Effect of fly ash on the strength properties of cohesive soils for roadbed reinforcement

Tóm tắt

DOI: https://doi.org/10.66195/mtu.2025.14.114

The reinforcement of cohesive soils for roadbed construction is critical to ensure long-term stability and performance of transportation infrastructure. This study explores the effects of fly ash, a byproduct of coal combustion, on the strength properties of cohesive soils, aiming to improve their suitability for use in roadbed applications. Laboratory experiments were conducted by mixing fly ash in varying proportions (ranging from 10% to 50% by weight) with locally sourced cohesive soil. Key geotechnical tests, including unconfined compressive strength (UCS), Maximum Dry Density, Atterberg limits, and compaction characteristics, were performed to evaluate changes in strength and consistency. Results indicate that the addition of fly ash led to a significant increase in UCS, especially at 20–35% fly ash content, shows improved load-bearing capacity and structural integrity. Furthermore, the plasticity index was reduced, and optimal moisture content slightly increased, reflecting favorable modifications in soil behavior. These improvements are attributed to pozzolanic reactions between fly ash and soil particles, leading to the formation of cementitious compounds. compounds. The study concludes that fly ash is an effective and sustainable stabilizing agent for cohesive soils, offering both environmental and engineering benefits for roadbed reinforcement and wider civil engineering applications.