Unconfined Compressive Strength of Compacted Lateritic Soil Treated with Selected Admixtures for Geotechnical Applications
Authors: Sani JE, Yohanna P, Etim RK, Attah IC, Bayang F
The unconfined compressive strength (UCS) of treated lateritic soil was assessed using correlation and reliability analysis. The soil was admixed with groundnut shell ash (GSA) and sisal fibre (SF) included in varying percentage of 0 up to 8% of GSA and 0 up to 1% of SF by dry weight of soil. The SF was treated with Sodium Borohydride (NaBH4) (1%wt./vol.) to remove the cellulose present. Laboratory tests performed on the specimens included index properties, compaction test using British Standard Light and UCS test. Laboratory results were used to compute reliability indices using a FORTRAN based first order reliability program. The maximum dry density (MDD) decreased from 1.85Mg/m3 for the natural soil to 1.73 Mg/m3 at 0% GSA/1% SF content. Optimum moisture content (OMC) increased with GSA and SF addition. Correlation and reliability indices of the laboratory-based model shows that the independent parameters (GSA, SF, MDD and OMC) affect UCS with MDD and OMC having more effect. UCS increased from 101 kN/m2 for natural soil to optimum value of 696.41 kN/m2 at 0.75% SF/6%GSA content which met the minimum regulatory value for sub-base material and is recommended for use as sub-base material for rural roads.
Affiliations: Department of Civil Engineering, Faculty of Engineering, Akwa Ibom State University, Ikot Akpaden, Nigeria.
Keywords: Lateritic Soil, Sisal Fibre, Groundnut Shell Ash, Analysis Of Variance, Correlation Analysis, Reliability Index
Published date: 2019/12/30