Crack resistance and frost resistance are important factors affecting the performance of road cement concrete. In order to compare the effects of mineral admixtures such as fly ash, silica fume and slag powder on the plastic cracking and frost resistance of cement concrete, the plastic cracking time, number and area of cracks, Cl－ diffusion coefficient and relative dynamic modulus of cement concrete was determined by the flat plate method, electric flux method and slow freezing method. The results show that: mineral admixture can accelerate or delay the occurrence time of plastic cracks in concrete. The amount of doping was positively correlated with the average cracking area and the cracking area per unit area, but there was no significant correlation with the number of cracks. Mineral admixtures can effectively reduce the Cl－ diffusion coefficient of concrete. However, after the dosage exceeds 20%, the rate of decrease is slowed down. The effect of mineral admixtures on improving the frost resistance durability of concrete has become more apparent in the late stage of freezing and thawing. When the dosage is appropriate, the three admixtures can achieve similar effects. After the excess, the relative dynamic elastic modulus showed a downward trend, and the decline in the late freeze-thaw period was more significant.

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