Joseph Shiju, Cizer Özlem
Materials and Construction, Department Civil Engineering, KU Leuven, 3001 Brussels, Belgium.
Materials (Basel). 2022 Mar 4;15(5):1914. doi: 10.3390/ma15051914.
Replacement of Portland cement with high volumes of blast furnace slag is known to negatively affect the early-age properties of concrete, particularly at low temperatures. In this study, the effectiveness of NaSO on the mechanical properties, hydration kinetics and microstructure development of a commercial CEM III/B (~69% slag) is investigated at 10 and 20 °C. NaSO enhances compressive strength at both 10 and 20 °C, and at both early (1 and 7 days) and later ages (28 and 90 days). QXRD shows an increase in the degree of alite hydration at 1 day with NaSO addition, while the degree of clinker and slag hydration is similar for all the systems from 7 to 90 days. An increase in ettringite content is observed at all ages in the systems with NaSO. Microstructure and pore structure shows densification of hydrates and reduction in porosity on addition of NaSO.
众所周知，用大量高炉矿渣替代波特兰水泥会对混凝土的早期性能产生负面影响，尤其是在低温情况下。在本研究中，研究了硫酸钠（NaSO）对一种商用CEM III/B（约69%矿渣）在10℃和20℃时的力学性能、水化动力学和微观结构发展的影响。硫酸钠在10℃和20℃时均能提高抗压强度，且在早期（1天和7天）和后期（28天和90天）均有此效果。定量X射线衍射（QXRD）表明，添加硫酸钠后1天的阿利特水化程度有所增加，而从7天到90天，所有体系的熟料和矿渣水化程度相似。在添加硫酸钠的体系中，各龄期的钙矾石含量均有所增加。微观结构和孔隙结构表明，添加硫酸钠后水化物致密化，孔隙率降低。
