Improving compressive strength of fly ash-based geopolymer composites by basalt fibers addition

Timakul, Patthamaporn; Rattanaprasit, Weerada; Aungkavattana, Pavadee

doi:10.1016/j.ceramint.2016.01.014

Cited by 123 publications

(45 citation statements)

References 23 publications

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“…The increase in the intensity of Ca bar was observed on the samples with increasing GGBS in the matrix, which led to the increased Ca/Si ratio. This suggests that the highest Ca/Si ratio promoted the C-S-H bond formation, which filled the open voids resulting in reduced porosity, and increased strength [47]. However, the Ca/Si ratio for samples activated with NaOH + Na 2 SiO 3 (CemN.C), as shown in Figure 9d-f, was comparatively less, but the strength was higher than NaOH (Cem.C) activated samples, Figure 9a-c.…”

Section: Sem-eds Point Analysesmentioning

confidence: 94%

“…It is a result of excessive load applied on the sample to obtain the mini samples for SEM analyses. filled the open voids resulting in reduced porosity, and increased strength [47]. However, the Ca/Si ratio for samples activated with NaOH + Na2SiO3 (CemN.C), as shown in Figure 9d-f, was comparatively less, but the strength was higher than NaOH (Cem.C) activated samples, Figure 9a-c.…”

Section: Sem Micrographsmentioning

confidence: 99%

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Strength and Microstructure of Class-C Fly Ash and GGBS Blend Geopolymer Activated in NaOH & NaOH + Na2SiO3

et al. 2019

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In this paper, class-C fly ash (FA) and ground granulated blast-furnace slag (GGBS)-based geopolymer activated in NaOH and NaOH + Na 2 SiO 3 was studied regarding setting time, compressive strength, porosity, microstructure, and formation of crystalline phases. When comparing the effects of alkali type on the FA and GGBS geopolymer composites, results revealed that NaOH has a lesser effect in developing strength and denser microstructure than does NaOH + Na 2 SiO 3, since the addition of Na 2 SiO 3 provides the silica source to develop more compact structure. Incorporation of Na 2 SiO 3 reduced the crystallinity and the paste was more amorphous compared to NaOH activated pastes. The class-C FA and GGBS blends resulted in prolonged setting time, reduced strength, and loose matrix with the increase in fly ash content. The un-reactivity of calcium in blends was observed with increasing fly ash content, leading to strength loss. It is evident from XRD patterns that calcium in fly ash did not contribute in forming C-S-H bond, but formation of crystalline calcite was observed. Furthermore, XRD analyses revealed that the reduction in fly ash leads to the reduction in crystallinity, and SEM micrographs showed the unreactive fly ash particles, which hinder the formation of a denser matrix.Materials 2020, 13, 59 2 of 15 is also formed in Portland cement. Its formation leads to short setting time, reduced porosity, and increased compressive strength [9,10].Fly ash has been investigated as a precursor material in geopolymer mortar. The mechanical properties of fly ash-based geopolymer depends on the chemical composition of fly ash. As explored by Davidovits, Izquierdo [11] in their study, the fly ash containing low calcium (class-F) produced a workable geopolymer; however, the high calcium in fly ash did not contribute in producing the suitable geopolymer due to flash setting time. The flash setting time in the high-calcium fly ash was confirmed in studies [12,13] where they used borax in the mixture to delay the setting time. However, regardless of this problem, the class-C fly ash has been found to help improve the strength properties due the presence of adequate calcium content, which may forms C-S-H gel in the matrix [14].Ground granulated blast-furnace slag (GGBS) is another by-product material rich in amorphous calcium, silica, and alumina, which makes it suitable to be used as a binder in the construction industry [15]. Formerly, GGBS as a precursor material in geopolymer has been investigated. It is worth mentioning that the GGBS activated in alkali solution possess a high strength and good resistance to the chemicals compared to Portland cement. However, the reduced setting time makes it susceptible to high shrinkage and develops micro cracks, which increases the porosity leading to the strength loss [16]. Since the GGBS is rich in calcium, the main reaction product is C-S-H gel, which may coexist with the geopolymer gel depending on the chemical composition of the GGBS, alkali type, and alkali amount [4,17,18].The ...

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Section: Sem-eds Point Analysesmentioning

confidence: 94%

Section: Sem Micrographsmentioning

confidence: 99%

Strength and Microstructure of Class-C Fly Ash and GGBS Blend Geopolymer Activated in NaOH & NaOH + Na2SiO3

et al. 2019

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“…Most frequently granular fillers are used for this purpose, such as silica sand [24], calcite and dolomite sand [25], grinded electrical porcelain [26], grinded high-alumina refractory brick [27], aAl 2 O 3 powder [28], a-quartz sand and fine alumina powder [29], chamotte powder [30], kyanite (nesosilicate) aggregates [31], cordierite powder [32], burned clay [33], expanded clay [34], quartz fume [35]. Besides, fiber reinforcement was applied such as SiC fibers [36], basalt fibers [37], also steel or polymer fibers [38]. This research revealed variations in residual mechanical strength and thermal behavior of the filler and/or reinforced thermally exposed composites.…”

Section: Introductionmentioning

confidence: 99%

Thermomechanical properties of particle-reinforced geopolymer composite with various aggregate gradation of fine ceramic filler

Kovařík

Rieger

Kadlec

et al. 2017

Construction and Building Materials

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“…Results show that MSF has strong contact with the matrix because it tends to behave as a hydrophilic material, while PPF led to fiber-matrix debonding due to hydrophobic characteristics. Timakul et al [20] reported the addition of basalt fibers into the fly ash-based geopolymer can improve its compressive strength. Lin et al [14,[21][22] prepared the short carbon fiber geopolymer matrix composites using sheetlike fiber preform, and improved the mechanical properties.…”

Section: Introductionmentioning

confidence: 99%

“…However, the pure geopolymers showed disadvantages of both low mechanical performance and catastrophic fracture behavior, thus limits its applications as structural components [1][2][3][4][5][6][7]. In recent years, many studies have been explored on geopolymer matrix composites to overcome the disadvantages of itself low strength and brittle failure, including nanotube [8,9], graphene [10][11], particles [12][13], short fiber [14][15][16]20] and continuous fiber [17][18][19]. Ranjbar [19] evaluated fiber-matrix interaction and mechanical properties of two different fibers (polypropylene (PPF) and micro steel fibers (MSF)) reinforced fly ash based geopolymer.…”

Section: Introductionmentioning

confidence: 99%

Preparation and mechanical performance of Cf-SiCf-(Al₂O₃p) reinforced geopolymer composites

Yan

Jia

et al. 2017

MATEC Web Conf.

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Abstract. The C f -SiC f -(Al 2 O 3p )/KGP composites were successfully prepared by the method that mixing a kind of hybrid fiber preform predeveloped and geopolymer resin. The synergistic effects of the hybrid fibers and Al 2 O 3 particles on the composites were investigated. Results show that all the composites showed typical amorphous structure. Mechanical properties of the C f -SiC f -(Al 2 O 3p )/KGP composites were improved remarkably due to the addition of the hybrid fibers and Al 2 O 3 particles. The flexural strength and Young s modulus of the C f -SiC fAl 2 O 3p /KGP composites with 1 mm length SiC f were reached 62.4±2.1 MPa and 24.1±1.6 GPa, respectively. The C f -SiC f -(Al 2 O 3p )/KGP composites showed non-catastrophic behavior rather than the catastrophic failure.

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Improving compressive strength of fly ash-based geopolymer composites by basalt fibers addition

Cited by 123 publications

References 23 publications

Strength and Microstructure of Class-C Fly Ash and GGBS Blend Geopolymer Activated in NaOH & NaOH + Na2SiO3

Strength and Microstructure of Class-C Fly Ash and GGBS Blend Geopolymer Activated in NaOH & NaOH + Na2SiO3

Thermomechanical properties of particle-reinforced geopolymer composite with various aggregate gradation of fine ceramic filler

Preparation and mechanical performance of Cf-SiCf-(Al₂O₃p) reinforced geopolymer composites

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Improving compressive strength of fly ash-based geopolymer composites by basalt fibers addition

Cited by 123 publications

References 23 publications

Strength and Microstructure of Class-C Fly Ash and GGBS Blend Geopolymer Activated in NaOH & NaOH + Na2SiO3

Strength and Microstructure of Class-C Fly Ash and GGBS Blend Geopolymer Activated in NaOH & NaOH + Na2SiO3

Thermomechanical properties of particle-reinforced geopolymer composite with various aggregate gradation of fine ceramic filler

Preparation and mechanical performance of Cf-SiCf-(Al2O3p) reinforced geopolymer composites

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Preparation and mechanical performance of Cf-SiCf-(Al₂O₃p) reinforced geopolymer composites