建筑固废材料的阻抗谱与力学性能和孔隙结构的关系

Relationship between Electrochemical Impedance Spectra of Varied Building Solid Wastes and TheirMechanical Property and Pore Structure

测试了不同建筑固废材料(加气砖、红砖、砂浆)的电化学阻抗谱,从Nyquist曲线中提取关键信息及参数,结合力学性能、压汞试验数据进行对比分析,揭示了阻抗谱参数与力学性能和微观结构的关系.结果表明:固废材料的抗压强度越高,电荷传递电阻(Rct2)越大,二者呈线性相关关系;固废材料中可溶性盐越多,孔溶液电阻(Rs)越小,砂浆的Rs值均在0.3Ω以下,而加气砖和红砖的Rs均大于55.0Ω.试件尺寸也会影响试件与电解质之间的接触电阻,主要体现在高频区圆弧直径的变化,试件尺寸越大,高频区圆弧直径越小.另外,建立了固废材料阻抗谱参数与抗压强度、孔隙率之间的内在关系,可以实现对固废材料性能的智能检测与快速评估.

By studying the electrochemical impedance spectrum variation law of different building solid wastes(aerated brick,red brick,mortar),the key information and parameters are extracted from the Nyquist curves,combined with the mechanical properties and mercury pressure test data,and the relationship between the impedance spectral parameters and mechanical properties and microstructure was revealed.The results show that the higher the compressive strength of the solid waste,the greater the charge transfer resistance(Rct2),and they have a linear relationship.In addition,the more soluble salts of the material,the smaller the pore solution resistance(Rs),the Rs value of the mortar is below 0.3Ω,and the Rs value of aerated bricks and red bricks are greater than 55.0Ω.The size of the specimen affects the contact resistance between the specimen and the electrolyte,mainly reflected in the change of the arc diameter in the high-frequency region,the larger the specimen,the smaller the arc diameter of the high-frequency region.The intrinsic relationship between the impedance spectrum parameters of the building solid wastes and the compressive strength and porosity established can realize the intelligent detection and rapid evaluation of the performance of the building solid wastes.