Influence of granulated blast furnace slag on the reaction, structure and properties of fly ash based geopolymer

Kumar, Sanjay; Kumar, Rakesh; Mehrotra, Shanta

doi:10.1007/s10853-009-3934-5

Cited by 657 publications

(290 citation statements)

References 37 publications

Supporting

Mentioning

257

Contrasting

Unclassified

Order By: Relevance

“…The lowest initial setting times were obtained for the pure GGBS, which corresponded to the highest Ca content ( Figure 5 (c) and (d)). This is in agreement with the findings of Kumar et al [38] and Gao et al [16]. Ca is easily converted into Ca 2+ ions, which quickly associate with the silicates coming from the alkaline solution to produce C-A-S-H. A gradient of Ca 2+ concentration appears between the solution and the GGBS particles, promoting the dissolution of Ca into the solution.…”

Section: Sample Production and Characterizationsupporting

confidence: 92%

“…GGBS-FA AAMs (paste [38][39][40][41][42][43], mortar [16,43,44] or concrete [45]) were also investigated. Kumar et al [38] revealed that at 27°C, the reaction of alkali-activated GGBS-FA blend paste is dominated by the GGBS activation (dissolution and precipitation of C-A-S-H) while at 60°C the reaction is due to combined interaction of FA and GGBS, which indicates that FA has lower reactivity than GGBS under ambient conditions. There is only small interaction of fly ash and GGBS probably due to different kinetics of dissolution process and distribution of species.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Formulation and characterization of blended alkali-activated materials based on flash-calcined metakaolin, fly ash and GGBS

Samson

Cyr

Gao

2017

Construction and Building Materials

View full text Add to dashboard Cite

Highlights AAMs initial setting time, shrinkage, mass loss, compressive strength were studied. Low activation leads to high drying shrinkage because of important mass loss. Very low shrinkage values were found for MK-GGBS compared to the other AAMs. High early strength compressive strength was observed for MK-GGBS blends. Graphical abstract 2 AbstractStudies performed on alkali-activated materials (AAMs) in recent years reveal that they could be an alternative to ordinary Portland cement (OPC). The main precursors used are flash-calcined metakaolin (MK), fly ash (FA), and ground granulated blast furnace slag (GGBS). Usually, only one precursor is used to produce an AAM. The aims of this study were to measure and compare the performances of pure (one precursor) and blended AAMs (two precursors). Alkaline solution is added to activate the precursors and the influence of the activation rate was also investigated by changing the activator amount (15% and 25% of alkaline solution dry extract). Twenty-six different mixes were studied and are presented in a ternary representation. The mixtures were characterized in the fresh state (initial setting time) and the main properties useful for building applications (shrinkage, mass loss, and compressive strength) were recorded and analysed. In contrast to the situation in OPC systems, shrinkage and mass loss in AAMs were not directly correlated. The high shrinkage values observed for pure MK AAMs and pure GGBS AAMs were significantly reduced when they were associated in appropriate proportions. The association of MK and GGBS also proved very interesting regarding early age compressive strength.Keywords: Alkali-activated material (AAM), metakaolin (MK), fly ash (FA), ground granulated blast furnace slag (GGBS), compressive strength, shrinkage 3 IntroductionThe building sector is faced with the gradual exhaustion of natural resources and/or increasing difficulty in accessing them. 27°C, the reaction of alkali-activated GGBS-FA blend paste is dominated by the GGBS activation (dissolution and precipitation of C-A-S-H) while at 60°C the reaction is due to combined interaction of FA and GGBS, which indicates that FA has lower reactivity than GGBS under ambient conditions. There is only small interaction of fly ash and GGBS probably due to different kinetics of dissolution process and distribution of species. Puligulla et al.[39] studied GGBS-FA blend pastes. They found that the calcium that dissolves from slag significantly influences both early and late age properties. The availability of free Ca ions seems to prolong FA dissolution and enhance geopolymer gel formation. It is proposed that the hardening process is initiated by the precipitation of C-A-S-H and that rapid hardening continues due to accelerated geopolymerization. Liu et al. 5The studies mentioned above reveal that, under particular conditions, mixing two different precursors cangive very interesting results. However, these studies have usually focused on the identification of a particular property under particu...

show abstract

Section: Sample Production and Characterizationsupporting

confidence: 92%

Section: Introductionmentioning

confidence: 99%

Formulation and characterization of blended alkali-activated materials based on flash-calcined metakaolin, fly ash and GGBS

Samson

Cyr

Gao

2017

Construction and Building Materials

View full text Add to dashboard Cite

show abstract

“…When the alkali activator contains soluble silicate, the calcium dissolved from the fly ash is able to form precipitates in the liquid phase, rather than on the fly ash surface, thus reducing hindrance of the dissolution of bulk particles [24]. The much higher reaction heat release rate for fly ash-based geopolymer mixes containing higher CaO or slag contents has been demonstrated [21,25]. However, in the case of manufacturing GFC, slag substitution also changes the pore structure, due to the changes in rheology and setting time.…”

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

463

160

View full text Add to dashboard Cite

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.

show abstract

“…It is formed by using source materials containing reactive silica (SiO 2 ) and alumina (Al 2 O 3 ) activated with alkali solutions. The source of materials can be obtained abundantly, such as fly ash (FA), calcined clay, metakaolin or granulated blast furnace slag (GBFS) [1,2]. Researches on geopolymers mostly were application of class F fly ash mixed with activator alkali to produce high strength geopolymer paste [4].…”

Section: Introductionmentioning

confidence: 99%

The Effect of Temperature Curing on Geopolymer Concrete

Ekaputri¹,

Priyanka²

2017

MATEC Web Conf.

View full text Add to dashboard Cite

.This study presents curing temperature influences to behaviors of geopolymer concrete. The concrete was fly ash based, with the ratio of fly ash to alkaline activator was 65%:35%. Ratio coarse aggregate to fine aggregate was 60%:40%, ratios Na 2 SiO 3 /NaOH were 1.5:2 and 2.5. A polycarboxilate superplasticizer with ratio was 2% to fly ash weight. Form of the test specimens were cylinder with diameter of 10 cm and 20 cm high. Steam curing conducted were at 40ᴼC, 60ᴼC and 80ᴼC for 24 hours. The control specimens were treated at normal moist curing. Tests conducted were compressive strength, tensile strength, porosity and elasticity modulus. The results indicated that at the elevated temperature the compressive strength increases as well as tensile strength but decreases the closed porosity of specimens. The elasticity modulus had a similar tendency.

show abstract

Influence of granulated blast furnace slag on the reaction, structure and properties of fly ash based geopolymer

Cited by 657 publications

References 37 publications

Formulation and characterization of blended alkali-activated materials based on flash-calcined metakaolin, fly ash and GGBS

Formulation and characterization of blended alkali-activated materials based on flash-calcined metakaolin, fly ash and GGBS

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

The Effect of Temperature Curing on Geopolymer Concrete

Contact Info

Product

Resources

About