水泥净浆梁通电时的变形效应

DEFORMATION EFFECT OF HARDENED CEMENT PASTE BEAM INDUCED BY ELECTRICAL FIELD

研究了水泥净浆梁在通电时的变形效应,即电力效应。研究表明:在水泥净浆梁厚度方向通电时梁上下表面出现温度差。接电源正极的表面温度总高于接电源负极的表面。由于温度差的存在,梁朝向温度高的一面(即接电源正极的一面)变形;电力效应是电致温度差和水泥孔隙中电解质溶液产生电渗的共同结果。在水泥净浆中加入氯化钠电力效应会更明显。

The deformation effect of hardened cement paste beam induced by an applied electrical field was investigated. This effect is also called the electromechanical effect. Results show that there is a temperature difference between the upper surface and the lower surface of the beam in the thickness direction when an electrical current is applied to these surfaces. The tempera- ture of a surface connected with the anode of the electrical charge is always higher than that of a surface connected with the cathode. Due to the temperature difference, the beam bends towards the surface with a higher temperature. Deformation induced by this electrical field in cement is the result of temperature difference and the electroosmosis behavior of electrolyte solvent in the porous cement matrix. The electromechanical effect becomes more obvious as adding NaCI to cement paste.