Benkabouche Ali, Amar Mouhamadou, Benzerzour Mahfoud, Abriak Nor-Edine, T'kint Michèle, Mouli Mohamed
IMT Nord Europe, Institut Mines-Télécom, Centre des Matériaux et Procédés, 59000 Lille, France.
Research Unit Eco-Processes, Optimization, and Decision Support, Picardie Jules Verne University, 7 Street Moulin Neuf, 80000 Amiens, France.
Materials (Basel). 2023 Oct 13;16(20):6684. doi: 10.3390/ma16206684.
In France, the annual volume of dredged sediments is significantly increasing, which has become a real environmental problem. Nevertheless, these sediments can be used beneficially as supplementary cementing material. On the other hand, external sulfate attack is one of the most aggressive causes of deterioration that affects the durability of concrete structures. This study focused on the valorization of river-dredged sediments from Noyelles-Sous-Lens (Hauts-de-France) as a mineral addition in substitution of Portland cement, and it studied their impacts on the mechanical behavior and durability of reinforced mortars. X-ray diffraction (XRD) analysis indicated the presence of clay minerals in the raw sediment. In order to activate this clay fraction, flash calcination was applied at a temperature of 750 °C. In addition, four mixed mortars were formulated by mixing a Portland cement (CEM I 52.5 N) and the calcined sediments as a partial substitute for cement with proportions of 0%, 15%, 20%, and 30%, then stored in water tanks at room temperature (20 ± 2 °C) for 90 days in order to immerse them in a tank containing a 5% MgSO solution and to track the evolution of their corrosion potential as well as their mass variations every 20 days for a period of 360 days. The following additional tests were carried out on these mortars: tests of resistance to compression and flexion and to porosity by mercury intrusion. The results obtained from the majority of these tests showed that the mortar containing 15% calcined sediments is as effective and durable as the reference mortar itself. The main conclusion we can draw from these results is that the presence of these calcined sediments improves the overall behavior of the mortar.
在法国，疏浚沉积物的年总量正在显著增加，这已成为一个切实的环境问题。然而，这些沉积物可作为辅助胶凝材料加以有益利用。另一方面，外部硫酸盐侵蚀是影响混凝土结构耐久性的最具侵蚀性的劣化原因之一。本研究聚焦于法国上法兰西大区努瓦耶勒 - 苏 - 朗斯的河道疏浚沉积物作为矿物掺合料替代波特兰水泥的价值，并研究了它们对钢筋砂浆力学性能和耐久性的影响。X射线衍射（XRD）分析表明原始沉积物中存在粘土矿物。为了激活这一粘土部分，在750℃的温度下进行了快速煅烧。此外，通过将波特兰水泥（CEM I 52.5 N）与煅烧后的沉积物混合，配制了四种混合砂浆，以0%、15%、20%和30%的比例作为水泥的部分替代品，然后在室温（20±2℃）的水箱中存放90天，之后将其浸入含有5%硫酸镁溶液的水箱中，并在360天内每20天跟踪其腐蚀电位的变化以及质量变化。对这些砂浆还进行了以下额外测试：抗压和抗折强度测试以及压汞法孔隙率测试。这些测试中的大多数结果表明，含有15%煅烧沉积物的砂浆与参考砂浆本身一样有效且耐用。我们从这些结果中可以得出的主要结论是，这些煅烧沉积物的存在改善了砂浆的整体性能。
