C-S-H纳米晶种及其对水泥水化硬化的促进作用综述  

C-S-H Nano-seed and Its Promoting Effect on Cement Hydration and Hardening:a Review

作　　者：唐芮枫 张佳乐 王子明[1] 崔素萍[1] 王肇嘉 兰明章[1] TANG Ruifeng;ZHANG Jiale;WANG Ziming;CUI Suping;WANG Zhaojia;LAN Mingzhang(College of Materials Science and Engineering,Beijing University of Technology,Beijing 100124,China;State Key Laboratory of Soild Waste Utilization and Energy,Saving Building Materials,Beijing Building Materials Research Institute Co.,Ltd.,Beijing 100041,China)

机构地区：[1]北京工业大学材料与制造学部,北京100124 [2]北京建筑材料科学研究总院有限公司固废资源化利用与节能建材国家重点实验室,北京100041

出　　处：《材料导报》2023年第9期105-120,共16页Materials Reports

基　　金：北京市自然科学基金-市教委联合资助项目(KZ202010005013)。

摘　　要：近些年来的研究发现,将一些纳米粒子加入到水泥中,可以为水化产物提供更多形核位点,降低水化产物的形核势垒,加快水泥的水化进程。这些纳米材料包括纳米SiO_(2)、纳米CaCO_(3)、纳米TiO_(2)、碳纳米管、纳米水化硅酸钙(C-S-H)等。其中,人工合成的纳米C-S-H晶种与水泥水化产物C-S-H凝胶具有相似的化学组成,是C-S-H凝胶的良好的形核基质,在众多晶种材料中,对水泥水化的加速作用最为显著,成为近年来的研究热点。到目前为止,众多学者围绕C-S-H微/纳米材料的成核方式、制备方法及对水泥水化的促进机理进行了大量研究,发现采用共沉淀法在聚合物存在的条件下制备的纳米C-S-H晶种成核剂遵循非经典成核方式,其具有纳米级的晶粒尺寸和良好的分散稳定性。将纳米C-S-H晶种以一定掺量加入到水泥中,可以充当水泥水化产物C-S-H凝胶的额外成核位点,极大地降低了C-S-H凝胶的成核势垒,有效地促进了水泥水化速率和早期强度的发展,尤其可以显著提升水泥1 d龄期以内的强度。与常用的早强剂相比,这种纳米C-S-H晶种成核剂除具有掺量低、早强效果好、对水泥混凝土耐久性无不利影响的优点外,还可以在一定程度上弥补辅助性胶凝材料(SCMs)早期强度增长缓慢的问题。因此,纳米C-S-H晶种在低温施工、滑模施工、预制混凝土制品生产等对早期强度要求较高的工程中具有良好的应用前景,有潜力成为水泥混凝土的新型早强剂。本文尝试对众多研究成果进行总结分析,从纳米C-S-H晶种的成核方式、制备方法、与聚合物的作用机理以及对水泥水化过程的影响等方面进行综述,在明确现有的规律和成果的基础上,分析了目前存在的不足,得出尚待继续研究的问题,以期为未来纳米C-S-H晶种的科学研究、工程应用提供理论基础和发展方向。In recent years,several nanoparticles have been studied as potential nucleation seeds for cement hydration.Synthetic nano-calcium silicatehydrate(C-S-H),nano-SiO_(2),nano-CaCO_(3),nano-TiO_(2),and carbon nanotubes are investigated to determine their abilities to reduce the nucleation barrier by providing nucleation sites for hydration products,thereby accelerating cement hydration.Among them,the nano C-S-H seeds are found to be a good nucleation substrate for C-S-H gel,and provided the most significant cement-hydration acceleration.Thus,nano C-S-H seeds are attracting increasing attention from both academia and industry.To date,methods of synthesizing nano C-S-H seeds,as well as the seed nucleation process and mechanism of cement hydration,have all been studied.In many studies,the nano C-S-H suspension is prepared by co-precipitating in the presence of polymer that exhibited nanoscalesized grains and good dispersion stability which followed a non-classical nucleation mode.After applying it to cement,nano C-S-H seeds,with a high surface area,acted as additional nucleation sites for C-S-H gel,which reduced the nucleation barrier of the C-S-H gel.Thus,the nano C-S-H seeds effectively accelerated the cement hydration rate.The nano C-S-H seeds also enhanced the early strength development of the cement,particularly within the first day of aging.In contrast to traditional cement accelerators,nano C-S-H seeds have the advantages of low dosing requirements,good effect on early strength,and no impact on cement and concrete durability.To a certain extent,these seeds also compensate for the slow early-strength growth of supplementary cementitious materials(SCMs).Therefore,nano C-S-H seeds have promising applications in lowtemperature and slipform construction,the production of precast-concrete products,and other projects that require high levels of early strength.Nano C-S-H seeds have the potential to become a widely used hydration accelerator for cement and concrete.In this review,many studies about nano C-S-H seeds are ana

关 键 词：纳米水化硅酸钙 晶种 成核方式 水化 早期强度 

分 类 号：TU528[建筑科学—建筑技术科学]