Alkali Activation of Granulated Blast Furnace Slag

Abstract:

In order to stimulate the potential cementitious property of granulated blast furnace slag (GBFS), the ground GBFS sample (Wei Fang Iron and Steel Corporation, China) was activated by lime and gypsum under different dosages. The results showed that lime is an effective activator for the slag, and the optimum dosage of lime is about 10% (w/w) of the slag. At the optimum dosage of lime, the 28 days compressive strength of the lime-slag paste is higher than that of 32.5 ordinary Portland cement (OPC). But, the early age strength (3 and 7 days compressive strength) of the lime-slag paste is lower than that of the OPC. Addition of gypsum can effectively improve the early age strength of the lime-slag paste. At the ratio of gypsum:lime:slag of 8.2:9.2:82.6 (w/w), both the early and long-term compressive strengths of the gypsum-lime-slag paste are higher than that of the OPC. According to XRD, TG-DTA and SEM detections of the hydration products of the lime-slag paste, the gypsum-lime-slag paste and the OPC paste, it reveals that the hydration process of the GBFS-based cementitious material is different from the ordinary Portland cement and the presence of ettringite (AFt) contributes to the early age strength of the pastes. The major hydration product of the OPC paste (<7 days) were measured as ettringite (AFt), but the AFt phase was not detected in the hydration product of the lime-slag paste and the major hydration product of the lime-slag paste was determined as amorphous CSH gel. However, AFt was detected in the hydration products of the gypsum-lime-slag paste in the early stages of hydration, and the formation of AFt is favorable for the early strength improvement of the material.

• Periodical: Advanced Materials Research (Volume 158)
• Pages: 1-11
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.158.1
• Online since: November 2010
• Authors: Zi Qiao Jin, Xian Jun Lu, Shu Gang Hu
• Keywords: Alkali-Activation, Cementing Property, Granulated Blast-Furnace Slag

References

[1] Cahit bilim, Cengiz D. Atis, and Harun Tanyildizi: Advances in Engineering Software 40(2009), p: 334.

[2] Tatiana Bakharev, Jay Gnananandan Sanjayan, Yi-Bing Cheng: Cement and Concrete Research, 1999, 29: 113-120.

[3] Sylvain Murgier, Helene Zanni, Daniel Gouvenot: C. R. Chimie, 2004, 7: 389-394.

[4] Wu Dahua, Wu Yongge, and Lin rong: Petroleum Drilling Techniques. Vol. 25, (1997), p.31.

[5] Sanjay Kumar, Rakesh Kumar, and A. Bandopadhyay: Cement & Concrete Composites 30 (2008), p.679.

[6] A. Fernandez-Jimenez, J. G. Palomo, F. Puertas: ACement and Concrete Research, 29(1999): pp.1313-1321.

[7] F. G. Collins, J. G. Sanjayan: Cement and Concrete Research, 29(1999): pp.455-458.

[8] M. Oner: Cement and Concrete Research, 30(2000): pp.473-480.

[9] Gao Shujun, Wu Qisheng, and Zhang Shaoming: Journal of Nan Jing University of technology Vol. 24, (2002), p.25.

[10] Zhu Shoudong, Cui Chong, Xie Yongbo: Property and Application. 28(2000), p.18.

[11] Li Liangyuan, Shi Zongli, Ai Yongping: Journal of the Chinese Ceramic Society. Vol. 36(2008): p.410.

[12] Gao Huijie, Hou Jirui, Yue Xiang'an: Oilfield Chemistry. Vol. 22(2005): p.114.