Synthesis and thermal properties of inorganic polymers (geopolymers) for structural and refractory applications from volcanic ash

Lemougna, Patrick N.; MacKenzie, Kenneth J.D.; Melo, U. F. Chinje

doi:10.1016/j.ceramint.2011.05.002

Cited by 228 publications

(104 citation statements)

References 27 publications

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“…Thus, this phenomenon contributes to the formation of more stable and stronger structures compared with simple systems as a result of the simultaneous formation of the geopolymeric network and C-S-H gel. This finding correlates with the highest mechanical strengths that have been attained by binary blends (8,(25)(26)(27)(28). The setting times of the different geopolymer samples, which are considered an indicator of the kinetics of the geopolymerisation reactions (23), are shown in Table 5, which shows evidence that the incorporation of GBFS and its proportion in binary systems (NP+GBFS) reduces the initial and final setting times of the simple system (NP).…”

Section: Geopolymerisation Kineticsmentioning

confidence: 62%

Natural pozzolan-and granulated blast furnace slag-based binary geopolymers

Robayo¹,

Gutiérrez²,

Gordillo³

2016

Mater. construcc.

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This study describes the synthesis at ambient temperature (25±3 °C) of binary geopolymer systems based on natural volcanic pozzolan and granulated blast furnace slag. Na 2 SiO 3 and NaOH were used as alkaline activators. The effects of the SiO 2 /Al 2 O 3 , Na 2 O/Al 2 O 3 ratio and the amount of slag added (from 0 to 30%) on the reaction kinetics, compressive strength and microstructure of the final product were studied. To characterise the geopolymer pastes, techniques such as X-ray diffraction (XRD), infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were used. The results indicate the possibility of obtaining a geopolymer cement with a compressive strength of up to 48.11 MPa after 28 days of curing at ambient temperature whose characteristics are comparable to those of commercial portland cement. RESUMEN: Geopolímeros de tipo binario basados en una puzolana natural y escoria siderúrgica de alto horno.Este trabajo describe la síntesis a temperatura ambiente (25±3 °C) de sistemas geopoliméricos de tipo binario basados en una puzolana natural de origen volcánico y escoria siderúrgica de alto horno usando activadores alcalinos basados en la combinación de Na 2 SiO 3 y NaOH. Se estudió el efecto de la relación SiO 2 /Al 2 O 3 , Na 2 O/ Al 2 O 3 y la cantidad de escoria adicionada en niveles entre el 0 y 30% sobre la cinética de reacción, la resistencia a la compresión y la microestructura del producto final. Para la caracterización de las pastas geopoliméricas se utilizaron técnicas como difracción de rayos X (DRX), espectroscopia infrarroja (FTIR) y microscopia electró-nica de barrido (MEB). Los resultados conseguidos revelan la posibilidad de obtener un cementante geopolimérico con una resistencia a la compresión de hasta 48,11 MPa a los 28 días de curado a temperatura ambiente cuyas características son comparables a las de un cemento portland comercial.

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Section: Geopolymerisation Kineticsmentioning

confidence: 62%

Natural pozzolan-and granulated blast furnace slag-based binary geopolymers

Robayo¹,

Gutiérrez²,

Gordillo³

2016

Mater. construcc.

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“…Although some other dilatometric studies [38,39] also showed a similar small expansion before 100°C, a certain extent of shrinkage is normally observed at 100°C when starting from as-cured (moist) samples [32,34,35,40]. The small expansion before 100°C observed in some research is probably due to the thermal expansion properties of the solid geopolymer gel.…”

Section: Thermal Resistancementioning

confidence: 89%

“…The small expansion before 100°C observed in some research is probably due to the thermal expansion properties of the solid geopolymer gel. Lemougna et al [40] reported the dilatometric study of dense geopolymers, showing consistent shrinkage from room temperature to 800°C. They also calculated the thermal expansion coefficient, which is around 12×10 -6 /°C, by measuring the expansion rate of post-heated samples in a second heating cycle.…”

Section: Thermal Resistancementioning

confidence: 99%

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

Zhang

Provis

Reid³

et al. 2015

Cement and Concrete Composites

443

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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“…For this reason, different inorganic particles such as Al 2 O 3 [8], TiO 2 , ZnO, and SiC [9] have been melt-blended with PPS matrix. Volcanic ash (VA), which is deposited at the surface during volcanic activity, is readily accessible and has the advantage that it can be economically mined, with enormous benefits of low cost and limited negative environmental impact compared with traditional open pit quarry-type clay mining [10,11]. VA, known as mesoporous material, has high specific surface area, significant porosity and an appropriate pore structure, which enhances its possibility to be filled in PPS.…”

Section: Introductionmentioning

confidence: 99%

Effect of Silane as Coupling Agent on Dynamic Mechanical Properties of Volcanic Ash Filled PPS Composites

et al. 2016

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The purpose of this study is to investigate the effect of surface modification of volcanic ash particles on dynamic mechanical properties of volcanic ash filled polyphenylene sulfide (PPS) composites. For this purpose volcanic ash particles were modified with 1, 3, 5 vol.% of 3-aminopropyltriethoxysilane (3-APTS) which has an organic functional group. All volcanic ash/PPS composite samples were prepared by using DSM Xplore 15 ml twin screw microcompounder and DSM Xplore 12 ml injection molding machines. The content of volcanic ash in composite samples was varied as 10 and 15 wt%. Volcanic ash filler dispersion and adhesion between volcanic ash particles and PPS matrix were examined by scanning electron microscopy. Dynamic mechanical properties such as storage modulus (E ) and glass transition temperature (Tg) were investigated by TA Instruments Q800 dynamic mechanical analyzer. During the experiments, the relation between silane coupling and dynamic mechanical properties was evaluated.

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Synthesis and thermal properties of inorganic polymers (geopolymers) for structural and refractory applications from volcanic ash

Cited by 228 publications

References 27 publications

Natural pozzolan-and granulated blast furnace slag-based binary geopolymers

Natural pozzolan-and granulated blast furnace slag-based binary geopolymers

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

Effect of Silane as Coupling Agent on Dynamic Mechanical Properties of Volcanic Ash Filled PPS Composites

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