## 3 Results  
_HYDCEM Predictions_  
Figure 4 show the developing solid phase chemistry of the 100% CEM II/A-LL pastes hydrating over 1000 days at 20 \({}^{\circ}\)C. Similar predictions of the solid phase evolution of the three blended cements are shown below, and not only are they remarkably similar in phase quantities but the rate at which the phases dissolve and precipitate are also comparable. Mix 2, or the '_control_' sample (50% slag + 50% cement, Figure 5), has been used as a reference blend on numerous studies by Ecocem in the past. In this case, the cement component is the CEM II/A-LL formulation used in this study.  
Comparing the final (1000 day) phase quantities with each other shows the total hydrate abundance for the two experimental glass-slag pastes (60% CEM II/A-LL + 40% GGBS/RCGP (Mix 3, Figure 6) and 40% CEM II/A-LL + 60% GGBS/RCGP (Mix 4, Figure 7) to be slightly greater and slightly less than that of the control paste (respectively), as shown in Figures 7 and 8. Regarding the solution compositions predicted by HYDCEM at 1000 days, again little difference is seen between the control (Mix 2) and the simulated slag-glass blends with CEM II/A-LL. In each case, the solution chemistry is dominated by sodium and potassium, calcium, silicate, carbonate and sulphate as the next most abundant dissolved ions. For each ion in solution, the variation in predicted concentration between each blended cement is not significant.  
Replotting this data into stacked columns (Figure 8) and normalised to 100 mol% (Figure 9) makes comparison of the results much easier and shows there is little difference between the blended cements. This shows that hydrate compositions in mixes 3 and 4 span that of the control sample (1:1 clinker:slag, without glass) and suggests that GGBS and RCGP will be consumed and react with portlandite from the clinker to form C(A)SH gel.  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \multicolumn{2}{c}{**Composition of Blending Components (Mass\%)**} & \multicolumn{3}{c}{**Composition of Paste Formulations**} \\ \hline Oxide & RCGP & GGBS & \multicolumn{2}{c}{CEM II} & \multicolumn{1}{c}{Control} & 40\% Blend & 60\% Blend \\ SiO\({}_{2}\) & 68.89 & 35.59 & 17.98 & 26.79 & 27.02 & 29.28 \\ CaO & 14.99 & 43.24 & 62.45 & 52.86 & 53.07 & 50.73 \\ MgO & 1.62 & 7.73 & 2.57 & 5.15 & 4.267 & 4.69 \\ Al\({}_{2}\)O\({}_{3}\) & 1.25 & 9.61 & 4.14 & 6.88 & 5.83 & 6.25 \\ Fe\({}_{2}\)O\({}_{3}\) & 0.34 & 0.77 & 2.85 & 1.81 & 1.99 & 1.78 \\ TiO\({}_{2}\) & 0.08 & 0.66 & 0.33 & 0.50 & 0.43 & 0.45 \\ Mn\({}_{3}\)O\({}_{4}\) & 0.04 & 0.15 & 0.24 & 0.20 & 0.20 & 0.19 \\ Na\({}_{2}\)O & 6.18 & 0.2 & 0.24 & 0.22 & 0.58 & 0.67 \\ K\({}_{2}\)O & 0.5 & 0.44 & 0.53 & 0.49 & 0.50 & 0.49 \\ CaCO\({}_{3}\) & 0 & 0 & 10.48 & 5.24 & 6.29 & 5.24 \\ Total & 93.89 & 98.39 & 101.81 & 100.14 & 100.18 & 99.77 \\ \hline \end{tabular}
\end{table}
Table 2: Relative oxide composition of the materials and of the formulations simulated (shaded).  
\begin{table}
\begin{tabular}{c c c c} \hline \multicolumn{2}{c}{**Proportion of Each Powder (\%)**} \\ \cline{2-4} \multicolumn{1}{c}{} & **CEM II/A-LL** & **GGBS** & **RCGP** \\ \hline
**1** & 100 & & \\
**2 (control)** & 50 & 50 & \\
**3** & 60 & 34 & 6 \\
**4** & 40 & 51 & 9 \\ \hline \end{tabular}
\end{table}
Table 3: Mix details.  
Figure 4: Solid phase evolution, pore solution chemistry and pH of Mix 1 (CEM II/A-LL) with a 0.5 w/b ratio, hydrating over 1000 days at 20 \({}^{\circ}\)C.  
Figure 5: Solid phase evolution, pore solution chemistry and pH of Mix 2 (50% CEM II/A-LL, 50% CGBS) with a 0.5 w/b ratio, hydrating over 1000 days at 20 \({}^{\circ}\)C.  
Figure 6: Solid phase evolution, pore solution chemistry and pH of Mix 3 (40% CEM II/A-LL, 60% blend) with a 0.5 w/b ratio, hydrating over 1000 days at 20 \({}^{\circ}\)C.  
Figure 7: Solid phase evolution, pore solution chemistry and pH of Mix 4 (60% CEM II/A-LL, 40% blend) with a 0.5 w/b ratio, hydrating over 1000 days at 20 \({}^{\circ}\)C.