Supersulfated cement (SSC) is a traditional low-carbon cement, but its slow hydration and strength development has limited its practical applications. Nano silica (NS) was used to activate the hydration of SSC by taking advantage of its ability to regulate silicate and aluminate reactions. The mechanical performance of various mixes was determined, as a function of sulfation degree and NS addition, as pore structure, phase assemblage, hydration degree, and microstructure. Results showed that NS improves the hydration degree of slag, densifies the microstructure, and significantly increases both early- and late-age compressive strength. The enhancement was attributed to its effects on the hydration of slag in SSC: delaying ettringite formation, but promoting C-(A)-S-H precipitation, reducing microporosity. This study reveals the critical role of the regulation of hydration kinetics of silicate and aluminate in controlling the performance of SSC as NS does.
The authors gratefully acknowledge support from National Natural Science Foundation of China (52102021), National Natural Science Foundation of China Regional Innovation and Development Joint Fund (U22A20126), Shandong Province Natural Science Foundation (ZR2021QE058, ZR2020YQ33), Department of Education of Shandong Province (2019GGX102077), Science and Technology Innovation Support Plan for Young Researchers in Institutes of Higher Education in Shandong (2019KJA017). This project has also received funding from the European Union’s Horizon 2020 - Research and Innovation Framework Programme under the H2020 Marie Skłodowska-Curie Actions grant agreement No , and funding from Youth Innovation Support Program of Shandong Colleges and Universities, which is also appreciated.
Copyright © 2023 Elsevier Ltd. All rights reserved.
- supersulfated cement
- nano silica
- gypsum content
- mechanical property