In addition to distilled and deionized water, the following reagents (analytical grade) were used for the silica extraction: hydrochloric acid (HCl), sodium hydroxide (NaOH) and ethyl alcohol (C3H6O). For production of the cement pastes, ordinary Portland cement (CP I) was used (NBR 5732/1991),17 similar to ASTM type I cement, deionized water and superplasticizer admixture polycarboxylate-based Basf Glenium® 51 (aqueous solution with 32.6% solids). The chemical composition and particle size distribution of the cement are shown in Table 1 and Figure 1, respectively.