Statkauskas Martynas, Vaičiukynienė Danutė, Grinys Audrius
Faculty of Civil Engineering and Architecture, Kaunas University of Technology, Studentų g. 48, 44249, Kaunas, Lithuania.
Sci Rep. 2024 Jun 6;14(1):13060. doi: 10.1038/s41598-024-63808-z.
These days, the construction industry is facing sustainability issues, leading to the selection of greener, low-carbon, alkali-activated materials. This study examines a low calcium alkali activated system composed of three constituents (ceramic brick, metakaolin waste, and phosphogypsum). The AAB compositions consist of the primary precursor, waste ceramic brick, which is increasingly (20-100 wt%) replaced with waste metakaolin. The alkaline solution was made of sodium hydroxide and water; dosage depended on the NaO/AlO ratio (1.00-1.36). The AAB specimens were inspected by using XRD (X-ray diffraction) and FT-IR (Fourier transform infrared spectroscopy) methods for the evaluation of mineral composition, accompanied by SEM-EDS (scanning electron microscopy & energy dispersive X-ray spectroscopy) for the analysis of the microstructure. The compressive strength after 7, 28 and 90 days, along with water absorption and softening coefficient were determined. Also, mixture calorimetry was established. The results have shown that the initial materials are suitable for producing medium-strength alkali-activated binder under ambient temperature. The maximum compressive strength was reached by using the combination of 80% CBW and 20% MKW (13.9 and 21.2 MPa after 28 and 90 days respectively). The compressive strength development was linked with the formation N-A-S-H gel and faujasite type zeolite. A higher level of geopolymerization in composition with metakaolin waste led to lower compressive strength. Consequently, binding materials with low demand of high final and especially early compressive strength could be produced under ambient temperature curing, making them more sustainable.
如今，建筑业正面临可持续发展问题，这导致人们选择更环保、低碳的碱激活材料。本研究考察了一种由三种成分（陶瓷砖、偏高岭土废料和磷石膏）组成的低钙碱激活体系。碱激活粘结剂（AAB）的成分包括主要前驱体废陶瓷砖，其被偏高岭土废料替代的比例逐渐增加（20 - 100 wt%）。碱性溶液由氢氧化钠和水制成；用量取决于NaO/AlO比（1.00 - 1.36）。通过XRD（X射线衍射）和FT - IR（傅里叶变换红外光谱）方法对AAB试样进行检测，以评估矿物成分，同时采用SEM - EDS（扫描电子显微镜和能量色散X射线光谱）分析微观结构。测定了7天、28天和90天后的抗压强度以及吸水率和软化系数。此外，还建立了混合量热法。结果表明，这些初始材料适合在常温下生产中等强度的碱激活粘结剂。使用80%陶瓷砖废料（CBW）和20%偏高岭土废料（MKW）的组合可达到最大抗压强度（28天和90天后分别为13.9 MPa和21.2 MPa）。抗压强度的发展与N - A - S - H凝胶和八面沸石型沸石的形成有关。偏高岭土废料组成中较高水平的地质聚合导致抗压强度较低。因此，在常温养护条件下可以生产出对最终抗压强度尤其是早期抗压强度要求较低的粘结材料，使其更具可持续性。
