Finally, the degree of reaction, , of C2S phases has been calculated using normalized data shown in Figure 2, according to the following expression [7]. Overall belite reactivities are also given in Table 3. These data quantitatively confirm the higher rate of hydration of 'H-C2S, and it can be graphically observed in Figure 2. It can be inferred from these data that cements with 'H-C2S will develop higher mechanical strengths from one month of hydration. A study aimed to produce larger amounts of clinkers to study both hydration reactions and strength developments is in progress.