Heviuk I. Multimodal Portland-composite cements with high early strength and modified concretes on their basis

The dissertation is devoted to the development of theoretical bases of multimodal Portland cement technology with high early strength of CEM II/B-M type (clinker-factor 65%) due to optimization of the main constituents and granulometric composition of clinker and supplementary cementitious materials of different genesis taking into account the particle size distribution and their surface energy, which provides the technical, ecological and economic benefits of this type of Portland composite cement. An analytical review of literary sources devoted to the problems of obtaining of concrete with improved operational characteristics was made, issues related to the principles of modification of cementing systems were considered, as well as theoretical preconditions of the research were determined. The characteristics of the materials and the main methods of research used in the work are described. The results of development and research of multimodal composite Рortland cement with high early strength are presented. Complex estimation of dispersion of mineral components, based on determination of specific surface, granulometric composition of particles and magnitude of their interfacial surface is carried out. The complex of experimental and statistical models of technological and physical and technical parameters of quaternary multimodal composite Рortland cements with high early strength, quantitative characterizing the complex synergetic effect of highly dispersed cementitious substrates with bimodal reactive-chemical surface activity in the mechanism of growth of their early and standard strength are obtained. It is shown that the combination of the main constituents of different genesis provides optimization of properties (workability, standard and early strength, durability, cost, environmental impact) of a quaternary multimodal composite Рortland cement with high early strength of CEM II/B-M 42.5R type. The compositions of modified concretes based on multimodal Portland composite cements have been developed and their construction and technical properties have been investigated. It is shown that modified concretes of classes C20/25...С32/40 by the estimating specific strength fcm2/fcm28 =0,32...0,35 are characterized by average strength increase. The complex modifier with acceleration action Glenium ACE 430 + Pozzolit 501 provides the production of rapid-hardening concretes (fsm2=31,5 MPa, fcm2/fcm28 = 0,58), which are also characterized by accelerated hardening at frost. Industrial batches of Quaternary Portland composite cements of CEM II/B-M (S-P-L) type were produced. Pilot batch of multimodal Portland composite cement with high early strength DSTU B EN 197-1 - CEM II/B-M (S-P-L) 42.5R-LH has been produced on the basis of separate milling technology in the quantity of 600 t. At release of commercial concrete at the Subsidiary Enterprise "Spetszalizobeton" PJSC “Ivano-Frankivsk Cement”, the efficiency from the implementation of development, taking into account the cost of production, is 75 ... 100 UAH per 1 m3 of concrete.