Environment·Health·Safety

Study on formulation calculation of phosphogypsum-based composite cementitious materials based on expansion and failure of critical AFt

  • Shihao Zhao ,
  • Xihua Lin ,
  • Pengfei Ma ,
  • Yijin Yuan ,
  • Yuxin Gao ,
  • Ping Zhang ,
  • Dali Zhou
Expand
  • 1. China West Construction Guizhou Co.,Ltd.,Guiyang 550081,China
    2. China Construction Materials Technology Research Chengdu Co.,Ltd.
    3. College of Materials Science and Engineering, Sichuan University

Received date: 2020-03-19

  Online published: 2020-09-27

Abstract

In order to prepare a composite cementitious material with large amount of phosphogypsum,on the basis of deter-mining the type of main hydration product,by calculating the boundary conditions of the critical ettringite expansion failure,the optimal dosage range of each component was determined and the effect of it on the mechanical properties and dry shrink-age properties of the composite cementitious materials was studied.The formation and development rule of hydration products by XRD and SEM were researched.The results showed that,by theoretical compounding,when the mineral powder dosage was 50%(mass fraction),the maximum phosphorus gypsum dosage was 26.3%(mass fraction) and the minimum clinker dosage was 23.7%.The optimum ratio group was as follows:28 d,mortar compressive strength was 45.2 MPa,the limit expansion ratio was less than 0.04%.The control group was as follows:28 d,compressive strength was 36.4 MPa,the limit expansion ratio was much greater than 0.04%.The characteristic results of XRD and SEM showed that the hydration products of phosphogypsum-based composite cementitious materials were mainly AFt and C-S-H gels,and Ca(OH)2 was almost completely reacted.The amount of ettringite produced in the control group was much larger than that of the optimal ratio group,and there were many cracks in the microstructure.The crack indicated that the theoretical ratio calculation can be effectively used to optimize the compatibility of the phosphogypsum-based composite cementitious material.

Cite this article

Shihao Zhao , Xihua Lin , Pengfei Ma , Yijin Yuan , Yuxin Gao , Ping Zhang , Dali Zhou . Study on formulation calculation of phosphogypsum-based composite cementitious materials based on expansion and failure of critical AFt[J]. Inorganic Chemicals Industry, 2020 , 52(9) : 91 -95 . DOI: 10.11962/1006-4990.2019-0518

References

[1] 周玲, 单建军. 提高矿渣水泥早期强度的研究[J]. 建材技术与应用, 2004(2):3-5.
[2] 孙超. 矿渣—粉煤灰混合胶凝体系研究[D]. 大庆:大庆石油学院, 2006.
[3] 王露, 刘数华. 钙矾石相的研究综述[J]. 混凝土, 2013(8):83-86,90.
[4] 陈胡星, 李东旭, 叶青, 等. 钙矾石与方镁石双膨胀作用研究[J]. 硅酸盐学报, 2000(S1):1-5.
[5] 周剑波. 延迟钙矾石生成影响因素研究[D]. 哈尔滨:哈尔滨工业大学, 2011.
[6] 高育欣, 余保英, 王军, 等. 超硫酸盐水泥的水化产物及孔结构特性[J]. 土木建筑与环境工程, 2014(3):118-122.
[7] 杨凤娟. 部分降解喷施固结复合材料的研究[D]. 郑州:郑州大学, 2009.
[8] 安树好. 高掺量矿渣水泥的研制及其早强激发机理的研究[D]. 唐山:河北理工学院, 2003.
[9] Battagin A F. Influence of degree of hydration of slag on slag ceme-nt [C]∥New Delhi:Proc.of 9th ICCC, 1992.
[10] Lea F M. 水泥和混凝土化学[M].唐明述.3版. 北京: 中国建筑工业出版社, 1984.
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