Reactivity and reaction products of alkali-activated, fly ash/slag paste

Lee, Namkon; Lee, Haeng‐Ki

doi:10.1016/j.conbuildmat.2015.02.022

Cited by 229 publications

(85 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…This is due to GPp-B having a higher PFA content and PFA having a higher aluminium content compared with GGBS. These values are similar with those in literature [42], [62] and [63]. At the outside layer of each sample the Ca/Si ratio is greatly reduced due to silage effluent attack.…”

Section: Mass Losssupporting

confidence: 80%

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

Aiken

Sha

Kwasny

et al. 2017

Cement and Concrete Research

108

View full text Add to dashboard Cite

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.

show abstract

Section: Mass Losssupporting

confidence: 80%

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

Aiken

Sha

Kwasny

et al. 2017

Cement and Concrete Research

108

View full text Add to dashboard Cite

show abstract

“…The alkali-activator used for the slag-blended geopolymer matrix was composed with a mixture of a 4M NaOH solution and a sodium silicate solution at a weight ratio of 2:1. The concentrations of the activators were determined considering the degree of geopolymerization and the mechanical properties reported in previous studies [21,22,24]. The Portland cement matrix was produced from a mixture of cement and water at a weight ratio of 2:1.…”

Section: Preparation Of Waste Form Simulantsmentioning

confidence: 99%

Physical barrier effect of geopolymeric waste form on diffusivity of cesium and strontium

Jang

Park

2016

Journal of Hazardous Materials

Self Cite

View full text Add to dashboard Cite

“…Thermal power is an indicator of the rate of the chemical reactions occurring between cementitious materials and water and admixtures. The main hydration peak (associated mainly with hydration reactions) is an indicator of setting and early strength development of the mixture [48,49]. The heat flow peaks were variable with different GGBS/binder ratio mixtures: the main thermal peaks of the geopolymer pastes were 0.0129 mW/mg, 0.02 mW/mg, 0.0414 mW/mg and 0.034 mW/mg for 20 %, 30 %, 40 % and 50 % GGBS to binder ratios.…”

Section: Thermal Analysis (Dsc)mentioning

confidence: 99%

Development of geopolymer mortar under ambient temperature for in situ applications

Al-Majidi

Λαμπρόπουλος

Cundy

et al. 2016

Construction and Building Materials

305

View full text Add to dashboard Cite

Geopolymer concrete technology involves production of more environmentally friendly waste material-based concrete which could be a viable solution for conventional concrete replacement. Typical fly ash-based geopolymer concrete however requires high temperature curing treatment in order to develop sufficient early strength properties, which is considered a severe limitation for cast-in-place concrete applications. Most previous studies on geopolymer concrete have focused on the properties of concretes pre-hardened by heat curing and/ or by aggressive chemical treatment (e.g. alkali activation using concentrated sodium hydroxide (NaOH)). The current study presents an extensive experimental investigation on the mechanical and microstructural properties of geopolymer concrete mixes prepared with a combination of fly ash and slag cured under ambient temperature. 'User friendly' geopolymer mixes were produced using fly ash (FA) and Ground Granulated Blast furnace Slag (GGBS) mixed together with potassium silicate with molar ratio equal to 1.2 (as the activator) and water. The results indicated that heat curing treatment can be avoided by partial replacement of fly ash with slag. The compressive strength of the examined mixes was found to be in the range of 40-50MPa for 40 % and 50 % GGBS replacement mixtures respectively. Moreover, the flexural and direct tensile strengths of geopolymer mixes are considerably improved as the GGBS content is increased.Based on FTIR and SEM/EDS analysis, the inclusion of a higher content of GGBS resulted in a denser structure by formation of more hydration products.Keywords: Fly ash, slag, ambient temperature, user friendly geopolymer mortar *Manuscript Click here to view linked References 2 IntroductionThere are many environmental issues associated with the production of Ordinary Portland cement (OPC), such as consumption of 5% of natural resources, and generation of 5-7 % of total global anthropogenic carbon dioxide emissions [1][2][3][4]. This has led to an urgent need for the development of alternative materials that may provide technically viable alternative solutions to conventional cementitious concrete, with more favourable environmental credentials. Geopolymer concrete manufacture is one of the most promising techniques which has been developed in the last few years. Utilization of geopolymer materials can reduce 80% of greenhouse gas emissions associated with material production, and overcome issues related to cement production and unregulated disposal of industrial materials by recycling these materials in geopolymer manufacture [5][6][7].Geopolymers are inorganic by-product materials, rich in silicon (Si) and aluminium Five different mixtures of geopolymer mortar proportions were examined with various ratios of GGBS to total binder (10%, 20%, 30%, 40% and 50 %, Table 2). Based on preliminary experimental studies undertaken during the current project, the optimum mix design (in terms of mechanical strength and workability) was achieved using water, alkaline activator...

show abstract

Reactivity and reaction products of alkali-activated, fly ash/slag paste

Cited by 229 publications

References 44 publications

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

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

Physical barrier effect of geopolymeric waste form on diffusivity of cesium and strontium

Development of geopolymer mortar under ambient temperature for in situ applications

Contact Info

Product

Resources

About