Carbonation Characteristics of Alkali Activated Blast-Furnace Slag Mortar

Song, Keum-Il; Yang, Keun–Hyeok; Lee, Bang Yeon; Song, Jin‐Kyu

doi:10.4334/jkci.2012.24.3.315

Cited by 11 publications

(7 citation statements)

References 7 publications

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Section: Represents Strengthssupporting

confidence: 82%

“…Similar observation was also made by Song et al [69] for AAS binder. The authors [69] reported that the major hydration products of AAS were C-S-H, with almost no portlandite, unlike the products of OPC. After carbonation, the C-S-H of AAS turned into an amorphous silica gel which was most likely to account for the fact that the compressive strength of AAS became weaker after carbonation.…”

Section: Represents Strengthssupporting

confidence: 82%

See 1 more Smart Citation

Durability of mortar and concrete containing alkali-activated binder with pozzolans: A review

Hossain

Karim

Hossain

et al. 2015

Construction and Building Materials

135

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Section: Represents Strengthssupporting

confidence: 82%

Section: Represents Strengthssupporting

confidence: 82%

Durability of mortar and concrete containing alkali-activated binder with pozzolans: A review

Hossain

Karim

Hossain

et al. 2015

Construction and Building Materials

135

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“…For rate of carbonation (X > 0.6 %), all the XRD peaks in the diffraction pattern are decreasing due to the increase in the amorphous structure of the silica gel [23][24][25]. This is supported by the obtained result for the CO 3 --(1420-1590 cm −1 ) group in the FTIR analysis besides the reduction in the bound water.…”

Section: The Xrd Quantitative Analysis For the Microstructure Study Due To Calcination And Carbonation Processesmentioning

confidence: 76%

“…On the other hand, it increases for (X > 0.6 %) due to the increase in the relative proportion of the capillary porosity, which leads in turn to an increase in the ionic diffusivity of the carbonation reaction in OPC matrix [24]. The stretching mode S-O (1100-1200 cm −1 ) (ν 3 SO 4 -) shows similar behavior to that of the previous mode (1420-1590 cm −1 ) and that is mainly related to the ettringite and gypsum formation due to the effect of the reaction of the liberated Ca ++ ions with the SO 4 -and CO 3 -groups [25]. The out-of-plane bending mode of vibration of CO 3 --(842-910 cm −1 ) has the same trend as the aforementioned modes of vibrations and has a minimum value at (X = 0.6%) and that is attributed to the formation of CaCO 3 (calcite).…”

Section: Ftir Spectramentioning

confidence: 89%

Calcination process and kinetic carbonation effect on the hydrated and anhydrate phases of the OPC matrix at early age of hydration

2021

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This study aims to improve the understanding of the effect of both calcination temperature and the carbonation process on cement pastes by analyzing the Fourier-transform infrared spectroscopy (FTIR) principal vibration modes. In this regard, six samples of cement pastes, identified as (CS1, CS2, CS3, CS4, CS5 and CS6), mixed with white sugar with different concentrations (X = 0, 0.2, 0.4, 0.6, 0.8, and 1.1 %), respectively, were prepared. These blended cement samples were heated (calcined) at a temperature of about 600°C. Moreover, an additional sugar-free sample tagged as CS0 was prepared and cured at room temperature for 7 days. Afterward, these samples were subjected to FTIR spectroscopy and X-ray diffraction to investigate the effect of the calcination and the carbonation process on the principal mode of vibrations and the microstructure of the ordinary Portland cement (OPC) matrix as well. The characteristics of the FTIR principal modes of vibrations were investigated. Besides, the relaxation time and the rotational energy barrier were calculated for different sugar concentrations. This study revealed that the kinetic reaction of the carbon contained in the different samples with the C 3 S, C 2 S, C-S-H and CH phases leads to the formation of calcium carbonate CaCO 3 , where the rate of formation depends upon the carbonation rate of samples. The critical variation for the relaxation time and rotational energy barrier clearly appeared at X = 0.6%. Moreover, the kinetic carbonation of both clinker phases and the hydrated phases in the OPC matrix system mainly depends upon the rate of the polymerization of the silicate group inside the matrix of OPC.

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“…In the experiment by CO 2 concentration, he describes the inconsistency between the mechanism of carbonation in the laboratory’s high CO 2 environment and in the real environment. In such high concentration CO 2 conditions, in the case of carbonation of BFS-based AACs, carbonation may reduce the compressive strength depending on the reaction conditions [ 22 , 24 , 25 , 26 ]. F. Puertas et al [ 22 ] showed that when using sodium hydroxide as the alkali activator, the compressive strength increased by carbonation; however, when using sodium silicate, the compressive strength decreased by carbonation.…”

Section: Introductionmentioning

confidence: 99%

Physical and Chemical Relationships in Accelerated Carbonation Conditions of Alkali-Activated Cement Based on Type of Binder and Alkali Activator

Yamazaki

Kim

Kadoya³

et al. 2021

Polymers

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Alkali-activated cements prepared from aluminosilicate powders, such as blast furnace slag and fly ash, are rapidly attracting attention as alternatives to cement because they can significantly reduce CO2 emissions compared to conventional cement concrete. In this study, we investigated the relationship between the physical and chemical changes by accelerated carbonation conditions of alkali-activated cements. Alkali-activated cements were prepared from binders composed of blast furnace slag and fly ash as well as alkali activators sodium silicate and sodium hydroxide. Physical changes were analyzed from compressive strength, pH, and neutralization depth, and chemical changes were analyzed from XRD, TG-DTG, and 29Si MAS NMR. The C–(N)–A–S–H structure is noted to change via carbonation, and the compressive strength is observed to decrease. However, in the case of Na-rich specimens, the compressive strength does not decrease by accelerated carbonation. This work is expected to contribute to the field of alkali-activated cements in the future.

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Carbonation Characteristics of Alkali Activated Blast-Furnace Slag Mortar

Cited by 11 publications

References 7 publications

Durability of mortar and concrete containing alkali-activated binder with pozzolans: A review

Durability of mortar and concrete containing alkali-activated binder with pozzolans: A review

Calcination process and kinetic carbonation effect on the hydrated and anhydrate phases of the OPC matrix at early age of hydration

Physical and Chemical Relationships in Accelerated Carbonation Conditions of Alkali-Activated Cement Based on Type of Binder and Alkali Activator

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