Experimental study of asphalt concrete as the optimal material for lining irrigation canals

Introduction. The main losses of water in irrigation systems occur due to filtration, determined by the properties of the soil in which the canal passes. Loss due to filtration in irrigation systems amounts up to 50% of the water taken for irrigation. In addition to the physical and chemical properties of the soil, the size of the wetted perimeter, the water horizon in the canal, the groundwater level and other factors are also of great importance. Methods and materials. The selection of asphalt concrete proportioning was carried out by laboratory method and Tsiat curves. The study was carried out on the chemical and physical properties of Shymkent bitumen and their mixtures with Aktau bitumen; loess aggregate, limestone and Shymkent cement were used. Micro- and nanostructural analysis of the resulting asphalt concrete was carried out by scanning electron microscope (SEM). Results and discussion. Asphalt concrete prepared with cement has shown a decrease in temporary compressive strength at 50°C by 70–38%, prepared with limestone – by 47–33%, and prepared with loess – by 66–20%. Conclusion. Ground limestone turned out to be the best aggregate for asphalt concrete, as it produces higher quality asphalt concrete than other aggregates. Ground limestone gives a particularly dramatic increase in the quality of asphalt concrete in fine-grained asphalt concrete. An increase in temperature from 20 to 50°C sharply reduces the temporary compressive strength of asphalt concrete and less sharply with an increase from 50 to 70°C.