International Science Community Association Research Journal of Engineering Sciences 14 3 2025 09 26 Influence of limestone and bagasse ash on the physical and mechanical characteristics of a clay soil stabilized with sugar cane molasses 1 14 EN MANIONGUI Kris Berjovie 1 Energy and Engineering, Laboratory of Mechanics, Higher National Polytechnic Institute, Marien NGOUABI University, P.O. Box: 69 – Brazzaville, Republic of the Congo NGOUALLAT Nice Mfoutou 2 Energy and Engineering, Laboratory of Mechanics, Higher National Polytechnic Institute, Marien NGOUABI University, P.O. Box: 69 – Brazzaville, Republic of the Congo and National Institute for Research in Engineering Sciences, Innovation, and Technology (INRSIIT), Brazzaville, Republic of the Congo Malanda Christ Ariel Ceti 3 Energy and Engineering, Laboratory of Mechanics, Higher National Polytechnic Institute, Marien NGOUABI University, P.O. Box: 69 – Brazzaville, Republic of the Congo MOUNDZA Debora 4 Energy and Engineering, Laboratory of Mechanics, Higher National Polytechnic Institute, Marien NGOUABI University, P.O. Box: 69 – Brazzaville, Republic of the Congo MALANDA Narcisse 5 Energy and Engineering, Laboratory of Mechanics, Higher National Polytechnic Institute, Marien NGOUABI University, P.O. Box: 69 – Brazzaville, Republic of the Congo and Building Planning and Public Works, Higher Institute of Architecture, DENIS SASSOU NGUESSO University, Kintélé, Republic of the Congo > Research Paper 2024 11 27 2025 09 26 This treaty was carried out as part of the clay stabilization for better use in road works. Limestone (4%; 6% and 8%) and bagasse ash (4%; 6% and 8%) were added to the clay soil stabilized at 8% sugarcane molasses on the one hand. then a combination of the two admixtures (4%Ca +4%Ba; 6%Ca+6%Ba and 8%Ca+8%Ba) was used. The analysis of the influence of these admixtures on the physico-mechanical behaviour of this soil has shown that: the mechanical compressive and tensile strengths are interesting for all formulations for limestone. The percentage of 8% limestone gives more gain in compressive strength (4.65 MPa) and tensile strength (1.2 MPa). The addition of bagasse ash does not provide any gains in compressive and tensile strength in this soil. The optimal percentage of bagasse ash is 4%. The combination of bagasse ash (8%) and limestone (8%) slightly increases the compressive (2 MPa) and tensile strength (0.9 MPa) of this soil: compression (1.85 MPa), tensile strength (0.8 MPa). However, there is a decrease in compressive and tensile strength compared to molasses and limestone-stabilized samples. The addition of 6% limestone reduces water absorption (2.96%) in this soil (5.27%). The addition of 6% of sugarcane bagasse ash contributes to the decrease in water absorption (3.58%) of this soil (5.27%). The combination of bagasse ash (6%) and limestone (6%) does not reduce water absorption. The addition of limestone (6%) reduces the porosity (4.47%) of this soil (6.75%). The addition of bagasse ash (6%) reduces the porosity (4.56%) of this soil (6.75%). The combination of bagasse ash (6%) and limestone (6%) reduces the porosity (4.96%) of this soil (6.75%). We can say that limestone improves the physico-mechanical properties of the soil stabilized by sugar cane molasses. Sugarcane bagasse ash must be added through limestone to stabilize clay soil using molasses. Copyright@ International Science Community Association