High-Volume Mineral Admixtures Cement: The Effects of Particle Size Distribution

Abstract

The effects of high-volume slag-fly ash cement with different particle sizes on hydration degree, microstructure and mechanical properties were systematically studied, by means of laser particle size (DLS), X-ray diffraction (XRD), comprehensive thermal analysis (TG-DTA), scanning electron microscopy (SEM) and mechanical properties tests. The results show that suitable particle size distribution of cementitious material has significantly promoting effects on hydration reaction rate and mechanical properties. Compared with slag without further grinding, the slag after ball milling for 4 h has an obvious improvement in reactivity, which also provides a faster hydration rate and higher compressive strength for the cementitious material. When the slag milled for 1 and 4 h is mixed at a mass ratio of 2:1 (i e, slag with D ₅₀ of 7.4 µm and average size of 9.9 µm, and slag with D ₅₀ value of 2.6 µm and average size of 5.3 µm), and a certain amount of fly ash is added in, the most obvious improvement of compressive strength of cement is achieved.

Keywords

ultrafine slag / microstructure / compressive strength / particle size

References

[1] Zhongwei W, Huizhen L. High Performance Concrete[M], 1999 Beijing: China Railway Press.

[2] Newman J, Choo B S. Advanced Concrete Technology[M], 2003 Oxford: Elsevier.

[3] Aïtcin P C. High-Performance Concrete[M], 2004 London: Taylor and Francis.

[4] Juenger M C G, Winnefeld F, Provis J L, et al. Advances in Alternative Cementitious Binders[J]. Cement and Concrete Research, 2010, 41(12): 1 232-1 243.

[5] Rafat S. Use of Municipal Solid Waste Ash in Concrete[J]. Resources, Conservation and Recycling, 2010, 55(2): 83-91.

[6] Rakesh K, Sanjay K, Mehrotra S P. Towards Sustainable Solutions for Fly Ash through Mechanical Activation[J]. Resources, Conservation and Recycling, 2007, 52(2): 157-179.

[7] Zheng Qing, Xu Xiaodong, Du Ze, et al. Effect of Mineral Powder Content on Concrete Performance[J] Concrete and Cement Products, 2011 (04): 22–24

[8] Li Q. Study on the Effect of Large Amount of High-Performance Slag Powder on the Properties of Cement-Based Materials[D], 2015 Wuhan: Wuhan University of Technology.

[9] Zhang B, Tan H, Shen W, et al. Nano-Silica and Silica Fume Modified Cement Mortar Used as Surface Protection Material to Enhance the Impermeability[J]. Cement and Concrete Composites, 2018, 92: 7-17.

[10] Zhang T. Optimal Matching of Cement Clinker and Auxiliary Cementitious Materials[D], 2012 Changsha: South China University of Technology.

[11] Zhou X. Effect of Particle Size Distribution of Auxiliary Cementitious Materials on Cement Properties[D], 2017 Mianyang: Southwest University of Science and Technology.

[12] Bensted J. Hydration of Portland Cement[J]. Advances in Cement Technology, 1983: 307–347

[13] He Z, Hu L. Hydration Mechanism of Cement-Based Materials with Different Si-rich Mineral Admixtures[J]. Journal of Wuhan University of Technology-Materials Science Edition, 2018, 33(3): 654-660.

[14] Shi C. Alkali-Activated Cements and Concretes[M], 2003 Beijing: Chemical Industry Press.