Preparation of Sulphoaluminate-Alite Composite Mineralogical Phase Cement Clinker from High Alumina Fly Ash
Sulphoaluminate-alite cement (SAAC) was successfully prepared from high alumina fly ash. XRD analysis indicated that the optimal mineralogical phase of cement clinker was obtained under condition of MG=1.05, MS =0.95 at 1300oC, and C4A3 S reached the strongest intensity and is 58.73% in the phase of calcined clinckers. SEM observation showed that C4A3 S are well developed into regular diamond/hexagon-shaped crystal with the size of 1~3.5 μm in the clinker. Hydrated clinker exhibited its new formed dominant phases in AFt, C-S-H and Afm. Pillar shaped AFt and sheet shaped AFm coexisted among the colloidal C-S-H substrate. It is demonstrated that the prepared cement shows a compressive strength of 27 MPa (1d), 36 MPa (3d), 49 MPa (28d), and flexural strength of 5.9 MPa (1d), 5.9 MPa (3d), 6.1 MPa (28d), indicated that the hydration product owned a good mechanical strength at early ages and increased steadily in the later stages.
J.K. Kim, D.Z. Wo, L.M. Zhou, H.T. Huang, K.T. Lau and M. Wang
J. H. Li et al., "Preparation of Sulphoaluminate-Alite Composite Mineralogical Phase Cement Clinker from High Alumina Fly Ash", Key Engineering Materials, Vols. 334-335, pp. 421-424, 2007