The Influence of Mass Absorption and Technological Damage of Concrete on the Contact Strength During the Restoration of Buildings and Structures

The materials of experimental studies of mass transfer in the contact zone of old and new concrete with the determination of the mass absorption of old concrete, depending on the composition of new concrete, are presented. In order to restore the serviceability and ensure the solidity of prefabricated monolithic structures, mass absorption in the contact zone of old concrete with new concrete was studied depending on the composition of the new concrete and the time of their contact. The value of mass absorption in the contact zone is experimentally determined, which varies with time and depends on the composition of the concrete mixture cast on the sample. The water-cement ratio maximizes the adhesion of old and new concrete in the contact zone. The amount of fine aggregate also significantly affects the mass absorption value. It has been confirmed that the value of mass absorption can be used to predict the values of the normal and tangential strengths of old and new concrete in prefabricated monolithic structures.