Open Journal of Civil Engineering, 2020, 10, 22-31 https://www.scirp.org/journal/ojce ISSN Online: 2164-3172 ISSN Print: 2164-3164 DOI: 10.4236/ojce.2020.101003 Jan. 31, 2020 22 Open Journal of Civil Engineering Improvement of the Geotechnical Properties of the Soil of Lime-Treated Cubitermes Mound Soil Séverin Jean Maixent Loubouth 1,2 , Louis Ahouet 1,3 , Raymond Gentil Elenga 1* , Sylvain Ndinga Okina 1,2 , Paul Louzolo Kimbembe 4 1 Laboratoire des Matériaux et Energies, Faculté des Sciences et Techniques, Université Marien Ngouabi, Brazzaville, Congo 2 Ecole Nationale Supérieure Polytechnique, Université Marien Ngouabi, Brazzaville, Congo 3 Bureau de Contrôle du Bâtiment et Travaux Publics, Brazzaville, Congo 4 Ecole Normale Supérieure, Université Marien Ngouabi, Brazzaville, Congo Abstract This work consisted in determining the geotechnical properties of the soil of the Cubitermes termite mound soil treated with lime for use in road con- struction in accordance with the relevant standards. The raw soil is composed of 29.45% clay, 45.12% silt and 25.43% sand, and its granulometric curve is above the relevant standard curve. The addition of lime up to 9% decreases the fine fraction content from 75% to 60%, and the maximum dry density from 1.62 t/m 3 to 1.36 t/m 3 . The reduction of the fine fraction should reduce the soil sensitivity to water, and the emission of dust from the road. The compressive strength of the raw soil (3.89 MPa) is higher than that of most cohesive soil, and is probably one the causes of the longevity of the rural road paved with this soil. Treated soil with 6% in lime content has the highest compressive strength (5.95 MPa), and the lowest deformation at failure. Until 28 days, the improvement of the compressive upon the curing time is almost the same for untreated and treated termite mound soils. Thus, this improve- ment could be mostly attributed to the drying of the samples instead to the pozzolanic reactions. Besides, adding lime also enhances the shear strength of soil. Therefore, adding lime up to 6% in content to the termite mound soil should improve its behavior as surface roads. Keywords Cubitermes Mound Soil, CEBTP 1980, Unpaved Roads, Geotechnical Properties How to cite this paper: Loubouth, S.J.M., Ahouet, L., Elenga, R.G., Okina, S.N. and Kimbembe, P.L. (2020) Improvement of the Geotechnical Properties of the Soil of Lime-Treated Cubitermes Mound Soil. Open Journal of Civil Engineering, 10, 22-31. https://doi.org/10.4236/ojce.2020.101003 Received: November 9, 2019 Accepted: January 28, 2020 Published: January 31, 2020 Copyright © 2020 by author(s) and Scientific Research Publishing Inc. This work is licensed under the Creative Commons Attribution International License (CC BY 4.0). http://creativecommons.org/licenses/by/4.0/ Open Access