Important Practical Conditions for Getting the High-Quality Foam Concretes

Abstract

Introduction. The most important reasons justifying the relevance of the research on the practical methods of reducing the consumption of materials in construction industry have been distinguished. The priorities of the Russian Federation referring to the foam concrete technology have been outlined. The level of reliability of the Internet resources describing properties of the dispersedly reinforced foam concretes has been briefly evaluated. The aim of the study is to establish the relationships between the individual properties of fiber, its quantity to the mass of cement ratio, and the most important operational properties of foam concrete manufactured using a single-stage technology.Materials and methods. The types and properties of raw materials used in the experimental research, the methods for controlling the properties of mixes and hardened foam concretes have been defined.Results. The relationship between the speed of phase transition of the viscoplastic properties of the foam concrete mixes into the elastic ones and the possibility of getting a high-quality structure of the hardened foam concrete have been briefly theoretically justified. The physical reasons influencing the direction and speed of forming the raw material dispersed particle clusters in the structure of the interpore partitions of foam concrete mixes have been revealed, which are the important factors to be considered in practice to get the high-strength foam concretes. Depending on the fiber concentration in the concrete mixture composition, the specifics of the fiber physical nature influence on the speed of phase transition from viscoplastic to elastic state have been established. It has been proved that the synergetic effect of dispersed reinforcement is achieved when fiber concentration is enough to provide the significant acceleration of the phase transition. New experimental data on the influence of the individual properties of fiber on the rheological and physico-mechanical properties of D500 foam concrete has been obtained.Discussion and Conclusion. The scientific explanation of the reasons for emergence of the electret effect on the surface of synthetic fiber has been given. It has been revealed that the discovered effect is induced by the specifics of the foam concrete mixture preparation using a single-stage technology. The most important practical conditions due to be met to get the high-strength foam concrete have been determined.