Abstract:
The paper investigates the application of statistical experimental design theory for a quantitative assessment of the influence of plasticizers of different chemical nature and dosage on the rheological, strength, and performance properties of concrete mixtures and hardened concrete. The relevance of the study is determined by the increasing requirements for construction materials used in critical structures, particularly civil protective and fortification facilities, where a balanced combination of high strength, sufficient workability, and increased density of concrete is essential.The feasibility of using second-order multifactor experimental designs with factor coding is substantiated, enabling the development of an exact analytical description of experimental results within the investigated factor space. Special attention is paid to the construction of polynomial models whose coefficients are determined in such a way that the calculated values exactly coincide with the experimental data at the nodal points of the experimental design. This approach eliminates the need for conventional statistical adequacy testing and allows focusing on the physical interpretation of the obtained dependencies.The experimental factors include the type of plasticizer, its dosage, the water-to-cement ratio, and the cement class. The response variables comprise workability of concrete mixtures, compressive strength at different curing ages, average density, and indirect indicators of water impermeability. Based on the developed models, optimal regions of the factor space are identified, ensuring enhanced workability of concrete mixtures without compromising design strength. The obtained results can be effectively applied to optimize concrete mix compositions in modern construction practice and in the design of protective structures.
