Mbengue Marie Thérèse Marame, Lawane Gana Abdou, Messan Adamah, Mone Ousseni, Pantet Anne
Laboratoire Eco-Matériaux et Habitats Durables (LEMHaD), Institut International d'Ingénierie de l'Eau et de l'Environnement (2iE), 1, Rue de la Science, Ouagadougou 01 BP 594, Burkina Faso.
Laboratoire Ondes et Milieux Complexes (LOMC), Université Le Havre Normandie, UMR 6294 CNRS, 76063 Le Havre, France.
Materials (Basel). 2023 Oct 27;16(21):6891. doi: 10.3390/ma16216891.
In Burkina Faso, the most commonly used road construction material is lateritic soil. However, in its raw state, this soil does not meet the required recommendations. To overcome this problem, previous studies have often focused on improving these soils by adding cement. However, these studies have rarely included a multi-criteria characterisation of the main geomechanical parameters of treated soils. It was also noted that the identification parameters of lateritic soils could have an influence on their improvement with cement. The aim of this study is to highlight the influence of the physical and mineralogical properties of lateritic soils on the effectiveness of improving their geomechanical properties by adding a low content of cement (<3% wt.). The soils were taken from two sites: Saaba (LAS) and Kamboinsé (LAK). The effects of cement addition on the plasticity index, CBR index, Young's modulus, unconfined compressive strength, tensile strength and shear strength were studied. In their raw state, LAS and LAK have different physical properties and cannot be used as sub-bases. The addition of cement improves the overall physical and mechanical properties of both soils, but to different degrees. Indeed, after adding 3% cement to the raw soils, the CBR index of LAS increases by 1275% compared with 257% for LAK; the unconfined compressive strength of LAS is twice as high as that of LAK, and the Young's modulus increases by around 460% for LAS compared with 360% for LAK. After improvement, these two soils met all the CEBTP specifications except for tensile strength. The effect of cement was more significant on LAS due to its better physical properties and higher clay mineral content, which would improve pozzolanic reactivity during cement hydration. Knowing the mineralogy of lateritic soils when treating them with cement would allow us to reduce the quantity of cement, thereby mitigating its negative impact on the environment.
在布基纳法索，最常用的道路建设材料是红土。然而，这种土壤处于原始状态时并不符合所需的建议标准。为克服这一问题，以往的研究通常侧重于通过添加水泥来改良这些土壤。然而，这些研究很少对处理后土壤的主要地质力学参数进行多标准表征。还注意到，红土的识别参数可能会对其水泥改良效果产生影响。本研究的目的是突出红土的物理和矿物学性质对通过添加低含量水泥（<3%重量）改善其地质力学性质有效性的影响。土壤取自两个地点：萨阿巴（LAS）和坎博因塞（LAK）。研究了添加水泥对塑性指数、加州承载比（CBR）指数、杨氏模量、无侧限抗压强度、抗拉强度和抗剪强度的影响。LAS和LAK在原始状态下具有不同的物理性质，不能用作底基层。添加水泥改善了两种土壤的整体物理和力学性质，但程度不同。事实上，在原始土壤中添加3%水泥后，LAS的CBR指数比LAK增加了1275%，而LAK仅增加了257%；LAS的无侧限抗压强度是LAK的两倍，LAS的杨氏模量比LAK增加了约460%，而LAK增加了360%。改良后，除抗拉强度外，这两种土壤均符合法国公共工程研究与技术中心（CEBTP）的所有规范。由于LAS具有更好的物理性质和更高的粘土矿物含量，水泥对其的效果更为显著，这将改善水泥水化过程中的火山灰反应活性。在用水泥处理红土时了解其矿物学情况，将使我们能够减少水泥用量，从而减轻其对环境的负面影响。
