# Use of Eoofriendly Glass Powder Concrete in Construction of Wind Farms
## 3 Results and Discussion
### Mechanical Properties of Concrete
#### 3.3.2 Simulation by Bolomey's Formula
\begin{table}
\begin{tabular}{c c c c c c c} \hline
**Bolomey Compressive Strengths (MPa)** & **Control** & **G15** & **G30** & **G45** & **G60** & **G80** \\ \hline _Cs_ 28 (Bolomey) apparent (_k_ = 0) & 34.5 & 23.7 & 14.9 & 8.1 & 0 & / \\ _Cs_ 28 (Bolomey) real (_k_ = 0) & 34.5 & 25.7 & 18.1 & 10.6 & 3.0 & / \\ Coefficient considering the apparent k addition at 28 days & / & 1.01 & 0.57 & 0.59 & 0.36 & 0.35 \\ Coefficient considering the real k addition at 28 days & / & 0.67 & 0.30 & 0.42 & 0.20 & 0.24 \\ Compressive strengths and coefficients considering the addition & & & & & & \\ _Cs_ 90 (Bolomey) apparent (_k_ = 0) & 39.6 & 27.2 & 17.1 & 9.3 & 0 & / \\ _Cs_ 90 (Bolomey) real (_k_ = 0) & 39.6 & 29.5 & 20.8 & 12.2 & 3.4 & / \\ Coefficient considering the apparent k addition at 90 days & / & 0.5 & 0.71 & 0.63 & 0.20 & 0.25 \\ Coefficient considering the real k addition at 90 days & / & 0.20 & 0.42 & 0.45 & 0.15 & 0.34 \\ \hline \end{tabular}
\end{table} 
Table 6: Results of Bolomey’s ‘apparent’ and ‘real’ compressive strengths. Figure 8: Compressive strength, \(Cs\), 90 days after setting, with regard to the amount of glass powder used to replace the cement (\(Gp\)). The results are compared to the Bolomey (real and apparent) corresponding ones. The determination coefficients of the linear fittings are \(R^{2}\) = 0.973 (\(C_{S}\) 90); \(R^{2}\) = 0.993 (\(C_{S}\) apparent Bolomey); \(R^{2}\) = 0.999 (\(C_{S}\) real Bolomey). Figure 7: Compressive strength, \(Cs\), 28 days after setting, with regard to the amount of glass powder used to replace the cement (\(Gp\)). The results are compared to the Bolomey (real and apparent) corresponding ones. The determination coefficients of the linear fittings are \(R^{2}\) = 0.988 (\(C_{S}\) 28); \(R^{2}\) = 0.999 (\(C_{S}\) apparent Bolomey); \(R^{2}\) = 0.993 (\(C_{S}\) real Bolomey). Figure 10: Evolution of the value of ‘\(k\) real’ depending on the amount of glass powder contained in the binder (_Gp_). Figure 9: Evolution of the value of ‘\(k\) apparent’ depending on the amount of glass powder contained in the binder (_Gp_). obtain the same compressive strength in a concrete produced with 60 kg of CEM I 52.5 R cement, it would be necessary to use 100 kg of glass powder. By obtaining the so-called Bolomey coefficients, the percentage of cement that can be replaced for glass powder in concrete to obtain a certain compressive strength can be calculated. According to Figures 9 and 10, for up to 50% replacement of CEM I 52.5 R cement by glass powder, the compressive strength values of concretes are sufficiently important to classify these concretes in the group of building concretes. It was observed that the decrease in compressive strength occurred linearly as a function of the percentage of glass powder in the binder. In this way, from the experimental results, taking into account the percentage of glass powder contained in the binder and the compressive strength obtained in the control specimen, Equation (7) has been deduced. Such an equation makes it possible to predict the compressive strength of the concrete, at a certain setting time, according to the amount of glass powder used to replace the CEM I 52.5 cement:  
\[Cs=-31V+Cs_{cem} \tag{7}\]  
where:  
\(V\) is the percentage of glass powder contained in the binder; and  
\(Cs_{cem}\) is the compressive strength of the concrete whose binder is only CEM I 52.5 R.  
Figure 11 shows the variation of compression strengths, for test ages of 2, 7, 28 and 90 days, of concrete manufactured with different replacement percentages of cement by glass powder. At above 50% replacement of CEM I 52.5 R cement by glass powder, the previous law is not applicable. The experimental values of compressive strength are lower than those obtained by this expression. From the values obtained for compressive strength, concretes studied can be classified in the group of concretes for paving roads and highways.