Investigation of Durability Performance of High Plasticity Silty Soil Improved with Alkali Activated Fly Ash and Polypropylene Fiber

This study investigates the effects of parameters such as activator content, the type of fiber reinforcement, and fiber content on the durability characteristics. While conventional methods often focus on wetting-drying or freezing-thawing cycles for durability evaluation, the study emphasizes the importance of soaking tests, simulating field conditions more accurately. In soil improvement applications, the brittleness of the material increases with the use of both conventional and alkali-activated binders. Fiber reinforcement is a common practice to address this issue and enhance ductility. The study reviews various types of fibers and their roles in improving different aspects of soil properties. Notably, the use of hybrid fibers, combining different types and lengths, is explored for its potential to improve the durability of soil layers. The experimental part of the study investigates the behavior of high plasticity silty soil stabilized with fiber reinforcement and alkali-activated fly ash against soaking effects. The study considers the effects of the Na2SiO3/NaOH ratio, 3 mm and 12 mm length fiber content, and combinations of these fiber lengths on deterioration, the unconfined compressive strength (UCS), strength reduction of soaked samples. The durability performance of the samples is evaluated through various soaking periods. Results indicate that the use of hybrid fibers, combining different lengths, shows promise in improving the durability properties of stabilized soil layers.