Highly dispersed powders containing alpha-tricalcium phosphate as the
main constituent, produced by a sol-gel process and subsequent heating
to at least 1300 degrees C, exhibit hydraulic properties if allowed t
o react with water. Both pastes and compacts made from such powders ex
hibit setting and hardening, especially in the presence of sodium phos
phate, potassium phosphate, and ammonium phosphate, which act as catal
ysts. The product of the hydration process is hydrorxy-apatite in comb
ination with a C-S-H and/or C-S-P-H gel.