CEMENT AND CONCRETE RESEARCH, vol.21, no.5, pp.765-776, 1991 (SCI-Expanded)
Synthetic tricalcium aluminate and gypsum mixtures containing 0, 0.10 and 0.25 wt. % sulphonated melamine formaldehyde (SMF) have been prepared to a constant water:solid ratio of 2.0 and hydrated at 20-degrees-C. The hydration processes have been studied by calorimetry, differential thermal analysis, X-ray diffraction and electron microscopy. By 72 hr all mixtures had reached essentially the same phase distribution but the SMF content strongly influenced reaction pathways. Absorption of SMF is largely responsible; it bulks out and helps stabilize ettringite precursor. The SMF content and reaction sequence markedly affect the microstructure of the set pastes.