Potentiometric thick-film sensors for measuring the pH of concrete

Concrete carbonation is one of the main triggers of the corrosion process and hence of the premature deterioration of concrete reinforcements. In order to monitor and control the carbonation process, a potentiometric sensor using thick-film technology was developed. This paper includes the results of the research carried out to characterise the pH sensor, including the materials, response time, sensitivity, detection limit, reproducibility, reversibility and the study of chloride interference. The sensors have been studied in pore solutions and concrete specimens. The study shows that the thick-film sensor has a potentiometric response to variations in pH and is capable of providing continuous, real-time information on the progress of the carbonation front.