Abstract
The paper considers the possibility of furfural hardening by oligomeric acid, which is both a hardener and a direct participant in the processes of polymerization and polycondensation. Low viscosity furfural-based binders, which gelling time is 40-60 minutes were developed. They can be used to produce highly filled materials having high physical and mechanical properties and chemical resistance to water and aggressive acidic media. The use of the developed binder as a protective compound for concrete structures is very promising. The coating partially contacts with the concrete surface forming insoluble phosphates.