Resistividad eléctrica superficial en el hormigón como ensayo no destructivo, comparando contenido de cloruros y resistencia a la compresión simple.

Abstract

This research investigates the surface electrical resistivity of concrete and compares it with the effect of chloride incorporation at different levels of compressive strength. To this end, six groups of ten 100 x 200 mm cylinders were prepared with different compressive strengths determined by their w/c ratios. The first four groups were prepared with w/c ratios of 0.60, 0.50, 0.40, and 0.35; for the remaining two groups, sodium chloride (NaCl) was incorporated at 1.5 % of the weight of the aggregates contained in their dosage, using w/c ratios of 0.50 and 0.40. Once the cylinders were cast and cured for 28 days, an additional 240 days were allowed to elapse before the electrical resistivity and compressive strength tests were performed. The results from the first four groups of cylinders yielded a very low correlation coefficient between electrical resistivity and compressive strength, whereas the two groups containing sodium chloride exhibited a relatively high correlation coefficient. The final values obtained in this investigation are unique, since the most recent publications on the relationship between electrical resistivity and compressive strength are based on tests conducted at 28 days, whereas this study presents results for concrete cylinders at an age of 268 days.