华南理工大学学报(自然科学版) ›› 2023, Vol. 51 ›› Issue (1): 76-83.doi: 10.12141/j.issn.1000-565X.220176

所属专题: 2023年材料科学与技术

• 材料科学与技术 • 上一篇    下一篇

不同侧链密度PCE制备的C-S-H/PCE结构及其对水泥早期水化的影响

殷素红 杨幸霖 冯献 曹文湘   

  1. 华南理工大学 材料科学与工程学院,广东 广州 510640
  • 收稿日期:2022-04-06 出版日期:2023-01-25 发布日期:2023-01-02
  • 通信作者: 殷素红(1971-),女,博士,教授,主要从事水泥混凝土材料、绿色低碳建筑材料、碱激发胶凝材料、固体废弃物建材资源化利用等的研究。 E-mail:imshyin@scut.edu.cn
  • 作者简介:殷素红(1971-),女,博士,教授,主要从事水泥混凝土材料、绿色低碳建筑材料、碱激发胶凝材料、固体废弃物建材资源化利用等的研究。
  • 基金资助:
    广东省科技计划项目(2017B020238004);广东省住房与城乡建设厅2021年科技创新计划项目(2021-K20-512247)

Structure of C-S-H/PCE Prepared from PCE with Different Side Chain Densities and Its Effects on Early Hydration Properties of Cement

YIN Suhong YANG Xinglin FENG Xian CAO Wenxiang   

  1. School of Materials Science and Engineering,South China University of Technology,Guangzhou 510640,Guangdong,China
  • Received:2022-04-06 Online:2023-01-25 Published:2023-01-02
  • Contact: 殷素红(1971-),女,博士,教授,主要从事水泥混凝土材料、绿色低碳建筑材料、碱激发胶凝材料、固体废弃物建材资源化利用等的研究。 E-mail:imshyin@scut.edu.cn
  • About author:殷素红(1971-),女,博士,教授,主要从事水泥混凝土材料、绿色低碳建筑材料、碱激发胶凝材料、固体废弃物建材资源化利用等的研究。
  • Supported by:
    the Science and Technology Planning Project of Guangdong Province(2017B020238004)

摘要:

装配式建筑的发展使得在预制件生产中使用早强剂的需求越发强烈,人工合成水化硅酸钙(C-S-H)作为一种新型晶种早强剂,能够显著提高水泥基材料的早期强度,但其较差的分散性限制了其应用。文中以不同侧链密度聚羧酸减水剂(PCE)作为分散剂,通过共沉淀法合成了一系列C-S-H/PCE晶种早强剂,利用X射线衍射分析仪(XRD)、傅里叶红外光谱(FT-IR)、纳米粒度仪(DLS)等探究其对C-S-H晶种结构的影响,并深入研究了C-S-H/PCE晶种早强剂对水泥水化行为、硬化体强度和组成结构的影响。结果表明:PCE的侧链密度越小,C-S-H晶种分散得越好,粒径越小,中位粒径可达339.5 nm,晶种颗粒数量增多,可提供更多的成核位点;掺入C-S-H/PCE能显著加速水泥水化,使水化加速期放热峰提前1.3 h,8 h放热量增加10.8%;掺入C-S-H/PCE后,水泥净浆8 h和1 d龄期硬化体的孔隙率降低,抗压强度分别提高13%和15%。

关键词: 人工合成水化硅酸钙, 聚羧酸减水剂, 侧链密度, 水泥, 早期水化

Abstract:

The development of prefabricated buildings increases the demand for using early strong agents in the production of prefabrication. As a new type of crystal early strength agent, synthetic calcium silicate hydrate (C-S-H) can significantly enhance the early strength of cement-based materials, but its poor dispersibility limits its application. In this paper, the polycarboxylate superplasticizers (PCE) with different side chain density were used as a dispersant to synthesis a series of C-S-H/PCE by means of co-precipitation method. The influence of C-S-H/PCE on the structure of C-S-H was studied with XRD, FT-IR, DLC. Moreover, its influence on the cement hydration behavior, hardened body strength and composition structure was investigated. The results show that the smaller the side chain density of PCE, the better the dispersion of C-S-H seeds and the smaller the particle size; the median particle size can reach 339.5 nm; the increase of the number of seed particles can provide more nucleation sites. The incorporation of C-S-H/PCE can significantly accelerate cement hydration, advance the exothermic peak of hydration acceleration by 1.3 h, and increase the heat release by 10.8% at 8 h. After the incorporation of C-S-H/PCE, the porosity of the hardenite of the cement slurry decreases at 8 h and 1 d and the compressive strength increases by 13% and 15%, respectively.

Key words: synthetic calcium silicate hydrate, polycarboxylate superplasticizer, side chain density, cement, early hydration

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