# Feasibility of Non-Remanufactured Waste Bottle Glass as Supplementary Cementitious Material
## 2 Methodology
### Mortar Study
#### 2.2.3 The mechanical Strength  
Three prismatic specimens (40 \(\times\) 40 \(\times\) 160 mm\({}^{3}\)) were produced for each mortar type (see Table 4) and age, namely, 7, 28, 56, and 84 days, and tested according to EN 196-1. Specimens were kept under water curing (20 \({}^{\circ}\)C) until the testing date. The electrical resistivity for mortars (presented in Table 4) between 7 and 84 days was measured on 40 \(\times\) 40 \(\times\) 160 mm\({}^{3}\) specimens for each mortar type presented in Table 4. The specimens were kept under water at a controlled temperature (20 \(\pm\) 2 \({}^{\circ}\)C) and removed to perform the resistivity test at established ages. At two opposite surfaces of the specimen, stainless steel grids were embedded (during casting) and used as electrodes (see Figure 5). For the two-electrode resistivity method assessment, alternating current was preferred. As such, a signal generator performed a sinusoidal wave with a peak voltage of \(\pm\)10 V and a frequency of 100 Hz. Then, a digital multimeter (Keithley) measured the resulting current. The electric resistivity (\(\rho\)), \(\Omega\) m, was calculated by multiplying the resistance by the cell constant, which for prismatic specimens is the ratio of the surface area to the length. The following equation applies:  
\[\rho=\frac{VA}{IL} \tag{1}\] \begin{table}
\begin{tabular}{p{56.9 pt} p{56.9 pt} p{56.9 pt} p{56.9 pt} p{56.9 pt}} \hline \hline \multicolumn{1}{c}{**Test Standard**} & \multicolumn{1}{c}{**Curing Regime**} & \multicolumn{1}{c}{**Testing Age**} & \multicolumn{1}{c}{**Number of Samples for Each Age and Each Mortar Type**} & \multicolumn{1}{c}{**Sample Geometry and Size**} \\ \hline Mechanical strength & NP EN 196-1 & & 7, 28, 56, and 84 days & 3 & Prismatic 40 \(\times\) 40 \(\times\) 160 mm\({}^{3}\) \\ \hline Electrical resistivity & Two-electrode method & & 7, 28, 56, and 84 days & 3 & Prismatic 40 \(\times\) 40 \(\times\) 160 mm\({}^{3}\) \\ \hline Water absorption by capillarity & RILEM TC 116-PCD & & 42 days (28 days wet curing + 14 days at 40 \({}^{\circ}\)C, until constant mass achieved) & 3 & Prismatic 40 \(\times\) 40 \(\times\) 45 mm\({}^{3}\) \\ \hline Resistance to chloride migration & NT Build 492 & Water curing at 20 \({}^{\circ}\)C & 20 \({}^{\circ}\)C & & Cylindrical h = 50 mm, \(\Omega\) = 100 mm \\ \hline \multicolumn{1}{c}{Resistance chloride migration} & NT Build 492 & & 28 days & 3 & Prismatic 40 \(\times\) 40 \(\times\) 160 mm\({}^{3}\) \\ \hline Carbonation resistance & RILEM CPC-18 & & & \\ \hline \multicolumn{1}{c}{} & \multicolumn{1}{c}{} & \multicolumn{1}{c}{} & \multicolumn{1}{c}{} & \\ \multicolumn{1}{c}{} & \multicolumn{1}{c}{} & \multicolumn{1}{c}{} & \multicolumn{1}{c}{} & \\ \multicolumn{1}{c}{} & \multicolumn{1}{c}{} & \multicolumn{1}{c}{} & \multicolumn{1}{c}{} & \\ \multicolumn{1}{c}{} & \multicolumn{1}{c}{} & \multicolumn{1}{c}{} & \multicolumn{1}{c}{} & \\ \hline \multicolumn{1}{c}{} & \multicolumn{1}{c}{} & \multicolumn{1}{c}{} & \multicolumn{1}{c}{} & \\ Risk of alkali-silica reaction & ASTM C 1567 & & curing at 80 \({}^{\circ}\)C (according to ASTM C 1567) & Up to 28 days & 3 & Prismatic 25 \(\times\) 25 \(\times\) 250 mm\({}^{3}\) \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Experimental testing plan summary. where \(V\), voltage (volts); \(I\), current (A); \(L\), length (m); and \(A\) (m\({}^{2}\)) is the cross area of the test specimen through which current passes. The resistivity results were considered the average value from three specimens tested at each age. The RILEM recommendation TC 116-PCD was adopted to measure the water absorption by capillarity on three replicate prismatic specimens for each mortar type (Table 4). Firstly, the specimens were dried at 40 \({}^{\circ}\)C until constant mass. For the test, dried specimens were placed in a water bath with automatically adjusted water level at a constant depth of approximately 3 mm (see Figure 6).