EFFECT OF FLYASH AND EGGSHELL POWDER ON THE SHEAR STRENGTH OF CLAYEY SOIL

Abstract

This study investigated the feasibility of using agricultural wastes: Eggshell powder and fly-ashpowder for clay soil stabilization.The samples were mixed using seven trial mixes: 0%FA:18%ESP, 3%FA:15%ESP,6%FA:12%ESP, 9%FA :9%ESP, 12%FA:6%PLA, 15%FA:3%ESP, 18%FA:0%ESP and acontrol mix. Specific gravity, sieve analysis, Atterberg limits, compaction and Triaxial tests werecarried out.The clay soils were described as lean clay (UCSC). From the liquid limit results, on addition of3%FA :15%ESP, a visible reduction in the liquid limit values were observed, also on addition of6%FA:12%ESP, a reduction in values of the plastic index was documented in both soilsrespectively. Also, the addition of Eggshell powder alone significantly decreases atterberg limitvalues, while the addition of Fly-ash powder alone increases the values. The peak values for LL,PL and PI was obtained at 9%FA:9%ESP, 15%FA:3%ESP and 3%FA:15%ESP respectively.For compaction, 3%FA:15%ESP recorded the least MDD value with peak value at 15%FA:3%ESP in both samples. 15%FA:3%ESP yeilded the best shear strength in both EE1 and EE2. Interms of regressional analysis, EE2 yeilded the best P-value while EE1 yielded the least t-stat.From the R-square value and the Adjusted R-square value, it shows that the work follows analmost linear pattern or sequence and can be predicted perfectly with a linear with a linearequation.These findings reveal significant improvements in strength and index properties of the clay soil.In conclusion, eggshell powder and flyash produce an eco-friendly stabilizer that can be utilizedas subbase material in the stabilization of clay soils.