X-ray microtomography shows pore structure and tortuosity in alkali-activated binders

Provis, John L.; Myers, Rupert J.; White, Claire E.; Rose, Volker; Deventer, J.S.J. van

doi:10.1016/j.cemconres.2012.03.004

Cited by 447 publications

(199 citation statements)

References 38 publications

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“…This is probably due to the changes in pore size, porosity and tortuosity introduced though the addition of the slag [48]. Increasing the thickness of the GFC specimens can increase the sound absorption in the low frequency region, to a greater extent than would be predicted simply from the fact that there is more material present through which the sound waves must be transmitted, but has insignificant effect at higher frequencies.…”

Section: Acoustic Absorptionmentioning

confidence: 72%

Mechanical, thermal insulation, thermal resistance and acoustic absorption properties of geopolymer foam concrete

Zhang

Provis

Reid³

et al. 2015

Cement and Concrete Composites

Self Cite

466

160

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This study reports the synthesis and characterization of geopolymer foam concrete (GFC). A Class F fly ash with partial slag substitution was used for GFC synthesis by mechanical mixing of preformed foam. The GFCs exhibited 28 day compressive strengths ranging from 3 to 48 MPa with demolded densities from 720 to 1600 kg/m 3 (105°C oven-dried densities from 585 to 1370 kg/m 3 ), with the different densities achieved through alteration of the foam content.The thermal conductivity of GFCs was in the range 0.15 to 0.48 W/m·K, showing better thermal insulation properties than normal Portland cement foam concrete at the same density and/or at the same strength. The GFC derived from alkali activation of fly ash as a sole precursor showed excellent strength retention after heating to temperatures from 100 to 800°C, and the post-cooling compressive strength increased by as much as 100% after exposure at 800°C due to densification and phase transformations. Partial substitution of slag for fly ash increased the strength of GFC at room temperature, but led to notable shrinkage and strength Preprint of: Z Zhang, JL Provis, A Reid, H Wang, Mechanical, thermal insulation, thermal resistance and acoustic absorption properties of geopolymer foam concrete (GFC), Cement and Concrete Composites, 62(2015): 97-105. Final published version is at: http://dx.doi.org/10.1016/j.cemconcomp.2015.03.013 2 loss at high temperature. Thin GFC panels (20 -25 mm) exhibited acoustic absorption coefficients of 0.7-1.0 at 40 to 150 Hz, and 0.1-0.3 at 800 to 1600 Hz.

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Section: Acoustic Absorptionmentioning

confidence: 72%

Mechanical, thermal insulation, thermal resistance and acoustic absorption properties of geopolymer foam concrete

Zhang

Provis

Reid³

et al. 2015

Cement and Concrete Composites

Self Cite

466

160

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“…It can be seen that AAS pastes accelerated with OPC and the combination of silica fume and slaked lime, have highly tortuous structures on nanoscale (Fig. 9C,D) which correlates with tortuosity of microstructure of alkali-activated binders found by Provis et al [42]. The control (Fig.…”

Section: Semmentioning

confidence: 76%

Chemical acceleration of a neutral granulated blast-furnace slag activated by sodium carbonate

Kovtun

Kearsley

Shekhovtsova

2015

Cement and Concrete Research

133

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This paper presents results of a study on chemical acceleration of a neutral granulated blastfurnace slag activated using sodium carbonate. As strength development of alkali-activated slag cements containing neutral GBFS and sodium carbonate as activator at room temperature is known to be slow, three accelerators were investigated: sodium hydroxide, ordinary Portland cement and a combination of silica fume and slaked lime. In all cements, the main hydration product is C-(A)-S-H, but its structure varies between tobermorite and riversideite depending on the accelerator used. Calcite and gaylussite are present in all systems and they were formed due to either cation exchange reaction between the slag and the activator, or carbonation. With accelerators, compressive strength up to 15 MPa can be achieved within 24 hours in comparison to 2.5 MPa after 48 hours for a mix without an accelerator.

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“…It appears from Figure 4 that the silage effluent has caused thicker zones of deterioration in sample GPp-B. This is likely due to higher porosity reported in mixes with a higher PFA content [37]. …”

Section: Methodsmentioning

confidence: 86%

Resistance of geopolymer and Portland cement based systems to silage effluent attack

Aiken

Sha

Kwasny

et al. 2017

Cement and Concrete Research

109

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Abstract:Traditional Portland cement (PC) concrete has been used for many years in the agricultural industry for the construction of silos and silage effluent storage facilities. However, the acidic nature of the silage effluent produced by silage has led to severe degradation of PC concrete which in turn has significant environmental and financial implications. This study compares the resistance of PC and geopolymer (GP) mortars and pastes to silage effluent over 12 months. The GP samples displayed increased resistance to silage effluent in terms of mass and strength loss. Analysis of microstructure suggests that the increased stability of the reaction products is the main factor behind increased silage effluent resistance when compared with PC. It was also found that pulverised fuel ash (PFA) and ground granulated blast furnace slag (GGBS) blends with a higher PFA content may offer increased long term silage effluent resistance due to the nature of the main binder gel produced in PFA dominant systems.

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X-ray microtomography shows pore structure and tortuosity in alkali-activated binders

Cited by 447 publications

References 38 publications

Mechanical, thermal insulation, thermal resistance and acoustic absorption properties of geopolymer foam concrete

Mechanical, thermal insulation, thermal resistance and acoustic absorption properties of geopolymer foam concrete

Chemical acceleration of a neutral granulated blast-furnace slag activated by sodium carbonate

Resistance of geopolymer and Portland cement based systems to silage effluent attack

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