Microstructural changes in alkali-activated slag mortars induced by accelerated carbonation

Ning Li; Nima Farzadnia; Caijun Shi

doi:10.1016/J.CEMCONRES.2017.07.008

Microstructural changes in alkali-activated slag mortars induced by accelerated carbonation

Ning Li, Nima Farzadnia, Caijun Shi

Civil Engineering and Management

Research output: Contribution to journal › Article › peer-review

Abstract

This study investigated microstructural changes in alkali-activated slag (AAS) mortars after carbonation using XRD, FTIR, DTG, 1H NMR and SEM examinations. The results showed that decalcification of C-S-H was the main reaction in carbonation of AAS. The C-S-H with a low Ca/Si was more vulnerable to decalcification in AAS samples activated by waterglass. Besides, AAS mortars demonstrated a lower CaCO₃ formation compared to Portland cement mortars. Calcite and vaterite were the major CaCO3 polymorphs produced by carbonation of AAS precipitated mainly in gel pores and spaces in C-S-H interlayers. Meanwhile, the carbonation also caused a certain volume of contraction in AAS mortars.

Original language	English
Pages (from-to)	214-226
Number of pages	13
Journal	Cement and Concrete Research
Volume	100
Early online date	28 Jul 2017
DOIs	https://doi.org/10.1016/J.CEMCONRES.2017.07.008
Publication status	Published - Oct 2017

Keywords

alkali-activated slag
carbonation
microstructure
C-S-H

Access to Document

10.1016/J.CEMCONRES.2017.07.008

Cite this

@article{58b515c1a49c4dfb9ebbbe1053f1b99a,

title = "Microstructural changes in alkali-activated slag mortars induced by accelerated carbonation",

abstract = "This study investigated microstructural changes in alkali-activated slag (AAS) mortars after carbonation using XRD, FTIR, DTG, 1H NMR and SEM examinations. The results showed that decalcification of C-S-H was the main reaction in carbonation of AAS. The C-S-H with a low Ca/Si was more vulnerable to decalcification in AAS samples activated by waterglass. Besides, AAS mortars demonstrated a lower CaCO3 formation compared to Portland cement mortars. Calcite and vaterite were the major CaCO3 polymorphs produced by carbonation of AAS precipitated mainly in gel pores and spaces in C-S-H interlayers. Meanwhile, the carbonation also caused a certain volume of contraction in AAS mortars.",

keywords = "alkali-activated slag, carbonation, microstructure, C-S-H",

author = "Ning Li and Nima Farzadnia and Caijun Shi",

year = "2017",

month = oct,

doi = "10.1016/J.CEMCONRES.2017.07.008",

language = "English",

volume = "100",

pages = "214--226",

journal = "Cement and Concrete Research",

issn = "0008-8846",

publisher = "Elsevier BV",

}

TY - JOUR

T1 - Microstructural changes in alkali-activated slag mortars induced by accelerated carbonation

AU - Li, Ning

AU - Farzadnia, Nima

AU - Shi, Caijun

PY - 2017/10

Y1 - 2017/10

N2 - This study investigated microstructural changes in alkali-activated slag (AAS) mortars after carbonation using XRD, FTIR, DTG, 1H NMR and SEM examinations. The results showed that decalcification of C-S-H was the main reaction in carbonation of AAS. The C-S-H with a low Ca/Si was more vulnerable to decalcification in AAS samples activated by waterglass. Besides, AAS mortars demonstrated a lower CaCO3 formation compared to Portland cement mortars. Calcite and vaterite were the major CaCO3 polymorphs produced by carbonation of AAS precipitated mainly in gel pores and spaces in C-S-H interlayers. Meanwhile, the carbonation also caused a certain volume of contraction in AAS mortars.

AB - This study investigated microstructural changes in alkali-activated slag (AAS) mortars after carbonation using XRD, FTIR, DTG, 1H NMR and SEM examinations. The results showed that decalcification of C-S-H was the main reaction in carbonation of AAS. The C-S-H with a low Ca/Si was more vulnerable to decalcification in AAS samples activated by waterglass. Besides, AAS mortars demonstrated a lower CaCO3 formation compared to Portland cement mortars. Calcite and vaterite were the major CaCO3 polymorphs produced by carbonation of AAS precipitated mainly in gel pores and spaces in C-S-H interlayers. Meanwhile, the carbonation also caused a certain volume of contraction in AAS mortars.

KW - alkali-activated slag

KW - carbonation

KW - microstructure

KW - C-S-H

UR - https://www.webofscience.com/wos/woscc/full-record/WOS:000411547800020?SID=EUW1ED0B50XH83gwxLA1SxgaYeJvh

U2 - 10.1016/J.CEMCONRES.2017.07.008

DO - 10.1016/J.CEMCONRES.2017.07.008

M3 - Article

SN - 0008-8846

VL - 100

SP - 214

EP - 226

JO - Cement and Concrete Research

JF - Cement and Concrete Research

ER -

Microstructural changes in alkali-activated slag mortars induced by accelerated carbonation

Abstract

Keywords

Access to Document

Other files and links

Fingerprint

Cite this