关键词: 半干法脱硫灰, 蒸压加气混凝土, 力学性能, 孔隙率, 水化产物

Abstract: Autoclaved aerated concrete was prepared by semi dry desulfurization ash，and the effects of different desulfurization ash content on the compressive strength，dry density and water absorption of aerated concrete were studied.Through the image processing functions of MATLAB and IMAGE J，the changes of porosity and the relationship between pore diameter and occurrence frequency were studied.Finally，the hydration products were analyzed by Xray diffraction (XRD) and scanning electron microscope (SEM).The results showed that with the increase of desulfurization ash content，the compressive strength and dry density of autoclaved aerated concrete first increase and then decrease，while the porosity and water absorption first decrease and then increase.For the pore structure，with the increase of desulfurization ash content，the frequency of pores from 14 μm to 5.4 μm first decreased and then increased，and the frequency of pores greater than 67 μm gradually increased.XRD and SEM results show that the appropriate amount of desulfurization ash is conducive to the formation of tobermorite，enhancing the crystallinity of tobermorite，making the spatial distribution of tobermorite more compact，and improving the mechanical properties of autoclaved aerated concrete.The results show that the autoclaved aerated concrete prepared with 10% to 20% desulfurization ash can meet the performance index requirements of A3.5B06 autoclaved aerated concrete.

Key words: semi dry desulfurization ash, autoclaved aerated concrete, mechanical properties, porosity rate, hydration products