Review article

The paper presents a comprehensive study of the strength and frost resistance characteristics of fine-grained concrete modified with air-entraining additives using a developed algorithm for the experimental method of computed tomography. The strength values of samples at the age of 28 days and after 200 freeze-thaw cycles were determined. The porosity in the cross-section of modified samples has been calculated using the computed tomography method. The relationship between porosity and strength has been established, and it is experimentally proven that increased porosity values have a positive effect on the durability of the structure under alternate freeze-thaw conditions, while under normal operating conditions, porosity has a negative effect on strength characteristics. The results obtained allow identifying the relationship between the structural characteristics represented by porosity and the strength characteristics of modified fine-grained concrete, as well as confirming the prospects for using computed tomography in studying the properties of building materials by a non- destructive method.