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Influence of the concentration of seawater on the early hydration properties of calcium sulphoaluminate (CSA) cement: A preliminary study

journal contribution
posted on 2021-12-17, 04:37 authored by Chuanlin Wang, Zeping Liu, Tengteng Zhang, Yuxuan Zhang, Zehong Liu, Xianbo ZhaoXianbo Zhao
This research investigates the effect of seawater of different concentrations on the hydration process and microstructure of calcium sulphoaluminate (CSA) cement. It studies the CSA cement pastes via experiments carried out to determine the initial and final setting times, mechanical strength and chemical shrinkage with X-ray diffraction (XRD), scanning electron microscopy (SEM) and simultaneous differential thermal-thermogravimetric (DTA-TG) analysis. The DTA-TG and XRD results showed that the main hydration products were ettringite (AFt) and aluminum hydroxide in the CSA cement paste mixed with both freshwater and seawater, while a small amount of ettringite (AFt) became monosulfate (AFm) in the freshwater-mixed CSA cement. The SEM results demonstrate that seawater can improve the microstructure of CSA cement paste in the early stage of hydration (1 d) but impairs the microstructure of the CSA cement matrix in the later stage of hydration (7 d). The experimental results also indicate that a high concentration of seawater can extend the setting time, increase the chemical shrinkage and decrease the mechanical strength of CSA cement.

Funding

Category 2 - Other Public Sector Grants Category

History

Volume

11

Issue

6

Start Page

1

End Page

15

Number of Pages

15

eISSN

2075-5309

ISSN

2075-5309

Publisher

MDPI

Additional Rights

CC BY 4.0

Language

en

Peer Reviewed

  • Yes

Open Access

  • Yes

Acceptance Date

2021-06-04

External Author Affiliations

Shantou University, China

Era Eligible

  • Yes

Journal

Buildings

Article Number

243