Rock wool, as an external wall insulation material, is crucial in improving the energy efficiency of structures. However, a large amount of rock wool furnace slag (RWFS) generated during the production of rock wool panels manufacturing causes environmental problems. To address these issues, this study focuses on the use of waste RWFS as a precursor in alkali-activated cementitious materials. In addition, the effect of anatase nano-TiO2 (ANT) and rutile nano-TiO2 (RNT) as an additive to the alkali-activated rock wool furnace slag cementitious materials (AARWFSCMs) was evaluated and quantified. Scanning Electronic Microscope (SEM), Isothermal Conduction Calorimetry (ICC), Fourier-Transform Infrared Spectroscopy (FT-IR), X-ray diffraction (XRD) analysis were used to identify the effects of modulus 1.0–1.8 water glass modulus (Ms; SiO2/Na2O), 3%–7% Na2O content on AARWFSCMs. Experimental tests was conducted to quantify the properties such as the setting time, the fluidity, the compressive strength of AARWFSCMs after hardening. Results found that the optimal content of Ms, Na2O content in preparing AARWFSCM were 1.4, 5 % for obtaining 28-d compressive strength of 96.36 MPa. The atomic percentage of Ca/Si of the hydration products in the AARWFSCMs fluctuated within 0.94–1.50. The hydration products were a mixture of C–S–H and C–A–S–H. Moreover, the experimental results illustrated that the nano-TiO2, which highly beneficial in improving the compressive strength of AARWFSCMs. The additions of 0.50 % ANT and 0.75 % RNT resulted in increments of 5.9 % and 12.8 % in the 28-d compressive strength of AARWFSCMs, respectively. The obtained results provide a new method of utilization of RWFS and improving the sustainability of the construction industry.

中文翻译：

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岩棉炉渣的碱活化：水玻璃模量、Na2O 含量和纳米 TiO2 的影响


岩棉作为一种外墙保温材料，对于提高结构的能源效率至关重要。然而，岩棉板制造过程中产生的大量岩棉炉渣 （RWFS） 会导致环境问题。为了解决这些问题，本研究的重点是在碱活化胶凝材料中使用废弃 RWFS 作为前驱体。此外，还评价和量化了锐钛矿纳米 TiO2 （ANT） 和金红石纳米 TiO2 （RNT） 作为碱活化岩棉炉渣胶凝材料 （AARWFSCMs） 添加剂的效果。采用扫描电子显微镜 （SEM）、等温传导量热法 （ICC）、傅里叶变换红外光谱 （FT-IR）、X 射线衍射 （XRD） 分析确定模量 1.0–1.8 水玻璃模量 （Ms;SiO2/Na2O），AARWFSCM 上 Na2O 含量为 3%–7%。进行了实验测试以量化硬化后 AARWFSCM 的凝固时间、流动性、抗压强度等性能。结果表明，制备 AARWFSCM 时 Ms、Na2O 含量的最佳含量为 1.4、5 %，28 d 抗压强度为 96.36 MPa。AARWFSCM 中水合产物的 Ca/Si 原子百分比在 0.94-1.50 之间波动。水合产物是 C-S-H 和 C-A-S-H 的混合物。此外，实验结果表明，纳米 TiO2 对提高 AARWFSCMs 的抗压强度非常有益。添加 0.50% ANT 和 0.75% RNT 导致 AARWFSCM 的 28 天抗压强度分别增加了 5.9% 和 12.8%。获得的结果提供了一种利用 RWFS 和提高建筑业可持续性的新方法。