Abstract:
A dredged sediment obtained from a process of excavating or removing sediments from river is classified as waste materials with high water contents. A reuse of the dredged sediments as pavement materials to solve environmental problems is interesting. However, the dredged sediment without treatment is unable to be directly used as road materials due to low shear strength and low bearing capacity. This research presents an improvement of dredged sediments by adding admixtures including cement and fly ash to enhance the strength. The large amount of fly ash was used to decrease for cost effectiveness purpose. Experiments consisted of unconfined compressive strength, wetting-drying durability, splitting tensile strength test, resilient modulus test, ultrasonic pulse velocity tests and free-free resonance test. For microstructure analysis consisted of SEM (Scanning electron microscope), EDX (Energy dispersive X-ray spectroscope), XRD (X-ray diffraction) and TGA (Thermogravimetric analysis). Results show that 10% fly ash content provided maximum strength, durability, resilient modulus and wave velocity. The classification of treated sediments in this study was based on standard of Department of Highways.