Preparation of geopolymer concrete using Egyptian kaolin clay and the study of its environmental effects and economic cost

Abbas, Rafik; Khereby, Mona Aly; Ghorab, H. Y.; Elkhoshkhany, N.

doi:10.1007/s10098-020-01811-4

Cited by 114 publications

(43 citation statements)

References 55 publications

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“…Engineers and contractors did not embrace these alternate cements due to high costs [11], and they prefer strong materials and strict building standards [9,12,13]. Geopolymer cement (USD 161.00) costs nearly thrice as much as the Portland cement (USD 51.00) [14,15]. High costs and lack of field testing prohibit the use of these new cements.…”

Section: Novel Clinkers [7]mentioning

confidence: 99%

Decarbonising the Portland and Other Cements—Via Simultaneous Feedstock Recycling and Carbon Conversions Sans External Catalysts

Devasahayam

2021

Polymers

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The current overarching global environmental crisis relates to high carbon footprint in cement production, waste plastic accumulation, and growing future energy demands. A simultaneous solution to the above crises was examined in this work. The present study focused on decarbonizing the calcination process of the cement making using waste plastics and biowastes as the reactants or the feedstock, to reduce the carbon footprint and to simultaneously convert it into clean energy, which were never reported before. Other studies reported the use of waste plastics and biowastes as fuel in cement kilns, applicable to the entire cement making process. Calcination of calcium carbonate and magnesium carbonate is the most emission intensive process in cement making in Portland cements and Novacem-like cements. In the Novacem process, which is based on magnesium oxide and magnesium carbonates systems, the carbon dioxide generated is recycled to carbonate magnesium silicates at elevated temperatures and pressures. The present study examined the Novacem-like cement system but in the presence of waste plastics and biomass during the calcination. The carbon dioxide and the methane produced during calcination were converted into syngas or hydrogen in Novacem-like cements. It was established that carbon dioxide and methane emissions were reduced by approximately 99% when plastics and biowastes were added as additives or feedstock during the calcination, which were converted into syngas and/or hydrogen. The reaction intermediates of calcination reactions (calcium carbonate–calcium oxide or magnesium carbonate–magnesium oxide systems) can facilitate the endothermic carbon conversion reactions to syngas or hydrogen acting as non-soot forming catalysts. The conventional catalysts used in carbon conversion reactions are expensive and susceptible to carbon fouling. Two criteria were established in this study: first, to reduce the carbon dioxide/methane emissions during calcination; second, to simultaneously convert the carbon dioxide and methane to hydrogen. Reduction and conversion of carbon dioxide and methane emissions were facilitated by co-gasification of plastics and bio-wastes.

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Section: Novel Clinkers [7]mentioning

confidence: 99%

Decarbonising the Portland and Other Cements—Via Simultaneous Feedstock Recycling and Carbon Conversions Sans External Catalysts

Devasahayam

2021

Polymers

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“…As compared to the control mixture with a 20% replacement of cement, a significant reduction in global warming potential (GWP) by around 21% was achieved. Abbas and Khereby [59] recorded a 61% reduction in GWP as compared GPC with control mixtures. However, Abbas and Khereby [59] completely replaced the cement with metakaolin.…”

Section: Impact Of Gpc On Emission Reduction and Global Warming Potenmentioning

confidence: 92%

“…Abbas and Khereby [59] recorded a 61% reduction in GWP as compared GPC with control mixtures. However, Abbas and Khereby [59] completely replaced the cement with metakaolin.…”

Section: Impact Of Gpc On Emission Reduction and Global Warming Potenmentioning

confidence: 92%

Experimental Investigation of NaOH and KOH Mixture in SCBA-Based Geopolymer Cement Composite

et al. 2020

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This research aimed at exploring the effects of a mixture of sodium hydroxide (NaOH) and potassium hydroxide (KOH) activators in a sugar cane bagasse ash (SCBA)-based geopolymer cement paste. Bagasse ash replacement was 20% of cement by weight. The mixture of NaOH and KOH comprised 4, 8, and 12 M solutions with mixing percentages of 0%, 20%, 40%, 60%, 80%, and 100% for all possible combinations. A pH test was performed on each possible combination of solutions. A Chapelle’s test, XRD, X-ray fluorescence (XRF), and SEM analysis were used to check whether the SCBA exhibited pozzolanic reactivity. Subsequently, the SCBA geopolymer cement paste was tested for compressive strength, water absorption, permeable porosity, and sorptivity. It was estimated that the geopolymer cement paste exhibited higher absorption and sorptivity values than control mixtures when molarity increased. However, the samples prepared with combinations of the 8 M activator solution exhibited consistent absorption, sorptivity, and compressive strength values when compared to the control and other geopolymer mixtures with 4 and 12 M activator solutions. Thus, the two activator solutions G8N408K60 and G8N208K80—where GxNayKb represents the geopolymer concrete sample prepared by adding solutions of two bases, i.e., ‘xNayKb’ showing an ‘a’ percentage of ‘x’ molar NaOH and a ‘b’ percentage of ‘y’ molar KOH—were obtained as the optimum molar ratio of the activator in geopolymer concrete. The geopolymer cement pastes, along with the optimum and control samples, were further tested for concrete durability, SEM, and TGA tests. The G8N208K80 sample exhibited a better mechanical and durability performance than the G8N408K60 sample. The durability performance of the geopolymer concrete was also superior to ordinary concrete. Moreover, the geopolymer concrete achieved a 21% reduction in global warming potential compared to the control mixture. Thus, it can be concluded that the use of SCBA ash in geopolymer concrete can address the ash disposal and CO2 emission problems with enhanced durability.

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“…The environmental impact depends on the internal chemical composition of binder and is influenced by the amount of silicate. For example, the binder that requires high amount of sodium silicate has higher impact of GWP [216,221]. Heath et al [216] found that FA and GGBFS has lower CO 2 production and GWP than MK as MK requires more amount of silicates as an activator.…”

Section: Gwp Calculation and Assessmentmentioning

confidence: 99%

A Review of Recent Developments and Advances in Eco-Friendly Geopolymer Concrete

et al. 2020

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The emission of CO2 and energy requirement in the production of Ordinary Portland Cement (OPC) causes the continuous depletion of ozone layer and global warming. The introduction of geopolymer concrete (GPC) technology in the construction industry leads to sustainable development and cleaner environment by reducing environmental pollution. In this article, constituents of GPC and their influence on properties of GPC has been reviewed critically. Fresh and hardened properties of GPC as well as the factors influencing these properties are discussed in detail. Flow charts have been proposed to show which factors have higher/lower impact on the fresh and hardened properties of GPC. A comprehensive review on the mix design of GPC, nanomaterial-based GPC, 3D printing using GPC, reinforced GPC and Global warming potential (GWP) assessment was conducted. Finally, the practical applications of GPC in the construction industry are provided.

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Preparation of geopolymer concrete using Egyptian kaolin clay and the study of its environmental effects and economic cost

Cited by 114 publications

References 55 publications

Decarbonising the Portland and Other Cements—Via Simultaneous Feedstock Recycling and Carbon Conversions Sans External Catalysts

Decarbonising the Portland and Other Cements—Via Simultaneous Feedstock Recycling and Carbon Conversions Sans External Catalysts

Experimental Investigation of NaOH and KOH Mixture in SCBA-Based Geopolymer Cement Composite

A Review of Recent Developments and Advances in Eco-Friendly Geopolymer Concrete

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