RESULTS OF TECHNOLOGY TESTING FOR REPAIRING CANAL CONCRETE COATING

Purpose: to substantiate the efficiency of the technology for repairing concrete canal linings with bitumen-based polymer materials for reducing crack water permeability. Materials and methods. A laboratory facility to simulate the process of filtration through damaged concrete linings, including the pressure regime in the canals and the flow interaction with the soil base was used. Scaling relationships for linear dimensions, filtration rate, porosity coefficient and other parameters taking into account the similarity theory application, which allows simulating natural processes under laboratory conditions, were determined. Results and discussion. Based on the results of the field surveys of the canal section, lining damage was revealed: cracks up to 0.1 m wide, destroyed joints and peeling concrete, which led to water losses 9 times exceeding the norm of 7–10 l/(day m²). Such technical condition resulted not only in significant losses of water resources, but also in a decrease in the overall efficiency of the irrigation system. The use of the polymer material "liquid rubber" for the current repair of the concrete lining of the 10-X-4 canal has proven its high efficiency. After treating the damaged areas (cracks and expansion joints), filtration losses were reduced to acceptable values. Conclusions. The field studies of irrigation canals made it possible to identify various defects in the structures of concrete linings: cracks, destroyed expansion and temperature joints, and concrete corrosion. Based on the results of the calculations, it was determined that such defects lead to filtration losses of up to 40 %, with about 65 % of the canals requiring reconstruction. Laboratory tests confirmed significant filtration (even in the presence of concrete and concrete film linings), especially in areas of variable water levels on the canals. To restore the waterproofing properties of partially destroyed concrete coatings, a repair technology using the polymer material “liquid rubber” has been successfully tested. Pilot testing on the 10-X-4 canal section showed a reduction in filtration losses from 90 to 7–10 l/(day m²).