Recently, two concrete-admixture-makers developed the new-type non-freezing agent. They are said to have following excellent qualities. 1) Lower alkalinity and no chloride. 2) Freezing temperature of concrete will be dropped and initial frost damage after placing concrete will be protected. 3) Hydration of cement will be promoted at lower temperature. Experimental Results. (1) Using concrete with non-freezing agent, water content per unit volume will be reduced to common AE concrete without agent. (2) Properties for time proceed of fresh concrete was done by the measuring values of slump, air content and temperature for 90 minutes at air temperature about-9.0°C those values were similar to the non-freezing agent. (3) The initial frost damage was not suffered from concrete with non-freezing agent and concrete strength increased favorably. At 91-day, as to 20°C curing concrete strength with no agent, low temperature curing concrete strength with agent reached to nearly values. (4) The period on purpose to pro-tect early age frost damage of concrete with 50 kgf/cm2 strength was reduced highly using an agent. (5) If we add new-type non-freezing agent for the concrete, period of cold weather concreting can be shortened greatly.
