电阻率法研究大掺量粉煤灰净浆的吸附效应

Research on Adsorption Effect of High Volume Fly Ash Paste Using Electrical Resistivity Method

为了研究粉煤灰的吸附效应,采用电阻率法记录了粉煤灰不同掺量净浆电阻率发展曲线,并用2种对比样品进行验证以及净浆抗压强度分析。结果表明,粉煤灰颗粒中表面氧化物,特别是未燃尽碳粉对液相中金属离子的吸附作用使得水胶比0.5的样品FA含量<40%时曲线与含量≥40%的不同,粉煤灰掺量≥40%时电阻率发展曲线在最低点之前有一奇异极小值点;随着粉煤灰掺量增大,电阻率曲线早期较高而后期较低,且曲线最低点延迟,最低点对应的电阻率值增大。

In order to study the adsorption effect of fly ash, electrical resistivity method was used to record electrical resistivity curve development of the pastes incorporated with various contents of fly ash, and two contrast samples were used to confirm the conclusion, as well as compressive strength. The results show, the adsorption of the oxides in the fly ash particles, especially un-burned carbon powders on metal ions in the liquid solution leads to that the electrical risistivity of the pastes with FA contents less than 40 % follow different pattern with comparison to those larger than 40 %. When the replacement of fly ash is larger than 40%, there is an abnormal extremum point before the minimum value on the electrical resistivity curve; with the addition of fly ash, the electrical resistivity curve is higher at early stage but lower at late stage, and the minimum point of the curve is retarded, and the corresponding electrical resistivity value of the minimum point is higher, with comparison to the pastes with lower content of FA and the plain paste.