Influence of Additve on Over-Sulfur Phosphogypsum-Ground Granulate Blast-Furnace Slag Cement

Abstract:

The effect of sodium hydroxide (NaOH) and polycarboxylate superplasticizer amount on over-sulfur phosphogypsum–ground granulate blast-furnace slag cement was investigated. The mechanical performances and hydration mechanism of the cement with different proportions of NaOH and polycarboxylate superplasticizer (BASF) were analyzed based on setting time, the additive quantity of water, strength test, XRD and SEM analyses. The results showed that the polycarboxylate superplasticizer, can increase the densification and the strength of the cement ,to improve the performance of the cement anti-carbonation properties. NaOH as an alkali activator significantly reduces the cement setting time and improves the cement early strength. But the acceleration of hydration process produces coarse crystalline hydration products and the osteoporosis structure of hardened paste, which has a negative effect on long term strength.

• Periodical: Applied Mechanics and Materials (Volumes 744-746)
• Pages: 1431-1434
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.744-746.1431
• Online since: March 2015
• Authors: Zhi Jiang Lv*, Zong Shou Lin, Ya Han, Hao Jie Wang
• Keywords: Phosphogypsum, Polycarboxylate Superplasticizer, Sodium Hydroxide

References

[1] M. Azouazi, Y. Ouahidi, et al. Natural radioact ivity in phosphates, phosphogypsum and natural waters in Morocco[J]. Journal of Environmental Radioactivity 2001, 54, 231–242.

DOI: 10.1016/s0265-931x(00)00153-3

[2] P.M. Rutherford, M.J. Dudas, J.M. Arocenab. Heterogeneous distribution of radionuclides, barium andbstrontium in phosphogypsum by-product[J]. The Science of the Total Environment, 1996, 180, 201-209.

DOI: 10.1016/0048-9697(95)04939-8

[3] P.P. Haridasan, C.G. Maniyan, et al. Dissolution characteristics of 226Ra from phosphogypsum [J]. Journal of Environmental Radioactivity, 2002, 62 287–294.

DOI: 10.1016/s0265-931x(02)00011-5

[4] Mun KJ, Hyoung WK, Lee CW, So SY, et al. Basic Properties Non-sintering Cement Using Phosphogypsum and Waste Lime as Activator[J]. Construction and Building Materials, 2007, 21(6): 1342-1350.

DOI: 10.1016/j.conbuildmat.2005.12.022

[5] Weiguo Shen, Mingkai Zhou, Qinglin Zhao. Study on Lime–Fly Ash–Phosphogypsum Binder[J]. Construction and Building Materials, 2007, 21(7): 1480-1485.

DOI: 10.1016/j.conbuildmat.2006.07.010

[6] Guo Xiao Lu, Shi Hui Sheng. Thermal Treatment and Utilization of Flue Gas Desulphurization Gypsum as an Admixture in Cement and Concrete[J]. Construction and Building Materials, 2008, 22(7): 1471-1476.

DOI: 10.1016/j.conbuildmat.2007.04.001