Low-porosity tricalcium aluminate hardened paste

The results of the study on the properties of the hardened tricalcium aluminate paste, prepared under the use of water/solid (w/s) ratio 0.08 and compaction pressure 300 MPa are presented. To the comparison to the reference paste (water/cement ratio 0.40, no pressure compaction) the pressed pastes shown more dense pore structure showing significant increase compressive strength. The increase represented ca 6000% under the hardening at 20 °C and ca 5000% at 90 °C. The effect of compressive strength decrease was probably a consequence of more intensive hydration of C3A at the higher curing temperature. The results also shown the C3A as a cement component having a positive response to the conditions of the combination of very low water:solid ratio and pressure compaction.