Geotechnical characterization and behaviour of cement and lime -stabilized expansive soils in Awka and environs, South Eastern Nigeria
Date
2020-02
Authors
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Journal ISSN
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Publisher
Federal University of Technology, Owerri
Abstract
This study was undertaken to ascertain the geotechnical properties of the expansive soils responsible for the swelling potential and degree of expansion of the studied soils in Awka and environs Southeastern Nigeria. A total of eight (8) expansive soils were collected at different locations of the studied area and the geotechnical properties analyzed in the laboratory includes; grain size, Atterberg limit test, linear shrinkage, natural moisture content, free swell, compaction test, CBR test, specific gravity, dry and bulk density. Results of the study revealed a high to very high swelling potentials using the liquid limit (63.10 to 77.40%), plasticity index values (31.48 to 46.45%) and medium to high activity using activity values (0.98 to 1.55%). A critical and high degree of expansion was observed with linear shrinkage (10.70 to 20.00%) and free swell values (53.00 to 71.00%) respectively. In addition, low strength characteristics of the studied soils were similarly observed with the unsoaked (10.20 to 18.10%) and soaked (1.90 to 3.30%) CBR values, the optimum moisture content values (17.70 to 27.00%) and maximum dry density values (1.40 to 1.75Mg/m3 ). The Grain size analysis revealed that the studied soils are poorlygraded material with percentages passing the No.200 BS (62.10 to 94.80%) and can be classified as CH soils (fat clays) when plotted on a Casagrande plasticity chart. After stabilizing the studied soils with different proportions of cement and lime (2 to 10%), there were reductions in the swelling potential, degree of expansion and increase in the strength characteristics and durability of the soils. The optimum (minimum LL and PI values) values of the swelling indicators were achieved at 6% and 8% of lime and cement additives respectively. Soil stabilization with lime performs better than cement because lime has adverse effects on the swelling potential of a soil than cement but cement performs better when strength characteristics of the soil is the criteria.
Description
This work is for the award of the degree of Master of Science (MSc) in Environmental Geology
Keywords
Expansive soils, swelling potential, Atterberg limit, degree of expansion, road failure, strength characteristics., Department of Geology
Citation
Ogbuchukwu, P. O. (2020) Geotechnical characterization and behaviour of cement and lime -stabilized expansive soils in Awka and environs, South Eastern Nigeria{unpublished}