Journal of South China University of Technology (Natural Science Edition) ›› 2010, Vol. 38 ›› Issue (9): 80-84.doi: 10.3969/j.issn.1000-565X.2010.09.015

• Materials Science & Technology • Previous Articles     Next Articles

Influences of S/Al of Cement and Sulfate in Extravasation Solution on Chloride Threshold Value

Li Peng-ping1  Su Da-gen1  Wang Sheng-nian2  Fan Zhi-hong 1.2   

  1. 1.Key Laboratory of Specially Functional Materials of the Ministry of Education,South China University of Technology,Guangzhou 510640,Guangdong,China;2.Key Laboratory of Harbor ＆ Marine Structure Durability Technology of the Ministry of Communications,Guangzhou 510230,Guangdong,China
  • Received:2010-03-24 Revised:2010-04-09 Online:2010-09-25 Published:2010-09-25
  • Contact: 苏达根（1948-），男，教授，博士生导师，主要从事土木工程材料和生态环境材料研究．E-mail：dgsu@scut．edu．cn E-mail:lpp232@yahoo．com．cn
  • About author:黎鹏平（1980-），男，博士，主要从事海工混凝土耐久性研究．
  • Supported by:

    广东省科技攻关项目（2008B080501036）; 交通部西部交通建设科技项目（200632800003）

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Abstract:

This paper deals with the influences of the S/Al molar ratio of cement and the sulfate in extravagation solution on the chloride threshold value via the linear polarization method,the mercury injection test and XRD.The results show that,with the increase of S/Al molar ratio,the chloride threshold value first increases and then decreases,while the chloride bounded in cement hydration products keeps reducing,that the S/Al molar ratio corresponding to the maximum chloride threshold value decreases with the increase of Al2O3 content of cement.More-over,it is also found that,when the specimens are immersed in the composite solution with the SO42- and Cl-concentrations similar to those of seawater,the chloride threshold value first increases and then decreases with the increase of S/Al molar ratio,but it is lower than that of the specimens immersed in NaCl solution,and that,with the penetration of the mortar first becomes denser and then presents a volume expansion due to an excessive penetration,thus resulting in the decrease in chloride threshold value.

Key words: sulfate, SO3/Al2O3 molar ratio, extravasated chloride, chloride threshold value, pore structure