Hardening Performance and Mechanism of Fluosilicate Surface Treatment Agent on Cement-Based Materials

Abstract:

Based on the theory of ecological resources recycling, the effects of matrix quality, surface treatment method, soaking time, age after treatment and fluosilicate cation on hardening cement based materials were investigated by using the byproduct of phosphate fertilizer production namely fluosilicate as the surface treatment agent of cement-based materials and changing different surface treatments. The results showed that the permeation capacity of surface hardener solution , the wear resistance and surface hardness of cement-based materials were significantly improved by the treatments of surface sanding and oven drying. Both surface spraying and submerging methods can promptly increase the hardening effect by more than 20%, manifesting as the rapid improvement of wear resistance in 1 day and the maintenance of that in 7 days. The effective spraying amount and soaking time were 100g/m²-200g/m² and 6 h, respectively. The fluosilicate surface hardener exhibited better hardening effect than the silicate surface hardener for those matrix materials with different quality, especially for the matrix materials with low compactness. The magnesium fluosilicate displayed the best hardening effect. Besides, the mechanism of fluosilicate and silicate surface hardeners were discussed and compared. The results show that the fluosilicate surface hardener produced crystals and colloids by reacting with cement hydrates to fill the void and improve the compactness, other than the silicate surface hardener which produced calcium silicates by reacting with cement hydrates. As a result, the hardness and wear resistance of cement-based materials are improved, but also the probability of a potential alkali-aggregate reaction is substantially reduced.

• Periodical: Materials Science Forum (Volume 898)
• Pages: 1996-2003
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.898.1996
• Online since: June 2017
• Authors: Xiao Liu*, Jia Nan Guan, Yun Sheng Zheng, Zi Ming Wang, He Qing Shen, Xiao Wei Ren
• Keywords: Cement-Based Materials, Fluosilicate, Hardening, Silicate, Surface Treatment

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