To solve the energy consumption and CO₂ emission during cement production, the new binders must be developed as an alternative to cement. CaO/CaSO₄-activated slag binder is an eco-friendly and safe cementitious material; however, its low strength during initial stages limits its applications. In this study, colloidal nanosilica (CNS) was employed as an additive to improve the strength of CaO/CaSO₄-activated slag binder, and the effects of CNS on the workability, hydration kinetics, hydration products (type, quantity, and polymerization degree), and binder microstructure were thoroughly investigated. A moderate CNS content, through its nucleation effect, significantly increased the hydration rate of the nucleation and crystal growth (NG), phase boundary interaction (I) and diffusion (D) processes, which generated large quantities of calcium aluminosilicate hydrate (C-A-S-H) gel in the initial hydration stage. Meanwhile, the addition of CNS improved the polymerization degree of C-A-S-H gel. This amorphous reactant well-filled the pore space between slag particles and yielded a compact microstructure, consequently enhancing the binder strength. Considering the reduction in fluidity and the increase in production cost, the CNS mass fraction was controlled as ∼3%, and the binder reached the satisfactory strengths of 3.87, 24.47, 31.43, and 41.78 MPa at 1, 3, 7, and 28 d, respectively.

为了解决水泥生产过程中的能源消耗和CO ₂排放问题，必须开发新型粘结剂作为水泥的替代品。CaO/CaSO ₄活化矿渣结合剂是一种环保、安全的胶凝材料；然而，它在初始阶段的低强度限制了它的应用。在这项研究中，胶体纳米二氧化硅 (CNS) 被用作添加剂来提高 CaO/CaSO _4的强度-活化矿渣粘合剂，以及 CNS 对和易性、水化动力学、水化产物（类型、数量和聚合度）以及粘合剂微观结构的影响。适量的 CNS 含量，通过其成核作用，显着提高了成核和晶体生长 (NG)、相界相互作用 (I) 和扩散 (D) 过程的水化速率，从而生成大量铝硅酸钙水合物 (CASH) 凝胶在最初的水合作用阶段。同时，CNS的加入提高了CASH凝胶的聚合度。这种无定形反应物很好地填充了渣粒之间的孔隙空间，并产生了致密的微观结构，从而提高了粘结剂强度。考虑到流动性的降低和生产成本的增加，