Special anti-freezing agent for high-performance concrete in severe cold area and cold-resistant high-performance concrete

The invention discloses a special anti-freezing agent for high-performance concrete in severe cold areas and cold-resistant high-performance concrete. The anti-freezing agent comprises the following raw materials in parts by mass: 6-10 parts of sodium thiocyanate, 5-8 parts of calcium nitrate, 7-10 parts of a composite phase change material, 3-5 parts of carbide slag nano powder and 3 parts of sodium citrate. The high-performance concrete is prepared from the following raw materials in parts by mass: 330 to 360 parts of ordinary Portland cement, 60 to 90 parts of fly ash, 630 to 660 parts of fine aggregate, 1150 to 1200 parts of coarse aggregate and 8 to 10 parts of high-performance polycarboxylate superplasticizer. The high-performance concrete also comprises 7.5-9 parts of the special anti-freezing agent for the high-performance concrete used in the severe cold area. The anti-freezing agent provided by the invention is specially applied to severe cold regions (the temperature fluctuation reaches-15 DEG C to