The shrinkage of fly ash geopolymers was studied in the present study.Fly ash was used as the source material for making the geopolymers.The effects of the concentration of NaOH,sodium silicate-to-NaOH ratio,liquid-to...The shrinkage of fly ash geopolymers was studied in the present study.Fly ash was used as the source material for making the geopolymers.The effects of the concentration of NaOH,sodium silicate-to-NaOH ratio,liquid-to-ash ratio,curing temperature,and curing time on shrinkage were investigated.The geopolymers were cured at 25,40,and 60℃,respectively.The results indicate that the shrinkage of geopolymers is strongly dependent on curing temperature and liquid-to-ash ratio.The increase in shrinkage is associated with the low strength development of geopolymers.It is also found that NaOH concentration and sodium silicate-to-NaOH ratio also affect the shrinkage of geopolymers but to a lesser extent.展开更多
The electrical conductivity and dielectric property of fly ash geopolymer pastes in a frequency range of 100 Hz-10 MHz were studied.The effects of the liquid alkali solution to ash ratios（L/A） were analyzed.The mine...The electrical conductivity and dielectric property of fly ash geopolymer pastes in a frequency range of 100 Hz-10 MHz were studied.The effects of the liquid alkali solution to ash ratios（L/A） were analyzed.The mineralogical compositions and microstructures of fly ash geopolymer materials were also investigated using X-ray diffraction（XRD） and scanning electron microscopy（SEM）.The 10 mol sodium hydroxide solution and sodium silicate solution at a sodium silicate-to-sodium hydroxide ratio of 1.0 were used in making geopolymer pastes.The pastes were cured at 40℃.It is found that the electrical conductivity and dielectric constant are dependent on the frequency range and L/A ratios.The conductivity increases but the dielectric constant decreases with increasing frequency.展开更多
基金supported by the Thailand Research Fund through the Royal Golden Jubilee Ph.D. Program(No.PHD/0120/2549)
文摘The shrinkage of fly ash geopolymers was studied in the present study.Fly ash was used as the source material for making the geopolymers.The effects of the concentration of NaOH,sodium silicate-to-NaOH ratio,liquid-to-ash ratio,curing temperature,and curing time on shrinkage were investigated.The geopolymers were cured at 25,40,and 60℃,respectively.The results indicate that the shrinkage of geopolymers is strongly dependent on curing temperature and liquid-to-ash ratio.The increase in shrinkage is associated with the low strength development of geopolymers.It is also found that NaOH concentration and sodium silicate-to-NaOH ratio also affect the shrinkage of geopolymers but to a lesser extent.
基金supported by the Thailand Research Fund through the Royal Golden Jubilee Ph.D. Program(No.PHD/0359/2550)
文摘The electrical conductivity and dielectric property of fly ash geopolymer pastes in a frequency range of 100 Hz-10 MHz were studied.The effects of the liquid alkali solution to ash ratios（L/A） were analyzed.The mineralogical compositions and microstructures of fly ash geopolymer materials were also investigated using X-ray diffraction（XRD） and scanning electron microscopy（SEM）.The 10 mol sodium hydroxide solution and sodium silicate solution at a sodium silicate-to-sodium hydroxide ratio of 1.0 were used in making geopolymer pastes.The pastes were cured at 40℃.It is found that the electrical conductivity and dielectric constant are dependent on the frequency range and L/A ratios.The conductivity increases but the dielectric constant decreases with increasing frequency.
