Abstract This study investigates the effect of NaOH content on alkali/sulfate-activated binders from 90 wt% ground granulated blast furnace slag (GGBFS) and 10 wt% phosphogypsum (PG). Alkali activators were prepared with a NaOH molarity ranging from 0 M to 4 M. The hydration was monitored using in-situ X-ray diffraction (XRD) and isothermal calorimetry. The hydration product assemblage was investigated using XRD, thermogravimetric analysis (TGA), Fourier-transformed infrared (FTIR) spectroscopy, nitrogen adsorption/desorption and compressive strength tests. A molarity of 0 M NaOH gave rise to the highest porosity and highest strength, although setting occurred only after 7 days. From a molarity of 2 M NaOH and higher, ettringite disappeared and got replaced by a monosulfate phase (i.e., NaCa4Al2O6(SO4)1.5.15H2O) and amorphous aluminum-hydroxide. This study shows the potential of using GGBFS and PG for the development of novel by-product based cementitious binders.

中文翻译：

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NaOH 含量对高炉粒化矿渣和磷石膏中碱/硫酸盐活化粘合剂的水化、矿物学、孔隙率和强度的影响

摘要 本研究调查了 NaOH 含量对来自 90 wt% 磨碎粒状高炉矿渣 (GGBFS) 和 10 wt% 磷石膏 (PG) 的碱/硫酸盐活化粘合剂的影响。用 0 M 至 4 M 的 NaOH 摩尔浓度制备碱活化剂。使用原位 X 射线衍射 (XRD) 和等温量热法监测水合。使用XRD、热重分析(TGA)、傅里叶变换红外(FTIR)光谱、氮吸附/解吸和抗压强度测试来研究水合产物组合。0 M NaOH 的摩尔浓度产生最高的孔隙率和最高的强度，尽管凝固仅在 7 天后发生。从 2 M NaOH 和更高的摩尔浓度开始，钙矾石消失并被单硫酸盐相（即 NaCa4Al2O6(SO4)1.5.15H2O）和无定形氢氧化铝取代。