The three activators featured very discriminated behaviors. Sodium hydroxide induced a very fast hardening with almost 15 MPa after 24 h of curing, but the strength increase subsequently slowed down to reach only 32 MPa at 28 days (672 h). Sodium carbonate had a completely different influence, with almost no measurable strength during about 9 days (about 200 h). The strength suddenly rose to overtake the sodium hydroxide-activated sample at 14 days (about 350 h) and ended at around 42 MPa at 28 days. Sodium silicate appeared to produce a slower hardening than hydroxide in the first two days. However, the strength became higher than the other two systems afterwards, to eventually reach the highest performance with 65 MPa at 28 days.