Investigation of MgO and CaO/Al₂O₃ polyphosphate cements

Calcined magnesia and two high-alumina cements, i. e. Secar 51 and Secar 71, were combined with solutions of Na polyphosphate with chain lengths between n = 4 and n = 30. The resulting pastes exhibited setting time and strength development that depended on the poly phosphate chain length and curing conditions. A distinct chemical shrinkage accompanied the hardening process.