Effects of fine aggregate on the properties of calcium phosphate cements

The effects of the presence of carbonate and calcium phosphate aggregate on the mechanical properties of calcium phosphate cements were explored. Calcium phosphate precursors reacted to form hydroxyapatite at the binder phase. The effects on mechanical properties correlated with the quality of the interfacial bond developed. CaCO₃ and 3CaO.P₂O₅ aggregates are not inert when constituted with calcium phosphate cement and are consumed with time. Mechanical properties and paste microstructure also showed a dependence on the composition of the mixing solution. NaHCO₃ dissolved in the mixing solution reacts to form a carbonated hydroxyapatite and this resulted in changes in both compressive strength and morphology.