The difference in chloride ion diffusion coefficient of concrete made with drinking water and wastewater

In this study, the chloride ion penetration of concrete made with drinking water and domestic wastewater of the anaerobic pond (non-potable water) were evaluated through the experimental tests and finite difference method. We considered three mix designs with water to cement ratios between 0.4 and 0.6 for each category. We experimented the chloride ion percentage of the first eight layers of each concrete and then calculated their chloride diffusion coefficient by using the finite difference method (Implicit method). The results showed that the use of domestic wastewater increased the chloride ion percentage and chloride ion diffusion coefficient. Moreover, the homogeneous surfaces of concrete samples in using drinking water transformed into a new arrangement with more pores and voids, which can be a consequence of the presence of wastewater's impurities. Also, the high-resolution scanning electron microscopy (HRSEM) images and the field emission scanning electron microscopy (FESEM) images with energy dispersive X-ray (EDX) analysis of concrete surfaces before and after conducting the chloride ion test were provided to evaluate the morphological changes. Besides, a one-way analysis of variance (ANOVA) statistical test at the 5% significance level showed no significant difference between the chloride ion percentage of concrete in the experimental test and finite difference method. (C) 2019 Elsevier Ltd. All rights reserved.