掺粉煤灰水泥砂浆吸波性能的研究

Research on Cement-based Fly Ash for Wave-absorbing Properties

为了研究粉煤灰在建筑材料中的吸波性能,将Ⅲ级粉煤灰掺入水泥砂浆中,制成了厚度为10-30 mm,长宽为180 mm×180 mm的试样,在水中养护8个月后进行吸波性能的测试。测试结果显示：粉煤灰在高频区具有一定吸波性能,随试样厚度的增加,这种吸波性能逐渐提高,在16.2 GHz处,最大吸收率可达14.5 dB;粉煤灰掺量为45%的水泥砂浆,大于6 dB吸收峰累计带宽超过10 GHz,在10-18 GHz范围内吸收率全部大于6 dB,且随频率的增加,吸波性能增加;粉煤灰掺量15%、厚度为15 mm、25 mm的水泥砂浆,大于6 dB吸收峰累计带宽超过9 GHz,在10-18 GHz范围内吸收率全部大于6 dB。粉煤灰在电磁防护领域具有潜在的应用价值。

In order to research the wave-absorbing properties of fly ash in building materials, Type Ⅲ fly ash was added in mortar at the thickness of 10-30 mm. After cured for 8 months, wave-absorbing properties were researched with the arched testing method. The results show that fly ash has a maximum absorption 14.5 dB at 16.2 GHz. For mortar with 45 % fly ash, the bandwidth for 6 dB is over 10 GHz,and in 10-18 GHz frequency range, all absorptions are more than 6 dB, and absorptions increase as frequency increases. Mortars with 15% fly ash at thickness of 15 mm and 25 mm have optimal absorption; bandwidth for 6 dB is over 9 GHz. A high potential application of fly ash in electromagnetic protection is expected.