The fire resistance of alkali-activated cement-basedconcrete binders

Panias, Dimitrios; Balomenos, Efthymios; Sakkas, Konstantinos

doi:10.1533/9781782422884.3.423

Cited by 15 publications

(21 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The geopolymers were prepared by the mechanical mixing of CS with the KOH solution to form a homogeneous and viscous paste. Potassium was selected instead of sodium as the alkali of the activator, given that the potassium based geopolymers have larger potential for developing fire resistant materials, due to the formation of crystalline phases with high liquidus temperature [17]. The quantities of slag and KOH solution were selected so as to produce a geopolymeric paste with solid to liquid ratio equal to 6 g/mL, achieving homogeneity and at the same time smooth foaming, in case that the foaming agent (Al powder) was used.…”

Section: Synthesis Of Geopolymersmentioning

confidence: 99%

Upgrading Copper Slags to Added Value Fire Resistant Geopolymers

Miltiadis

Giannopoulou

Tahir

et al. 2019

Waste Biomass Valor

View full text Add to dashboard Cite

In this paper, the development of fire-resistant geopolymers for the passive fire protection of buildings is investigated. The fire-resistant geopolymeric materials were based on the alkali activation of a metallurgical slag produced in primary copper industry with a highly alkaline solution of potassium hydroxide. In order to decrease the density of the developed geopolymers, their foaming or the addition of lightweight aggregates was also studied. The physical, mechanical and thermal properties of the developed materials were determined and their performance upon exposure to fire was tested according to the ISO-834 standard time-temperature curve, which is considered as appropriate for testing fire protection systems employed in buildings. During the whole test of the materials performance against fire, the temperature at the interface between concrete and geopolymer was recorded below 180 °C, as required by the ISO test followed, proving effectiveness for the developed materials to be used as a thermal barrier in buildings and constructions. After testing, the geopolymers kept their structural integrity, without presenting any significant macroscopic damage.

show abstract

Section: Synthesis Of Geopolymersmentioning

confidence: 99%

Upgrading Copper Slags to Added Value Fire Resistant Geopolymers

Miltiadis

Giannopoulou

Tahir

et al. 2019

Waste Biomass Valor

View full text Add to dashboard Cite

show abstract

“…The alkaline activation of aluminosilicate raw materials is widely used in the production of modern building materials [11]. Concrete based on the alkaline-activated types of cement is characterized by the increased indicators of strength [12], heat resistance [13], corrosion resistance [14], sulfate resistance [15], frost resistance [16], water resistance [17], compared to analogs based on conventional clinker concrete. Along with the high performance properties, the alkaline-activated slag cement can be used as a base of decorative materials [18].…”

Section: Literature Review and Problem Statementmentioning

confidence: 99%

Design of slag cement, activated by Na (K) salts of strong acids, for concrete reinforced with steel fittings

Kryvenko

Rudenko

Konstantynovskyi

2020

EEJET

View full text Add to dashboard Cite

“…The typical chemical composition of the slag produced during the thermochemical conversion of municipal and mined wastes can be described as a CaO-FeO x -Al 2 O 3 -SiO 2 quaternary system, which sometimes also contains a significant MgO content [8]. This chemical composition could be adjusted to promote the formation of more refractory phases upon thermal exposure, i.e., by adding alumina-rich materials [7,9,10], but changing the composition of such low-value raw material may entail undesirable environmental and economic costs. Considering the above, the present work did not aim to enhance the thermal properties of CaO-FeO x -Al 2 O 3 -SiO 2 -rich AAMs by altering their chemical composition with beneficial admixtures but rather to characterize the thermal performance of potassium-based AAMs previously optimized for general construction purposes.…”

Section: Introductionmentioning

confidence: 99%

“…These phases comprise albite (Na feldspar, NaAlSi 3 O 8 or Na 2 O•Al 2 O 3 •6SiO 2 , having a liquidus temperature, 1118 • C), nepheline (Na-K feldspathoid, Na 3 KAl 4 Si 4 O 16 , stable up to 1256 • C), and carnegieite (Na feldspathoid, NaAlSiO 4 or Na 2 O•Al 2 O 3 •2SiO 2 , having a liquidus temperature, 1526 • C) in the case of sodium-based activators. In the case of potassium-based activators, the developed alumino-silicate compounds exhibit even higher melting points, as in the case of orthoclase (K feldspar, KAlSi 3 O 8 or K 2 O•Al 2 O 3 •6SiO 2 , having a liquidus temperature of 1250 • C), leucite (K feldspathoid, KAlSi 2 O 6 or Na 2 O•Al 2 O 3 •4SiO 2, with a congruent melting point of 1693 • C), and kalsilite (K feldspathoid, KAlSiO 4 or K 2 O•Al 2 O 3 •2SiO 2 , having a liquidus temperature, 1750 • C) [10].…”

Section: Introductionmentioning

confidence: 99%

High-Temperature Behavior of CaO-FeOx-Al2O3-SiO2-Rich Alkali Activated Materials

et al. 2022

View full text Add to dashboard Cite

Alkali-activated materials (AAMs) provide an opportunity to up-cycle several residues into added-value materials. Although generally praised for their performance under thermal loads, the thermal behavior of AAMs is dictated by a multitude of factors and the performance of CaO-FeOx-rich systems may differ from geopolymers. Therefore, this work ascertains the high‑temperature resistance of CaO‑FeOx-Al2O3-SiO2-rich AAMs. Mortars were exposed to different heating rates (≤10 °C/min) and temperatures (≤1100 °C), and volume and mass loss, apparent density, compressive strength (CS), mineralogical composition, and morphology were evaluated. At low heating rates, the main effects noted were densification and a gradual lightening of color as the temperature rose. CS underwent an abrupt decline at 750 °C and recovered at higher temperatures, reaching a maximum value of 184 ± 13 MPa at 1100 °C. With an increased heating rate to 10 °C/min, the strength loss at 750 °C persisted, but maximum CS was halved when firing at 900 °C. At 1100 °C, a significant reduction of CS was observed, but all samples maintained their integrity. Except for 1100 °C at 10 °C/min, all sintered-AAMs presented residual CS above 40 MPa. These results demonstrate that CaO-FeOx-Al2O3-SiO2-rich AAMs present interesting thermal behavior and can be potentially used to produce glass-ceramics or refractory materials from secondary resources.

show abstract

The fire resistance of alkali-activated cement-basedconcrete binders

Cited by 15 publications

References 20 publications

Upgrading Copper Slags to Added Value Fire Resistant Geopolymers

Upgrading Copper Slags to Added Value Fire Resistant Geopolymers

Design of slag cement, activated by Na (K) salts of strong acids, for concrete reinforced with steel fittings

High-Temperature Behavior of CaO-FeOx-Al2O3-SiO2-Rich Alkali Activated Materials

Contact Info

Product

Resources

About