White Cement-Based Binder for Self-Cleaning Fine-Grained Concrete

Introduction. The production of concrete products with complex shapes that are thin-walled, durable, and resistant to environmental influences — while retaining their decorative appearance during service and maximizing the use of industrial (secondary) mineral raw materials — poses a significant challenge. This challenge is particularly pronounced when producing white-colored products, as the range of suitable raw materials becomes severely limited. Additionally, reducing the Portland cement content in such concretes is essential. Therefore, a pressing task is the development of modern binders and concretes with reduced Portland cement content based on white-colored mineral components. Materials and methods. White Portland cement without mineral additives (PCB 1-500-D0 Cemix ProWhite, Cemix LLC, Republic of Bashkortostan) was used as the binder; expanded perlite sand (pozzolanic additive), microcalcite (carbonate additive), and anatase (photocatalytic additive), as well as their mixtures, were considered as additives; and polycarboxylate-based plasticizer Melflux 1641 F was employed to improve workability. The main physical and mechanical properties of the binder and the resulting cement stone — including normal consistency, mini-cone spread, and compressive strength — were evaluated according to standard procedures. Workability of the mixtures was assessed using rheological measurements, and the rate of heat release during cement stone hydration was determined calorimetrically. The study also examined the microstructural features of the resulting cement stone. Results. Replacing 40 % of cement with a complex of mineral additives in combination with a plasticizer mitigates the negative impact of fine components on the water demand of the mixture. This modification promotes intensified hydration, enhanced uniformity and density of the cement stone, and a reduction in the specific surface area and total nanopore volume of the cement stone by 39 % and 36 %, respectively. The presence of mineral additives enables the production of a binder achieving a compressive strength of 65.2 MPa after 28 days of standard curing.