عنوان مقاله [English]
Concrete mix-design specifications for concrete lining of irrigation canals in different regions are often considered the same by designers. However, the destructive factors of durability and instability of this structure are not same in different environmental conditions and so separate designs must be presented in different conditions. In this study 9 types of concrete mixes including: 3 grades of cement level, 3 ratios of (W/C) ratios and 3values of AEA were prepared. To determine specifications of durable concrete for irrigation canals in cold regions, various laboratory experiments on fresh and hardened concrete was performed. Cement grades of 325, 350 and 375 kg/m3 of concrete and w/c ratios of 0.4, 0.45 and 0.5, as well as AEA values of 0% (without AEA), 0.01 and 0.03% of cement weight was used. After preparing the concrete mixtures, different experiments on fresh concrete, including determination of slump, total air percentage, density and hardened concrete, including water absorption tests, compressive strength, modulus of elasticity and freezing-thawing cycles were performed up to 300 cycles. Based on the results, among the 9 concrete mixes samples, 3 mixes were durable in frost condition and were compatible with cold regions. These mixtures are as follows: 1- A mixture with a W/C ratio of 0.4, a cement grade of 350 kg/m3 and without AEA, 2- with a W/C ratio of 0.45 and a grade of 350 kg/m3 with 0.03% by weight of cement AEA, and 3- the W/C is 0.45 and the grade of cement is 325 kg/m3 without AEA. It was also found that using 1 to 2 kg/m3 of Concrete super plasticizer, the W/C ratio can be reduced to 0.4 and the concrete lining can be durable without using of AEA.