粉煤灰基地质聚合物发泡材料的性能与微观结构

本研究以循环流化床粉煤灰(CFA)、水玻璃(WG)和氢氧化钠(NaOH)为原料,双氧水(H₂O₂)为化学发泡剂,制备粉煤灰基地质聚合物发泡材料。通过添加掺量(wt)3%～8%的H₂O₂发泡剂,测试发泡材料的发泡倍数、孔径分布、表观密度、宏观孔隙率和抗压强度等物理和力学性能,研究该体系的发泡驱动力与浆体阻力的平衡点和宏观孔结构对抗压强度的影响。结果表明:掺量(wt)5%是该体系发泡驱动力与浆体阻力的平衡点;当H₂O₂发泡剂掺量(wt)为5%时,发泡倍数、表观密度、宏观孔隙率和抗压强度分别为4.2倍、255 kg/m3、81.7%和0.65 MPa。不同的孔径分布对抗压强度的影响程度是不同的,其中孔径10～20μm的孔为关键因子,对抗压强度影响最大。

Microstructure and properties of coal-fly-ash-based foam geopolymer

Large amount of circulating fluidized bed combustion fly ash (CFA) were generated in power plants.In this paper,foam geopolymer material was prepared using CFA,water glass (WG) and sodium hydroxide (NaOH) as raw material and hydrogen peroxide as foaming agent.By adopting (wt) 3%-8% hydrogen peroxide,the properties of foaming multiple,pore size distribution,apparent density,macro porosity and compressive strength were tested.The balance of foaming driving force and paste resistance and the influence of macro pore structure on compressive strength were studied.The results showed that the balance of the foaming driving force and paste resistance was content of H₂O₂ (wt) of 5%； and the foaming multiple,apparent density,macro porosity and compressive strength were 4.2,255 kg/m3,81.7% and 0.65 MPa respectively when the H₂O₂ foaming agent(wt) was 5%.The different pore size distribution had different degree of the decrease on compressive strength,the gray correlation degree between compressive strength of samples and pore diameter range of 10-20 μm was the greatest,that was,the range of pore size was 10-20 μm as the key factor,and the effect on compressive strength of samples was the largest.