高铁粉煤灰对水泥基材料吸波特性的影响

Influence of high-iron fly ash on Absorption property of cement based materials

采用X射线衍射(XRD)、扫描电子显微镜(SEM)、能量色散谱仪(EDS)分析粉煤灰中铁组分矿物组成和分布形态,对高铁粉煤灰颗粒电磁参数及复合高铁粉煤灰水泥浆体的吸波性能进行了试验研究。结果表明,粉煤灰中富集在球形颗粒表面的各种微细氧化铁晶体,是高铁粉煤灰产生电磁损耗的物质基础;高铁粉煤灰颗粒具有较高的介电常数和一定的磁导率,是以介电损耗型为主的电磁波有效损耗介质;高铁粉煤灰水泥基复合材料在2～8GHz波段范围内具有吸波性能,其最小反射率为-13.01dB,同时吸波能力可能与材料电导率有关。

Based on the analysis of composition and form for the iron components in fly ash by X-ray diffraction （XRD）, scanning electron microscope（SEM）,energy dispersive spectrometer（EDS）, the electromagnetic parameters of fly ash particles and the wave absorbing properties of high-iron fly ash grout were studied with experi- ments. The results showed that： （1） A variety of fine iron oxide crystals enriched in the spherical surface of fly ash particles play an important role in electromagnetic loss; （2） the high-iron fly ash particles have a higher com- plex permittivity and a certain degree of permeability and are electromagnetic loss media characterized by dielectric loss; and （3） high-iron fly ash cement-based composite materials has obvious wave absorbing properties with the minimum reflectivity --13.01dB in the frequency 2-8GHz, however, the wave absorbing capacity of cement-based composite rely on the conductivity of the material.