钢屑导电水泥砖的电热性能研究

Electrothermal Properties of Conductive Cement Bricks Prepared from Steel Chips

为循环利用工业固体废弃物,实现传统建材的功能化,利用复掺钢渣和钢屑制备了导电水泥砖。结果表明:随着钢屑掺量的增加,样品的电阻率呈现先大幅度下降后逐渐平缓的趋势,钢屑的最佳掺量为5%;早龄期水泥砖导电主要依靠内部水分,28d后样品的干燥基本完成,电阻率也趋于稳定,稳定后水泥砖的导电效果是钢屑和钢渣共同改性的结果;室温条件下,水泥砖样品在30V直流电压下,通电120min内,同一测试点的温升?T达到了33.9℃,平均升温速度达到了0.28℃/min,具有优秀的发热效果;升温过程中,样品的电阻随着温度的升高呈现先下降后上升的变化规律,针对这一规律进行数据拟合,给出相关拟合参数,并进行了理论分析,发现这种电阻的变化规律与电极网的接触电阻变化和钢屑的热膨胀效应有关。

In order to recycle industrial solid waste and achieve the functionalization of traditional building materials,conductive cement bricks were prepared by mixing steel slag and steel chips.With the addition of steel chips,the resistivity of the sample decreases significantly,and the optimal amount of steel chips is 5%.The conductivity of early age cement bricks mainly relies on internal moisture.After 28 days,the drying of the sample is basically completed,and the resistivity also tends to stabilize.After stabilization,the conductivity of cement bricks is the result of modification with steel chips and slag.Under room temperature conditions,the cement brick sample was electrified at 30V DC voltage for 120 minutes,and the temperature riseΔT at the same test point reached 33.9℃,with an average heating rate of 0.28℃/min,which has excellent heating effect.During the heating process,the resistance of the sample shows a pattern of first decreasing and then increasing as the temperature increases.Data fitting was conducted on this rule,relevant fitting parameters were provided,and theoretical analysis was conducted.The variation pattern of this resistance is related to the contact resistance change of the electrode network and the thermal expansion effect of steel chips.