An experimental and theoretical approach to assessing the structure of fine-grained modified concretes

Introduction. The development of approaches to assessing structural characteristics of multicomponent modified concretes using non-destructive testing methods at all stages of hydration is a relevant means focused on ensuring optimal rheological and strength characteristics of concretes. Materials and methods. Modified fine-grained concrete was analyzed as the material under study, since its composition meets the requirements of additive technologies applied in the construction industry. Modification was implemented by introducing additives and mechanically activating the initial cement-sand composition. The strength of resulting specimens was controlled as of the onset of curing. Structure formation was studied using a computed tomography scanner. Results. A tomography data processing approach was developed to evaluate the modified concrete’s structure. Key aspects of the stage-by-stage processing of specimens’ images were identified and a solution was obtained for determining the threshold values of correspondence between image shades having different density structures. In the course of compa­ring the results of the strength and structure study, the value of the percentage ratio of inclusions was obtained for various densities during the curing process. Conclusions. The proposed data acquisition approach contributes to development of further research in this area; it can become a stage in developing a new concrete structure analysis method. The study of specimens at early curing stages in combination with non-destructive control methods contributes to (1) development of rapid assessment techniques, applied to the quality of materials, and (2) an efficiency increase in the process of development.