Effect of BaO on mineral structure and hydration behavior of phosphoaluminate cement
- 23 Downloads
Phosphoaluminate cement (PAC) clinker was one new type of special cement, which exhibits good mechanical properties and durability. In this paper, the effect of BaO on the mineral structure and hydration behavior of PAC clinker were investigated. The experimental results showed that the mineral structure of PAC clinker was modified by the addition of barium oxide (BaO). The optimal content of BaO in PAC clinker was 10.5 mol% (the substitution mole ratio of BaO for CaO, calcium oxide). Compared with reference specimen, the rate of strength growth of hardened paste for PAC clinker with 10.5% BaO cured for 1, 3, 7 and 28 days was 50.8, 21.0, 27.0 and 49.9%, respectively. The possible reason was that the addition of BaO could activate crystal structure of calcium phosphoalumniate (8CaO·6Al2O3·P2O5, C8A6P, C8A6P) and improve its hydration activity, which has been proven by the XRD and hydration heat analysis. The addition of BaO also affected the ratio of hydration products of PAC clinker, which were illustrated by XRD and DSC analysis. The MIP analysis showed that the addition of BaO could optimize the pore structure of hardened paste for PAC clinker, which was accordance with the discussion of compressive strength of hardened paste for PAC clinker. In conclusion, the addition of BaO dramatically improved the compressive strength of hardened paste for PAC clinker and changed remarkably its ratio of hydration products.
KeywordsBarium oxide Phosphoaluminate Hydration Compressive strength
This work is supported by the 13th Five-Year the State Key Development Program (2016YFB0303505), Natural Science Foundations of China (51672108), Key Research and Development Plan of Shandong Province (2018GGX107009), Postdoctor Program of China (2018M633742) and University of Jinan (XBH1718). Also, supports from the 111 Project of International Corporation on Advanced Cement-based Materials (No. D17001) are greatly appreciated.
- 5.Rasheeduzzafar, Dakhil FH, Al-Gahtani AS, Al-Saadoun SS, Bader MA. Influence of cement composition on the corrosion of reinforcement and sulfate resistance of concrete. ACI Mater J. 1990;87(2):114–22.Google Scholar
- 6.Janevic T, Petrovic O, Bjelic I, Kubera A. Numerical simulation of sulfate ion migration in cement concrete under corrosion fatigue. Int J Pavement Res Technol. 2012;5(19):169–75.Google Scholar
- 10.Tang XJ, Ling-Chao LU. Review on the hydration and hardening of alite-sulphoaluminate cement. J Univ Jinan. 2006;20:202.Google Scholar
- 11.Zhang WW, Lu LC, Cui YJ, Chang J, Cheng X. Microstructure and properties of belite-calcium barium sulphoaluminate. J Chin Ceram Soc. 2007;35:467–71.Google Scholar
- 13.Wang S, Chen C, Lu L, Cheng X. Effects of slag and limestone powder on the hydration and hardening process of alite-barium calcium sulphoaluminate cement. Constr Build Mater. 2012;35(35):227–31.Google Scholar
- 14.Lingchao Z, Shiquan S. Durability of alite-calcium barium sulphoaluminate cement. J Wuhan Univ Technol-Mater Sci. 2009;24(6):98.Google Scholar
- 18.Shiqun L, Guohui Z, Ning Z. Study on hydraulic activity of aluminum-rich area in CaO-Al2O3-P2O5 system. J Chin Ceram Soc. 1998;26(2):142–8.Google Scholar
- 23.National standard of the people’s republic of China. GBT 1345-2005. Standard for test method of fineness of cement. Beijing: China Standard Press.Google Scholar
- 24.National standard of the people’s republic of China. GB/T50082-2009. Standard for test method of mechanical properties on ordinary concrete. Beijing: China Architecture & Building Press.Google Scholar
- 25.Yang S, Wang S, Lu L, et al. Constituent phases and mechanical properties of iron oxide-additioned phosphoaluminate cement. Mater de Constr. 2015;65(318):052.Google Scholar
- 26.Zhongwei W. An approach to the recent trends of concrete science and technology. J Chin Ceram Soc. 1979;7:262.Google Scholar