Preparation and application of fine-grinded cement in cement-based material
Preparation and application of fine-grinded cement in cement-based material
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DOI：
10.1016/j.conbuildmat.2017.09.023
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发表时间：
2017-12
影响因子：
7.4
通讯作者：
Bingliu Zhang;H. Tan;B. Ma;Fangjie Chen;Zhenghang Lv;L. Xin
中科院分区：
文献类型：
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作者：
Bingliu Zhang;H. Tan;B. Ma;Fangjie Chen;Zhenghang Lv;L. Xin
水泥基材料中掺入高效减水剂可获得较低的水灰比。但也存在另一个问题：水泥矿物的水化程度明显降低。一般来说，粒径越细，水化程度越高，但也会带来水化过程过快的问题，导致对力学性能的贡献很小。此外，储存和运输过程中的稳定性也是一个不容忽视的问题。本研究采用表面改性剂和微磨介质制备了细磨水泥，旨在控制早期水化过程，提高粉磨效率。采用气相色谱法研究了波特兰水泥（PC）浆体或砂浆的水化产物、孔隙率和界面过渡区（ITZ）。结果表明，表面改性剂和MGM的加入可以提高GC的制备效率，控制早期水化过程。用GC部分取代PC，最佳用量为20%，可明显提高胶凝效率，抗压强度明显提高。与PC单一体系相比，GC的加入可以改善水泥的水化程度、孔结构和界面处的微观结构。研究结果可为混凝土搅拌站胶凝材料体系的设计提供指导。
Low water/cement ratio in cement-based materials can be obtained with the incorporation of the superplasticizer. However, another problem can be found: the hydration degree of the cement minerals is obviously reduced. Generally, the hydration degree can be promoted with finer particle size, while this also brings about the problem of too fast hydration process at very early age, resulting in little contribution to the mechanical performance. Additionally, the stability in storage and transportation process is also a concern that cannot be ignored. In this study, the fine-grinded cement (GC) was prepared in the presence of surface modifier and micro-grinding media (MGM), with intention to control the early hydration process and promote the grinding efficiency. The hydration products, porosity and interfacial transition zone (ITZ) of Portland cement (PC) paste or mortar with GC were investigated. The results show that the efficiency of GC preparation can be promoted and the hydration process in the early age can be controlled with the addition of the surface modifier and MGM. Partial replacement of PC by GC, with an optimal dosage of 20% GC, can obviously increase the cementitious efficiency, resulting in an obvious enhancement to the compressive strength. The hydration degree, pore structure and the microstructure in ITZ can be improved in the presence of GC, in comparison with PC single system. Such results can provide guidance on the design of the cementitious component system in concrete mixing plant.