聚合物涂层砂浆试样的交流阻抗谱研究

STUDY ON THE ALTERNATING CURRENT IMPEDANCE SPECTRA OF POLYMER COATED MORTAR SPECIMENS

研究两种不同类型的聚合物涂层 (丁苯乳液和氯化聚氯乙烯溶液 )对砂浆试样的交流阻抗谱的影响及其对氯离子的抗渗性效果 .试验发现 ,涂层砂浆试样的阻抗谱在高频区有一半圆 ,半圆的大小能够表征涂层的抗渗性 .涂层厚度对阻抗谱的影响随涂层种类不同而不同 .涂层试样在氯化物扩散前后的阻抗谱的研究表明 ,丁苯乳液涂层试验后更加密实 ,适合于混凝土的修补 ;但CPVC涂层扩散后电阻大大降低 。

Polymeric coatings are widely used materials for repairing of steel bar reinforced concrete.In this paper,the influence of coatings on the permeability was studied with the alternating current impedance spectroscopy.Two types of polymer coatings (styrene-butadiene rubber latex (SBR)and chlorinated polyvinyl chloride solution (CPVC))were used.The test results showed that the alternating current impedance spectra (ACIS)of the polymer coated mortar specimens had a semi-circle in the high frequency range,and the diameter of the semi-circle indicated the permeability of the coatings.It was also found that the thickness of coatings had different influence on the ACIS depending on the type of coating.The comparison of the ACIS of the coated mortar specimens before and after chloride migration test demonstrated that the SBR was suitable for repairing because the resistance of the coating increased after migration test.However,the CPVC was not suitable for repairing because the resistance of the coating was enormously reduced after migration test.