scholarly journals A study of alkali-activated concrete mixes with ground granulated blast furnace slag

2018 ◽  
Vol 20 (2) ◽  
pp. 208-215
Keyword(s):  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Statistical Significance ◽  
Alkali Activation ◽  
Curing Conditions ◽  
Granulated Blast Furnace Slag ◽  
Number Of Factors ◽  
Furnace Slag ◽  
Alkali Activated Concrete ◽  
Alkali Activated

The paper presents a laboratory study of concrete mixes based on the alkali-activation of an industrial by-product, ground granulated blast furnace slag (GGBS). A number of factors potentially affecting the resulting concrete quality in terms of workability and strengths were investigated (namely activator type, molarity, curing conditions and times). The statistical significance of the effect of these factors was supported by ANOVA. Higher workability and strengths (with lower activator concentrations) were obtained for KOH containing mixes. Curing at constant moisture and ambient temperature was successful for most alkaline activators and mixes, which showed good concrete strengths at all curing times; when Na2SiO3 was used in addition to NaOH or KOH activators of moderate to high molarity, strengths exceeded those of Ordinary Portland Cement (CEM-I) concrete of a similar water/cement ratio.

Comparison of Selected Properties of Portland Cement Based Materials and Alkali Activated Materials Based on Granulated Blast Furnace Slag

2016 ◽  
Vol 865 ◽  
pp. 107-113 ◽  
Author(s):  
Pavel Mec ◽  
Jana Boháčová ◽  
Josef Koňařík
Keyword(s):  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Water Glass ◽  
Sodium Metasilicate ◽  
Alkali Activation ◽  
Granulated Blast Furnace Slag ◽  
Cement Based Materials ◽  
One Year ◽  
Furnace Slag ◽  
Alkali Activated

Alkali activated systems are materials formed by alkali-activation of latent hydraulic or pozzolanic materials. The outcome is a polymeric structure with properties comparable to materials based on cement.The principle of the experiment is to compare selected properties of alkali-activated materials based on blast furnace slag and using various types of activator (sodium water glass, potassium water glass, DESIL AL and sodium metasilicate) to binders based on white and Portland cements of the highest quality. The samples were left for one year in environments simulating the conditions in the interior and exterior. Selected physical-mechanical properties were evaluated and compared.

Experimental Study on Compound Binding Material of Alkali Activated Metakaolin and Ground Granulated Blast Furnace Slag

2011 ◽  
Vol 287-290 ◽  
pp. 1275-1279
Author(s):  
Yong Jia He ◽  
Lin Nu Lu ◽  
Shu Guang Hu
Keyword(s):  
Compressive Strength ◽  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Hydration Product ◽  
Alkali Activation ◽  
Granulated Blast Furnace Slag ◽  
Binding Material ◽  
Measurement Results ◽  
Furnace Slag ◽  
Alkali Activated

Compound binding material was prepared by the alkali activation of metakaolin and ground granulated blast furnace slag. Hydration product components, microstructure and mechanical properties of the hardened paste were investigated by IR, XRD, SEM, MIP, and compressive strength measurement. Results indicated that hydration products included C-S-H and geopolymer, and both of them were amorphous although there were differences in their structure and morphology. When the dosage of slag was less than 50%, the compressive strength of hardened paste increased as the dosage increased, which was mainly because C-S-H produced by the reaction of GGBFS and alkali filled void in geopolymer phase, and part of unreacted slag particles acting as microaggregate to prevent from extension of microcrack in the hardened paste, so the porosity of hardened paste decreased and compressive strength increased.

scholarly journals Optimizing Precursors and Reagents for the Development of Alkali-Activated Binders in Ambient Curing Conditions

2021 ◽  
Vol 5 (2) ◽  
pp. 59
Author(s):  
Dhruv Sood ◽  
Khandaker M. Anwar Hossain
Keyword(s):  
Blast Furnace ◽  
Fly Ash ◽  
Blast Furnace Slag ◽  
Curing Conditions ◽  
Granulated Blast Furnace Slag ◽  
Hardened State ◽  
Alkali Activated Binders ◽  
Furnace Slag ◽  
Alkali Activated ◽  
Ambient Curing

Alkali-activated binders (AABs) are developed through the activation of aluminosilicate-rich materials using alkaline reagents. The characteristics of AABs developed using a novel dry-mixing technique incorporating powder-based reagents/activators are extensively explored. A total of forty-four binder mixes are assessed in terms of their fresh and hardened state properties. The influence of mono/binary/ternary combinations of supplementary cementitious materials (SCMs)/precursors and different types/combinations/dosages of powder-based reagents on the strength and workability properties of different binder mixes are assessed to determine the optimum composition of precursors and the reagents. The binary (55% fly ash class C and 45% ground granulated blast furnace slag) and ternary (25% fly ash class C, 35% fly ash class F and 40% ground granulated blast furnace slag) binders with reagent-2 (calcium hydroxide and sodium sulfate = 2.5:1) exhibited desired workability and 28-day compressive strengths of 56 and 52 MPa, respectively. Microstructural analyses (in terms of SEM/EDS and XRD) revealed the formation of additional calcium aluminosilicate hydrate with sodium or mixed Ca/Na compounds in binary and ternary binders incorporating reagent-2, resulting in higher compressive strength. This research confirms the potential of producing powder-based cement-free green AABs incorporating binary/ternary combinations of SCMs having the desired fresh and hardened state properties under ambient curing conditions.

Hybrid Alkali Activated Concretes - Conception and Development for Practical Application

2016 ◽  
Vol 249 ◽  
pp. 3-7 ◽  
Author(s):  
Vlastimil Bílek ◽  
Jan Hurta ◽  
Petra Done ◽  
Libor Zidek ◽  
Tomas Zajdlik
Keyword(s):  
Blast Furnace ◽  
Fly Ash ◽  
Blast Furnace Slag ◽  
Mineral Admixtures ◽  
Alkali Activation ◽  
Granulated Blast Furnace Slag ◽  
Mineral Additions ◽  
New Type ◽  
Furnace Slag ◽  
Alkali Activated

Hybrid cements represent a relatively new type of binders which combine some of the advantages of Ordinary Portland Cement (OPC), the application of mineral admixtures and alkali activation. Hybrid cements represent blends containing a low portion of OPC and a high proportion of mineral additions (such as blast furnace slag, fly ash, metakaolin ....). The paper is focused on the study of properties of mortars prepared from hybrid cements. Mortars with hybrid cements were prepared for an evaluation of the effects of the dosage and the composition of alkali activator, the dosage of OPC and the ratio between ground granulated blast furnace slag and fly ash. The results make it possible to optimize the composition of hybrid alkali activated concretes.

Synthesis and characterization of new inorganic polymeric composites based on kaolin or white clay and on ground-granulated blast furnace slag

2003 ◽  
Vol 18 (11) ◽  
pp. 2571-2579 ◽  
Author(s):  
I. Lecomte ◽  
M. Liégeois ◽  
A. Rulmont ◽  
R. Cloots ◽  
F. Maseri
Keyword(s):  
Blast Furnace ◽  
Vickers Hardness ◽  
Blast Furnace Slag ◽  
Polymeric Materials ◽  
Magic Angle Spinning ◽  
Alkali Activation ◽  
Magic Angle ◽  
Scanning Calorimetry ◽  
Granulated Blast Furnace Slag ◽  
Furnace Slag

Alkali activation of dehydroxylated kaolin or clay yielded high-strength polymeric materials, so-called geopolymers. They were synthesized by mixing the aluminosilicate with solutions of sodium metasilicate and KOH followed by adding 45 wt.% of ground-granulated blast furnace slag. The influence of the aluminosilicate source, its activation temperature, and the order of mixing raw materials were studied on the workability of the blending paste, the microstructure, and the Vickers hardness of the geopolymer samples. The polymeric material is completely amorphous according to x-ray diffraction. Solid-state 27Al and 29Si magic-angle-spinning nuclear magnetic resonance showed that the geopolymer consists of AlO4 and SiO4 tetrahedra linked together through a polymeric network constituted by branched entities SiQ4(4Al) and SiQ4(3Al), but also by less-polymerized silicates SiQ1 and SiQ2. Scanning electron microscopy showed a homogeneous polymeric gel matrix containing unreacted slag (and quartz) grains; thermogravimetric analysis and differential scanning calorimetry exhibited a high content of water and an elevated melting point (1260°C). Vickers hardness values are in the range of 200 MPa.

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