Experimental Investigation of Joint Filling Materials Performance on Preventing Seepage in Lined Open Concrete Canal (Laboratory and Field Model)

摘要

Seepage is one of the most serious problems of water loss in the irrigation canals. In Iraq, most projects of concrete lining irrigation canals suffer from seepage losses phenomena through joints. The loss of water due to seepage from irrigation canals constitutes a substantial part of the usable water. The aim of this study is to reduce or prevent the seepage by using new alternative joints filling materials. The methodology in this study follows two main categories for calculating and studying the seepage and efficiency of some alternative materials, hoping to apply a new filling joint material, and assessing their performance to prevent seepage. The first category was done by constructing a trapezoidal concrete canal model. The joints filling materials used in this research were : cement-sand mortar, cement-sand mortar with Styrene Butadiene Rubber (SBR), cement-sand with Krystol Internal Membrane (KIM), and Setseal B (liquid polymer with powder). The average percentage of seepage losses was reduced to about 11.3, 29, and 89% when using cement-sand mortar and SBR, cement-sand mortar and KIM, and Setseal B respectively, as joints filling material instead of cement-sand mortar (the initial filling material). While when using Setseal B as a coating material for 9 months duration give no seepage (zero seepage). The second category was carried out by field study, which was done on a branch of irrigation concrete Setseal B as a coating layer was applied on the existing cement-sand joints of the canal (based on the results of the laboratory model tests). It has been tested for 3 weeks. The average reduction percentage in water losses was about 62.5%, by comparing it with using cement-sand mortar only as joints filling material.