# A Review on the Performance of Concrete Containing Non-Potable Water
## 2 Methodology  
As mentioned above, the main objective of this study is to find the effect of WW (treated and untreated) on the performance of concrete. Thus, an extensive literature review was performed to collect the studies that use WW as \"mixing water\" in concrete [6; 9; 10; 11; 12; 13; 14; 15; 16; 17; 18; 19; 20; 21; 22; 23; 24; 25; 26; 27; 28; 29; 30; 31; 32; 33; 34; 35; 36; 37; 38; 39]. As shown in Table 1, different types of WW have been used in concrete and their effects on the fresh, mechanical, and durability properties of concrete were considered. Regarding the content of non-conventional water used in concrete, 2/3 of the studies investigated concrete made with NPW as 100% replacement of potable water while others studied concrete with different replacement levels of the potable water with NPW (mostly 25%, 50%, 75% and 100%).  
In order to identify the effect of each selected NPW, their chemical and physical properties were studied in Section 3. This section was needed to understand their effects on the performance of concrete in terms of physical and chemical changes. After that, fresh properties such as slump (Section 4.1), setting time (Section 4.2) and air content (Section 4.3) and hardened properties such as compressive strength (Section 5.1), tensile strength (Section 5.2), hardened density (Section 5.3), water absorption (Section 5.4) and chloride ion penetration (Section 5.5) have been studied.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Study No.** & **Authors** & **Types of Water** & **Incorporation** & **Fresh** & **Mechanical** & **Durability** \\  & & **Ratio (\%)** & **Properties** & **Properties** & **and Others** \\ \hline
1 & [PERSON] and [PERSON] (1986) & Treated WW & 0, 25, 50, 75 & – & CS & WA \\  & & Untreated WW & 0 and 100 & – & CS, ST & H\({}_{2}\)SO-AACIP \\  & & Fertilizer factory WW & 1 and 100 & – & CS & WA, H\({}_{2}\)SO-AA \\
2 & [PERSON] et al. (2021) & Textile factory WW & 2 and 100 & – & CS & WA, H\({}_{2}\)SO\({}_{4}\)-AA \\  & & Sugar factory WW & 3 and 100 & – & CS & WA, H\({}_{2}\)SO\({}_{4}\)-AA \\  & & Service station WW & 4 and 100 & – & CS & WA, H\({}_{2}\)SO\({}_{4}\)-AA \\
3 & [PERSON] et al. (2021) & Treated WW & 0 and 100 & – & CS, ST & ER, CIP, D\({}_{\text{mmsh}}\) \\
4 & Al-ghussain and Terror (2003) & Preliminary treated WW & 0 and 100 & ST & CS & HD \\  & & Secondary treated WW & 1 and 100 & ST & CS & HD \\  & & Tertiary treated WW & 2 and 100 & ST & CS & HD \\
5 & [PERSON] (2010) & Treated WW & 0, 25, 50, 75, 100 & – & CS & CIP \\  & [PERSON] and & Wet recycling process & & & & \\  & [PERSON] (2012) & WW & 0, 25, 50, 75, 100 & – & CS, ST, FS & WA, CIP, WAC \\  & Sultan and Islam & Untreated WW & 100 & ST, SL & CS & UPV \\
7 & (2018) & Treated WW & 100 & ST, SL & CS & – \\
8 & [PERSON] et al. (2015) & Untreated WW & 75, 100 & ST & CS & – \\
9 & [PERSON] (1989) & Treated WW & – & ST, SL & CS & WA, HD \\  & [PERSON] and & & 0, 20, 40, 60, 80, & ST & CS, ST & – \\  & [PERSON] (1991) & Treated WW & 100 & – & ST, SL & – \\
11 & [PERSON] & Untreated WW & – & ST, SL & – & – \\  & & & & & & \\ \hline \hline \end{tabular}
\end{table}
Table 1: Tests and type of WW used in concrete based on the selected studies.