Yan Ziyue, Jiang Yaqing, Yin Kangting, Wang Limeng, Pan Tinghong
College of Mechanics and Materials, Hohai University, Nanjing 210098, China.
Key Laboratory of Disaster Reduction in Civil Engineering, Faculty of Civil Engineering and Mechanics, Kunming University of Science and Technology, Kunming 650500, China.
Materials (Basel). 2023 Oct 19;16(20):6762. doi: 10.3390/ma16206762.
This paper investigated the combined effect of chemical activators and nano-SiO on the hydration reaction and the microstructure of γ-CS. The hydration reaction of γ-CS slurry activated with chemical activators (NaHCO, NaOH, KCO, and KOH at 1 mol/L) was enhanced by 1% nano-SiO. The hydrate reaction rate was determined by isothermal calorimetry, and the hydrated samples were characterized by XRD, TGA/DTG, SEM-EDS, and Si MAS/NMR. The results revealed a substantial enhancement in the hydration activity of γ-CS due to the presence of the alkaline activator. Furthermore, nano-SiO did not alter the composition of γ-CS hydration products, instead providing nucleation sites for the growth of hydration products. Incorporating nano-SiO promoted the formation of C-(R)-S-H gel with a low calcium-to-silica ratio and increased its polymerization levels, resulting in more favorable structures. Among all the activators used in this study, potassium salts had a better activation effect than sodium salts. After 28 days of curing, the degree of hydration reaction in the KC+Si group was 48% and about 37% for the NHC+Si group. Whereas, the KH+Si and NH+Si groups only reached approximately 20% after the same hydration duration.
本文研究了化学活化剂与纳米二氧化硅对γ-CS水化反应及微观结构的联合作用。用1%纳米二氧化硅可增强用化学活化剂（1mol/L的NaHCO、NaOH、KCO和KOH）活化的γ-CS浆料的水化反应。通过等温量热法测定水合反应速率，并用XRD、TGA/DTG、SEM-EDS和Si MAS/NMR对水合样品进行表征。结果表明，由于碱性活化剂的存在，γ-CS的水化活性显著增强。此外，纳米二氧化硅没有改变γ-CS水化产物的组成，而是为水化产物的生长提供了成核位点。掺入纳米二氧化硅促进了低钙硅比C-(R)-S-H凝胶的形成并提高了其聚合水平，从而形成了更有利的结构。在本研究中使用的所有活化剂中，钾盐的活化效果优于钠盐。养护28天后，KC+Si组的水化反应程度为48%，NHC+Si组约为37%。而在相同水化时间后，KH+Si和NH+Si组仅达到约20%。
