Two kinds of Type I portland cements were selected for the study and were designated as T-1H and T-1D, respectively. The chemical compositions of the two cements, the Class F fly ash, and the slag are given in Table 1 in terms of oxide mass percents. The LOI of the fly ash is low compared to most class F fly ashes, since this fly ash was chosen for its low carbon content and hence negligible effect on air entrainment.
| Table 1. Chemical compositions of cements, fly ash and slag used (mass %) | ||||
|---|---|---|---|---|
| T-1H | T-1D | Fly ash | Slag | |
| SiO2 | 20.1 | 21.15 | 61.3 | 34.66 |
| Al2O3 | 5.6 | 4.41 | 19.4 | 11.37 |
| Fe2O3 | 2.5 | 3.69 | 4.5 | 0.86 |
| CaO | 64.7 | 62.95 | 9.1 | 45.44 |
| MgO | 0.8 | 2.53 | 2.3 | 8.53 |
| SO3 | 3.4 | 2.57 | 0.2 | 3.03 |
| K2 | 0.76 | 0.58 | 1.06 | 0.41 |
| Na2O | 0.14 | 0.18 | 0.3 | 0.22 |
| LOI | 1.2 | 1.32 | 0.1 | 0.91 |