Oti Jonathan, Adeleke Blessing O, Anowie Francis X, Kinuthia John M, Ekwulo Emma
Faculty of Computing, Engineering and Science, University of South Wales, Pontypridd CF37 1DL, UK.
Department of Civil Engineering, Faculty of Engineering, Rivers State University, Porth Harcourt PMB 5080, Nigeria.
Materials (Basel). 2024 Apr 13;17(8):1792. doi: 10.3390/ma17081792.
A geopolymer is an inorganic amorphous cementitious material, emerging as an alternative sustainable binder for greener concrete production over Ordinary Portland Cement (OPC). Geopolymer concrete production promotes waste reuse since the applicable precursor materials include agricultural and industrial waste that requires disposal, helping to reduce waste in landfills and ensuring sustainable environmental protection. This study investigates the development of an environmentally friendly sodium silicate alternative (SSA) derived from pumice powder (PP) in place of a commercial NaSiO solution at a 10 M concentration. Six concrete batches were produced at alkaline/precursor (A/P) ratios of 0.1, 0.2, 0.3, 0.4, and 0.5. The geopolymer mix AF4, with an A/P ratio of 0.4, became the optimum geopolymer concrete design; however, it recorded lower compressive, tensile splitting, and flexural strengths, respectively, against the control OPC concrete. The geopolymer formulations, however, obtained 28-day-hardened concrete densities comparable to the control concrete. The 28-day compressive strength of the OPC concrete was 29.4 MPa, higher than the 18.8 MPa recorded for AF4. However, the 56-day strength of AF4 improved to 22.4 MPa, an around 19% increase compared to the 30.8 MPa achieved by the control mix on day 56, having experienced only a 5% strength increase. The low mechanical performances of the geopolymer formulation could be attributed to extra water added to the original geopolymer design to improve the workability of the geopolymer mix. Therefore, the SSA alkaline solution using PP showed some potential for developing geopolymer concrete for low-strength construction applications.
地质聚合物是一种无机无定形胶凝材料，作为一种替代的可持续粘结剂出现，用于生产比普通硅酸盐水泥（OPC）更环保的混凝土。地质聚合物混凝土的生产促进了废物再利用，因为适用的前驱体材料包括需要处理的农业和工业废物，有助于减少垃圾填埋场的废物，并确保可持续的环境保护。本研究调查了一种由浮石粉（PP）衍生的环保型硅酸钠替代品（SSA）的开发，以替代浓度为10M的商业硅酸钠溶液。以0.1、0.2、0.3、0.4和0.5的碱/前驱体（A/P）比生产了六批混凝土。A/P比为0.4的地质聚合物混合料AF4成为最佳地质聚合物混凝土设计；然而，与对照OPC混凝土相比，它的抗压强度、劈裂抗拉强度和抗弯强度分别较低。然而，地质聚合物配方获得的28天硬化混凝土密度与对照混凝土相当。OPC混凝土的28天抗压强度为29.4MPa，高于AF4记录的18.8MPa。然而，AF4的56天强度提高到22.4MPa，与对照混合料在56天时达到的30.8MPa相比增加了约19%，而对照混合料仅增加了5%的强度。地质聚合物配方的低力学性能可能归因于在原始地质聚合物设计中添加了额外的水以改善地质聚合物混合料的工作性。因此，使用PP的SSA碱性溶液在开发用于低强度建筑应用的地质聚合物混凝土方面显示出一些潜力。
