successfully applied in civil engineering as a replacement for cement. In this paper we have investigated the influence of synthesis parameters: solid to liquid ratio, NaOH concentration and the ratio of Na2SiO3/NaOH, on the mechanical properties and hydrolytic stability of fly ash based geopolymers in distilled water, sea water and simulated acid rain. The highest value of compressive strength was obtained using 10 mol dm-3 NaOH and at the Na2SiO3/NaOH ratio of 1.5. Moreover, the results have shown that mechanical properties of fly ash based geopolymers are in correlation with their hydrolytic stability. Factors that increase the compressive strength also increase the hydrolytic stability of fly ash based geopolymers. The best hydrolytic stability of fly ash based geopolymers was shown in sea water while the lowest stability was recorded in simulated acid rain.

Keywords: geopolymerization, fly ash, compressive strength, hydrolytic stability

Projekat Ministarstva nauke Republike Srbije, br. 172054 i Nanotechnology and Functional Materials Center, funded by the European FP7 project No. 245916