Han Fanghui, Zhu Ziqin, Zhang Hongbo, Li Yuchen, Fu Ting
Beijing Key Laboratory of Urban Underground Space Engineering, School of Civil and Resource Engineering, University of Science and Technology Beijing, Beijing 100083, China.
Research Institute of Urbanization and Urban Safety, University of Science and Technology Beijing, Beijing 100083, China.
Materials (Basel). 2024 May 22;17(11):2495. doi: 10.3390/ma17112495.
Slag and fly ash (FA) are mostly used as precursors for the production of alkali-activated materials (AAMs). FA is the waste discharged by power plants, while slag and steel slag (SS) both belong to the iron and steel industry. The effects of SS and FA on the strength, microstructure, and volume stability of alkali-activated slag (AAS) materials with different water glass modulus (Ms) values were comparatively investigated. The results show that adding SS or FA decreases the compressive strength of AAS mortar, and the reduction effect of SS is more obvious at high Ms. SS or FA reduce the non-evaporable water content (W) of AAS paste. However, SS increases the long-term W of AAS paste at low Ms. The cumulative pore volume and porosity increase after adding SS or FA, especially after adding FA. The hydration products are mainly reticular C-(A)-S-H gels. Adding SS increases the Ca/Si ratio of C-(A)-S-H gel but decreases the Al/Si ratio. However, by mixing FA, the Ca/Si ratio is reduced and the Al/Si ratio is almost unchanged. The incorporation of SS or FA reduces the drying shrinkage of AAS mortar, especially when SS is added. Increasing Ms increases the compressive strength and improves the pore structure, and it significantly increases the drying shrinkage of all samples. This study provides theoretical guidance for the application of steel slag in the alkali-activated slag material.
矿渣和粉煤灰（FA）大多用作制备碱激发材料（AAMs）的前驱体。粉煤灰是发电厂排放的废弃物，而矿渣和钢渣（SS）都属于钢铁行业。对比研究了钢渣和粉煤灰对不同水玻璃模数（Ms）值的碱激发矿渣（AAS）材料强度、微观结构和体积稳定性的影响。结果表明，添加钢渣或粉煤灰会降低AAS砂浆的抗压强度，在高Ms值时钢渣的降低作用更明显。钢渣或粉煤灰会降低AAS浆体的非蒸发水含量（W）。然而，在低Ms值时钢渣会增加AAS浆体的长期非蒸发水含量。添加钢渣或粉煤灰后，累计孔隙体积和孔隙率增加，尤其是添加粉煤灰后。水化产物主要是网状C-(A)-S-H凝胶。添加钢渣会提高C-(A)-S-H凝胶的Ca/Si比，但会降低Al/Si比。然而，通过掺入粉煤灰，Ca/Si比降低，Al/Si比几乎不变。掺入钢渣或粉煤灰会降低AAS砂浆的干燥收缩，尤其是添加钢渣时。增加Ms值会提高抗压强度并改善孔隙结构，且会显著增加所有样品的干燥收缩。本研究为钢渣在碱激发矿渣材料中的应用提供了理论指导。
