Use of bacterial cell walls to improve the mechanical performance of concrete

详细信息    查看全文

• 作者：Ruoting Pei^a ; ^{ruoting.pei@utsa.edu} ; Jun Liu^a ; Shuangshuang Wang^a ; Mijia Yang^b
• 关键词：Concrete ; Carbonation ; Bacterial cell wall ; Bacillus subtilis
• 刊名：Cement and Concrete Composites
• 出版年：2013
• 出版时间：May, 2013
• 年：2013
• 卷：39
• 期：Complete
• 页码：122-130
• 全文大小：1256 K

文摘

This research presents the role of bacterial cell walls of Bacillus subtilis as a concrete admixture to improve the mechanical performance of concrete. The bacterial cell walls are known to mediate microbially induced carbonate precipitation, a process in which CaCO₃ is formed from Ca²⁺ ions and dissolved CO₂. Consistent with such knowledge, incorporation of bacterial cell walls increased carbonation of Ca(OH)₂ and formation of CaCO₃ in concrete. Furthermore, the bacterial cell walls significantly increased compressive strengths of concrete by 15 % while also decreased porosity at 28 days of curing. Assay for CaCO₃ precipitation in vitro indicated that bacterial cell walls, but not dead cells, accelerated carbonation of Ca²⁺ ions in Ca(OH)₂ solution. Since CaCO₃ formed can fill up the void, decrease the porosity and increase the compressive strength in concrete, bacterial cell walls could act as a promising concrete admixture with benefits in enhancing mechanical performance and improving other carbonation-related properties.