Behaviour of fly ash and eggshell powder as ternary blend in concrete /
Ashraf A. Alamen Teara
- xx, 302 pages : illustrations (some color) ; 30 cm. + 1 CD-ROM.
Faculty of Civil Engineering Technology
Thesis (Doctor of Philosophy) -- Universiti Malaysia Pahang Al Sultan Abdullah - 2026
Includes bibliographical references
Soft clay is a challenging soil due to its low strength and high compressibility, often causing significant engineering and economic problems. This study investigates the use of calcium-rich, cost-effective materials silica fume (SF) and cockle shell ash (CSA)to improve the engineering properties of kaolin clay. Laboratory tests conducted included specific gravity, Atterberg limits, compaction, particle size distribution, permeability, unconfined compression, unconsolidated undrained (UU) triaxial tests, energy dispersive X-ray spectroscopy (EDX), and scanning electron microscopy (SEM). Kaolin clay wasinitially stabilized with SF at 2%, 4%, and 6% to identify the optimum SF content basedon undrained shear strength (USS). CSA was then added at 3%, 6%, and 9% to theoptimal SF mix. Samples were cured for 1, 7, 14, and 30 days. Results indicate that addingCSA to SF-stabilized kaolin decreased specific gravity, plasticity index, and maximumdry density, while increasing optimum moisture content and USS. The optimal blend, 6%SF + 9% CSA (K6SF9CSA), achieved a 102.16% increase in USS after 30 days, withUU tests recording the highest cohesion (53 kPa) and friction angle (22.05°). Thesefindings demonstrate that SF and CSA combinations can serve as effective, sustainable,and economical stabilizers for soft kaolin clay, offering significant improvements instrength and mechanical performance.
THE0010817 (Local)
Faculty of Civil Engineering Technology--Dissertations