Effect of Groundnut Shell Ash on Laterite Soils Stabilized with Lime for Civil Structures

Abstract

This study considered the practicality of groundnut shell ash (GSA) on laterite stabilized with lime for civil structures. Three site locations of lateritic soil named specimen I, II and III were assembled from Ifewara, Atakunmosa West Local Government Area, Ilesa East Local Government Area, and Ilesa West Local Government, all situated in Osun State, Nigeria. Preliminary tests were wrapped up on the soil specimens in their characteristic states and when stabilized with optimum lime. Compaction, California Bearing Ratio (CBR) and undrained triaxial shear strength tests were performed when fluctuating paces of 2 %, 4 %, 6 %, and 8 % of GSA were included to the soil specimens at optimum lime. The Atterberg limits tests showed a critical decrease in plasticity index for all the soil specimens when stabilized with lime. Compaction test showed a lessening in the maximum dry density from 1732 kg/m3 to 1651 kg/m3 for specimen I, 1874 kg/m3 to 1621 kg/m3 for specimen II and 1683 kg/m3 to 1655 kg/m3 for specimen III on stabilizing with lime, presentation of GSA to stabilized lime-soil decreases the maximum dry density for all the soil specimen with specimen I diminished to 1642 kg/m3, 1595 kg/m3, 1611 kg/m3 and 1611 kg/m3 at 2 %, 4 %, 6 % and 8 % GSA substances individually. Addition of GSA substances enhanced the engineering properties of laterite stabilized with lime as the unsoaked CBR values expanded for all the soil specimens. At optimum lime measurements, addition of 4 % GSA expanded the shear strength to 110.74 kN/m2 and 127.53 kN/m2 for specimens I and II individually while at 6 % GSA addition, the shear strength of specimen III was peak 118.24 kN/m2. The expansion in shear strength further affirms the improvement prior shown in the geotechnical properties of lateritic soil with the addition of groundnut shell ash. addition of 2 % GSA content extended the triaxial shear strength from 60.43kN/m2 to 188.36kN/m2 for specimen I, and at 4% GSA content, both soil specimens II and III expanded from 19.19kN/m2 to 201.48kN/m2 and 30.62kN/m2 to 111.65kN/m2 separately. Conclusively, GSA improved the durability and strength of lateritic soils stabilized with lime for civil structures.