METHOD OF DETERMINING WATER IMPERMEABILITY OF CONCRETE OF HYDRO-ENGINEERING STRUCTURES DURING OPERATION (VERSIONS)

摘要

FIELD: construction.;SUBSTANCE: invention can be used for determining water impermeability of concrete of hydro-engineering structures during operation. The essence of the invention lies in that cylindrical model samples are made from the same concrete as the nominal structure, using the same technology and hardening mode as the control structure. Water impermeability of model samples is determined through action of a water head with incrementally increasing pressure on one of the surfaces of the sample, sealed on its perimeter until onset of filtration signs in form of separate water drops. The filtrate is collected and its volume is measured. The filtration coefficient of the concrete of the model samples is calculated. Ultrasonic oscillations are stimulated in the model samples before and after carrying out filtration tests and in the construction material before filling it with water and after its evacuation. The time and speed of transmission of the ultrasonic oscillations in the model samples and in the concrete of the real structure is measured. The change in the speed of ultrasonic oscillations is calculated on the difference in speed of transmission of ultrasonic oscillations in the model samples before and after carrying out filtration tests and in the material of the structure before filling it with water and after its evacuation. Calibrated graphs of change in speed of ultrasonic oscillation against filtration coefficient are drawn for concrete of different composition, production technology and hardening mode. On the corresponding working calibrated graphs and the established change in the speed of ultrasonic oscillations of the material under natural conditions, water impermeability of the concrete in the real structure is determined.;EFFECT: lower labour input and duration of the investigative work on determining water impermeability of concrete in real hydro-engineering structures.;2 cl