University of Tehran Civil Engineering Infrastructures Journal 2322-2093 Articles in Press 2026 01 21 Effect of Pectin Activated by LABSA on Clay Soil Properties 105605 10.22059/ceij.2026.390537.2252 EN Mohammed Fattah University of Technology - Iraq Zubaida Saad Ali University of Technology - Iraq Ahmed S.A. Al-Gharbawi Baghdad - Al-sinaa Street Journal Article 2025 02 14 This paper studies the stabilization effect of pectin biopolymer and linear alkyl benzene sulfonic acid (LABSA) on clayey soil. Stabilization of soil by biopolymers has been the focus of several studies, but the use of pectin as a soil stabilizer was scarcely used, let alone the combination of pectin with LABSA. Pectin is a polysaccharide biopolymer naturally found in plants cell walls. It can bind clay particles, together and increase cohesion between particles. This binding comes from gel formation behavior that is further activated by acid for the unconfined compressive strength USC test. Hence, the LABSA, which was diluted in distilled water at three concentrations (100/1000, 200/1000, and 300/1000) ml has been added to the soil in the form of liquid-solid with two concentrations (1% and 2%) by weight of dry soil for the unconfined compression test. While Pectin alone in three presents (0.5, 1, 2) % by Wt. for other tests. The results showed that the specific gravity, maximum dry density, and optimum moisture content decrease, and Atterberg limits increase with the increase in pectin concentration. UCS increased to 306 kPa at (300/1000 ml, 20-80% solid-liquid). https://ceij.ut.ac.ir/article_105605_5eda472d93c56cc2edbbedeaef17d445.pdf