Continuous monitoring for leaching of calcium sulfoaluminate cement pastes incorporated with ZnCl 2 under the attacks of chloride and sulfate
Journal article, 2019

Ionic zinc is considered as an environmental pollutant. This work systematically investigated leaching mechanisms of calcium sulfoaluminate cement (CSA) pastes incorporated with/without ZnCl 2 under the attacks of chloride and/or sulfate. The leaching behaviors of CSA pastes in the leaching solution are in-situ and continuously monitored by innovative non-contact electrical impedance measurement (NCEIM) and pH meter. The dissolution and diffusion during the leaching process are experimentally identified. Other techniques are also performed to verify the finding of NCEIM: the ion chromatograph and inductively coupled plasma optical emission spectrometer reveal the leaching or decomposition sequence of CSA pastes during the leaching process. Besides, results from XRD and SEM techniques demonstrate that main solid products in CSA pastes are ettringite and calcium monosulfoaluminate hydrates. The incorporation of Zn in the pastes has great impact on the decomposition of CSA pastes in the temperature elevation. External chloride and/or sulfate attacks significantly alter the pore structure of CSA pastes during the leaching process.

Calcium sulfoaluminate cement

Electrical impedance

Sulfate

Chloride

Zinc

Leaching

Author

Shengwen Tang

Wuhan University

Junhui Yuan

Wuhan University

Rongjin Cai

Wuhan University

Xuanchun Wei

Wuhan University

Cheng Zhao

Wuhan University

Xinhua Cai

Wuhan University

Zhen He

Wuhan University

Teresa E Chen

Hong Kong University of Science and Technology

Chalmers, Architecture and Civil Engineering, Structural Engineering

Chemosphere

0045-6535 (ISSN) 18791298 (eISSN)

Vol. 223 91-98

Subject Categories

Ceramics

Construction Management

Materials Chemistry

DOI

10.1016/j.chemosphere.2019.02.047

PubMed

30771652

More information

Latest update

4/5/2022 6