This paper proposes that Ca²⁺ in steel slag (SS) has a weak early hydration activity when SS and granulated blast-furnace slag (GBFS) are used as alkali-activated cementitious materials. Herein, alkaline activators and Ca(OH)₂ are used as indicators of Ca²⁺ reaction in the SS and GBFS system. It is found that the 28-day compressive strength of the cementitious material with 2 wt% Ca(OH)₂ addition increased by 25.9% compared with the blank. Hydration products and microstructures were characterized by XRD, SEM/EDS, FTIR and TG/DTA. Results show that the addition of Ca(OH)₂ increased the content of active calcium ions in the reaction system, which promotes the reaction and the formation of C–S–H gel, resulting in an enhanced compressive strength ultimately. It can be also concluded that SS is not suitable as a sole precursor for the production of building materials on a large scale due to the weak early activity of Ca²⁺ in SS.

本文提出，当SS和粒状高炉渣（GBFS）用作碱活化胶凝材料时，钢渣（SS）中的Ca ²⁺具有较弱的早期水合作用。此处，碱性活化剂和Ca（OH）₂用作SS和GBFS系统中Ca ²⁺反应的指示剂。发现添加2重量％Ca（OH）₂的胶凝材料的28天抗压强度与空白相比增加了25.9％。通过XRD，SEM / EDS，FTIR和TG / DTA对水合产物和微结构进行了表征。结果表明，Ca（OH）_2的添加增加了反应体系中活性钙离子的含量，从而促进了反应和C–S–H凝胶的形成，最终提高了抗压强度。还可以得出结论，由于Ca ²⁺在SS中的早期活性较弱，因此SS不适合作为大规模生产建筑材料的唯一前体。