Fine-grained concrete with composite binder for pile foundations in terms of environment and climate in China

Introduction . Fine-grained concrete has been widely used in construction industry of China and has remained the most "revolutionary" material in concrete construction technology over the past 10 years. Due to the rapid development of urban construction, land development, characterized by special environment and climate conditions for building high-rise and super high-rise buildings and structures, the development of highly efficient fine-grained highstrength concrete for foundations is required. Pile foundations are of particular importance in modern construction. Results . The article presents the results of obtaining fine-grained concretes of B25 and B30 classes with the developed composite binders for pile foundations having an increased water permeability W8 and frost resistance F300. Discussion and conclusion . The study of the microstructure showed a dense overgrowth of the pores of the cement stone, calcium and aluminum hydrosilicates were distributed in a uniform fringe on the contact zone with the aggregates, tightly fused into a single hydrogranate. It has been shown that for the compositions of fine-grained concretes with composite binders the cement consumption in the developed concretes is reduced by 12 per cent, while ensuring the required normative strength and increased water permeability and frost resistance. Taking into account the specific environment and climate conditions for soils in China, the developed composition will ensure high water resistance and durability of fine-grained concretes for pile foundations.