Bioinspired and biomineralized magnesium oxychloride cement with enhanced compressive strength and water resistance

Qianqian Ye; Yufei Han; Shifeng Zhang; Qiang Gao; Wei Zhang; Hui Chen; Shanshan Gong; Sheldon Q Shi; Changlei Xia; Jianzhang Li

doi:10.1016/j.jhazmat.2019.121099

Bioinspired and biomineralized magnesium oxychloride cement with enhanced compressive strength and water resistance

J Hazard Mater. 2020 Feb 5:383:121099. doi: 10.1016/j.jhazmat.2019.121099. Epub 2019 Aug 25.

Authors

Affiliations

¹ Key Laboratory of Wood Materials Science and Utilization (Beijing Forestry University), Ministry of Education, Beijing 100083, China; Beijing Key Laboratory of Wood Science and Engineering, Beijing Forestry University, Beijing 100083, China; College of Materials Science and Technology, Beijing Forestry University, Beijing 100083, China.
² Department of Mechanical and Energy Engineering, University of North Texas, Denton, TX, 76203, USA.
³ Department of Mechanical and Energy Engineering, University of North Texas, Denton, TX, 76203, USA; College of Materials Science and Engineering, Nanjing Forestry University, Nanjing 210037, China.
⁴ Key Laboratory of Wood Materials Science and Utilization (Beijing Forestry University), Ministry of Education, Beijing 100083, China; Beijing Key Laboratory of Wood Science and Engineering, Beijing Forestry University, Beijing 100083, China; College of Materials Science and Technology, Beijing Forestry University, Beijing 100083, China. Electronic address: lijzh@bjfu.edu.cn.

PMID: 31518808
DOI: 10.1016/j.jhazmat.2019.121099

Abstract

High CO₂ emissions during the production process of ordinary Portland cement (OPC) promoted greener-cement development, wherein the application of magnesium oxychloride cement (MOC) can add value to waste in potash industry and reduce environmental hazards. However, its application was restricted by its inferior water resistance. It's a challenge to remarkably increase both the compressive strength and water resistance of MOC. Herein, we demonstrate that cornstarch/sodium polyacrylate (PAAS) MOC composites exhibit increased compressive strength and water resistance. Moreover, the biomineralization process encourages the growth and alignment of phase 5 crystals by a cornstarch template with hydroxyl groups, thus enhancing the compressive strength of MOC. The chelation of magnesium ions and the transformation of phase 5 crystal structure by PAAS can significantly enhance the water resistance of MOC. This composite exhibits a 21.0% increase in compressive strength, and the softening coefficient is also increased from 0.48 to 0.81 in comparison with unmodified-MOC. Meanwhile, the hydrogen bonds between cornstarch and elemental Cl obviously decrease the efflorescence phenomena of the MOC. This MOC composite with a markedly increased compressive strength and water resistance, which was prepared by a facile and green method, may have potential applications in building development and the replacement of OPC.

Keywords: Efflorescence; Hazardous waste utilization; Magnesium oxychloride; Sustainable building; Water resistance.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Compressive Strength*
Construction Materials*
Magnesium Chloride / chemistry*
Materials Testing*
Microscopy, Electron, Scanning
Water / chemistry*

Substances

Magnesium Chloride
Water