Milestones in the analysis of alkali-activated binders

Provis, John L.; Bernal, Susan A.

doi:10.1080/21650373.2014.958599

Cited by 20 publications

(12 citation statements)

References 47 publications

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“…e development of alkali-activated materials (AAMs) has been in the focus of interest over the last few decades [1][2][3][4][5]. Alkali-activated slag (AAS) and AASC (alkali-activated slag concrete) are made by activating granulated blast furnace slag (GGBS) with alkali solutions.…”

Section: Introductionmentioning

confidence: 99%

Autogenous Deformation of Alkali‐Activated Blast Furnace Slag Concrete Subjected to Variable Curing Temperatures

Orosz

Humad

Hedlund

et al. 2019

Advances in Civil Engineering

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Deformations of alkali-activated slag concrete (AASC) with high MgO and Al2O3 content, subjected to variable curing temperature were studied. Sodium silicate and sodium carbonate were used as alkali activators. The obtained results showed development of deformations consisting of both shrinkage and expansion. Shrinkage appeared not to be affected by the activator type, while the expansion developed after the cooling down phase in stabilized isothermal conditions and did not stop within the duration of the tests. X-ray diffraction analysis performed shortly after the cooling down phase indicated the formation of crystalline hydrotalcite, which was associated with the observed expansion. A mixture with a higher amount of sodium silicate showed less expansion, likely due to the accelerated hydration and geopolymerization leading to the increased stiffness of the binder matrix.

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Section: Introductionmentioning

confidence: 99%

Autogenous Deformation of Alkali‐Activated Blast Furnace Slag Concrete Subjected to Variable Curing Temperatures

Orosz

Humad

Hedlund

et al. 2019

Advances in Civil Engineering

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“…Alkali-activated (AA) materials have been widely investigated in recent years (Provis and Bernal, 2014;Provis et al, 2015;Luukkonen et al, 2018;Provis, 2018) within the context of the construction and building industry. More specifically, research in the area of sintered and non-sintered foam materials, based on the process of alkali activation, is currently extremely active (Zhao et al, 2010;Chen et al, 2011;Hajimohammadi et al, 2017a;Rabelo Monich et al, 2018;Rincon, 2019).…”

Section: Introductionmentioning

confidence: 99%

Characterization of Fly Ash Alkali Activated Foams Obtained Using Sodium Perborate Monohydrate as a Foaming Agent at Room and Elevated Temperatures

Korat¹,

Ducman²

2020

Front. Mater.

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Alkali activated foams have been extensively studied in recent years, due to their high performance and low environmental footprint compared to foams produced via other methods. Three types of fly ash differing in chemical and mineralogical composition and specific surface were used to synthesize alkali activated foams. Sodium perborate monohydrate was added as a foaming agent and sodium dodecyl sulphate as a stabilizing agent. Foams were characterized at room temperature and after exposure to an elevated temperature (1,000°C). Densities from 1.2 down to 0.3 g/cm 3 were obtained, depending on the type of fly ash and quantity of foaming agent added. Correspondingly, compressive strength ranged from 1 to 6 MPa. Comparing all three fly ashes the most favorable results, in terms of density and corresponding compressive strength, were achieved from the fly ash with the highest amounts of SiO 2 and Al 2 O 3 , as well as the highest amorphous phase content i.e., RI fly ash. Furthermore, after firing to 1,000°C, the density of samples prepared using fly ash RI remained approximately the same, while the compressive strength increased on average by 50%. In the other two types of fly ash the density increased slightly after firing, due to significant shrinkage, and compressive strength increased by as much as 800%. X-ray powder diffraction analysis confirmed the occurrence of a crystallization process after firing to 1,000°C, which resulted in newly formed crystal phases, including nepheline, sodalite, tridymite, and gehlenite.

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“…Geopolymer is produced by activating fly ash with high silicate materials that could bind aggregates as concrete. Geopolymer concrete has higher resistance to chloride, acid, sulfate and high temperature than the OPC concrete [9,10]. The previous study shows that fly ash geopolymeric material in peat environment was transformed into different material with moderate resistance to acid attack.…”

Section: Introductionmentioning

confidence: 99%

Early strength of various fly ash based concrete in peat environment

2019

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Fly ash is a by-product of coal combustion in a power station and usually used as additive or cement replacement material to improve properties of concrete in aggressive environments such as acid, chloride, and sulphate. Peatland is one of acidic environment that is common in Riau province with high organic content and low pH that is damaging for concrete, especially when exposed to concrete at an early age. This paper aims to study the early compressive and tensile strength of the various type of fly ash based concrete subjected to peat water. Seven fly ash-based concrete mixtures investigate were, i.e., geopolymer hybrid using 15% of Ordinary Portland Cement (OPC) as an additive, high volume fly ash using 25%, 50% and 75% of fly ash as cement replacement material, and blended OPC with fly ash with different grade of 15, 21 and 29 MPa. The OPC concrete with a target strength of 20 MPa was a control mix. The OPC based-specimens were cast and cured in water for 28 days before placed in peat water for another 28 days before the testing date. Compressive strength and tensile strength values of the concrete at 7 and 28 days were taken. Results show the type of concrete, fly ash content, and concrete grade significantly influence the early strength properties and resistance of the concrete to the acid attack. Four concrete mixtures with decreasing vulnerability to the attack were distinguished: OPC, high volume fly ash, geopolymer hybrid and blended cement concrete.

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Milestones in the analysis of alkali-activated binders

Cited by 20 publications

References 47 publications

Autogenous Deformation of Alkali‐Activated Blast Furnace Slag Concrete Subjected to Variable Curing Temperatures

Autogenous Deformation of Alkali‐Activated Blast Furnace Slag Concrete Subjected to Variable Curing Temperatures

Characterization of Fly Ash Alkali Activated Foams Obtained Using Sodium Perborate Monohydrate as a Foaming Agent at Room and Elevated Temperatures

Early strength of various fly ash based concrete in peat environment

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