scholarly journals Optimum Use of Sugar Cane Straw Ash in Alkali-Activated Binders Based on Blast Furnace Slag

2018 ◽  
Vol 30 (6) ◽  
pp. 04018084 ◽  
Author(s):  
João Claudio Bassan de Moraes ◽  
Mauro Mitsuuchi Tashima ◽  
José Luiz Pinheiro Melges ◽  
Jorge Luís Akasaki ◽  
José Monzó ◽  
...  
Keyword(s):  
Blast Furnace ◽  
Sugar Cane ◽  
Blast Furnace Slag ◽  
Alkali Activated Binders ◽  
Furnace Slag ◽  
Alkali Activated ◽  
Straw Ash

scholarly journals Resistance to external sulfate attack - Comparison of two alkali-activated binders

2018 ◽  
Vol 163 ◽  
pp. 06001
Author(s):  
Miroslav Komljenović ◽  
Nataša Džunuzović ◽  
Violeta Nikolić
Keyword(s):  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Sodium Silicate Solution ◽  
Silicate Solution ◽  
Sulfate Attack ◽  
Commercial Application ◽  
Experimental Conditions ◽  
Alkali Activated Binders ◽  
Furnace Slag ◽  
Alkali Activated

Durability of binders, mortars and concretes in aggressive environments is of crucial importance for their commercial application. In this paper the resistance to external sulfate attack of two different alkaliactivated binders (AABs), based either on blast furnace slag (BFS) or fly ash/blast furnace slag (FA/BFS) blend, was compared with two different commercially available Portland cement (CEM II) blended either with BFS or with FA and BFS. Comparison of sulfate resistance was based on compressive strength testing (the loss of strength) of mortar samples exposed to sodium sulfate attack up to 180 days and samples cured under controlled conditions for the same period of time. Furthermore, the evolution of microstructure of alkali-activated binders and pH of sodium silicate solution during testing were also analyzed. Despite different gel chemistry being involved, both alkali-activated binders based either on BFS or FA/BFS blend showed excellent resistance to external sulfate attack and even better than selected Portland cements tested under the same experimental conditions.

scholarly journals Interactions of Various types between Rock and Alkali-Activated Blast Furnace Slag

2017 ◽  
Vol 63 (1) ◽  
pp. 22-26
Author(s):  
Pavel Mec ◽  
Lucie Gembalová
Keyword(s):  
Mechanical Properties ◽  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Ordinary Portland Cement ◽  
Raw Materials ◽  
Matrix Composition ◽  
Cement Binder ◽  
Alkali Activated Binders ◽  
Furnace Slag ◽  
Alkali Activated

Abstract Alkali-activated binders (AAB) are very intensively studied materials nowadays. Because of possible usage as secondary raw materials, they can be environmentally efficient. Intensive research is focused especially on binder matrix, composition and its structure. For industrial usage, it is necessary to work with some aggregate for the preparation of mortars and concretes. Due to different structures of alkali-activated binders, the interaction with the aggregate will be different in comparison to an ordinary Portland cement binder. This paper deals with the study of interactions between several types of rocks used as aggregate and alkali-activated blast furnace slag. The research was focused especially on mechanical properties of prepared mortars.

scholarly journals Alkali-activated binders based on ground granulated blast furnace slag and phosphogypsum

2019 ◽  
Vol 215 ◽  
pp. 371-380 ◽  
Author(s):  
Katrijn Gijbels ◽  
Remus Ion Iacobescu ◽  
Yiannis Pontikes ◽  
Sonja Schreurs ◽  
Wouter Schroeyers
Keyword(s):  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Granulated Blast Furnace Slag ◽  
Alkali Activated Binders ◽  
Furnace Slag ◽  
Alkali Activated

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.

The Influence of the Properties of the Material Used for Obtaining Geopolymers on Their Structure and Compressive Strength

2017 ◽  
Vol 68 (6) ◽  
pp. 1182-1187
Author(s):  
Ilenuta Severin ◽  
Maria Vlad
Keyword(s):  
Compressive Strength ◽  
Blast Furnace ◽  
Wheat Straw ◽  
Red Mud ◽  
Blast Furnace Slag ◽  
Complex Structure ◽  
Point Of View ◽  
Granulated Blast Furnace Slag ◽  
Furnace Slag ◽  
Straw Ash

This article presents the influence of the properties of the materials in the geopolymeric mixture, ground granulated blast furnace slag (GGBFS) + wheat straw ash (WSA) + uncalcined red mud (RMu), and ground granulated blast furnace slag + wheat straw ash + calcined red mud (RMc), over the microstructure and mechanical properties of the synthesised geopolymers. The activation solutions used were a NaOH solution with 8M concentration, and a solution realised from 50%wt NaOH and 50%wt Na2SiO3. The samples were analysed: from the microstructural point of view through SEM microscopy; the chemical composition was determined through EDX analysis; and the compressive strength tests was done for samples tested at 7 and 28 days, respectively. The SEM micrographies of the geopolymers have highlighted a complex structure and an variable compressive strength. Compressive strength varied from 24 MPa in the case of the same recipe obtained from 70% of GGBFS + 25% WSA +5% RMu, alkaline activated with NaOH 8M (7 days testing) to 85 MPa in the case of the recipe but replacing RMu with RMc with calcined red mud, alkaline activated with the 50%wt NaOH and 50%wt Na2SiO3 solution (28 days testing). This variation in the sense of the rise in compressive strength can be attributed to the difference in reactivity of the materials used in the recipes, the curing period, the geopolymers structure, and the presence of a lower or higher rate of pores, as well as the alkalinity and the nature of the activation solutions used.

Degradation of Materials Based on Alkali-Activated Blast-Furnace Slag after Exposure to Aggressive Environments

2021 ◽  
Vol 325 ◽  
pp. 131-136
Author(s):  
Iveta Plšková ◽  
Petr Hrubý ◽  
Libor Topolář ◽  
Michal Matysík
Keyword(s):  
Blast Furnace ◽  
Ammonium Nitrate ◽  
Sodium Sulfate ◽  
Blast Furnace Slag ◽  
Nitrate Solution ◽  
Ammonium Nitrate Solution ◽  
Degradation Of Materials ◽  
Non Destructive ◽  
Furnace Slag ◽  
Alkali Activated

The paper summarizes partial results of a study of degradation of materials based on alkali-activated blast-furnace slag (AAS) and comparative on cement CEM III/A 32.5 R after exposure to aggressive environments. It further specifies the possibilities for utilising destructive and non-destructive techniques to determine the progress of degradation and characterizes the degree of their correlation. After 28 days of ageing in a water environment, the produced test specimens (40×40×160 mm beams) were placed in aggressive media (ammonium nitrate solutions; sodium sulfate, rotating water) and after subsequent 28, 56 and 84 days of degradation were subjected to testing. Testing comprised both a destructive form (determination of compressive strength and flexural strength) and a selected non-destructive technique (Impact-echo method). The partial outputs were supplemented by the results acquired from monitoring weight changes. In addition, the development of Ultrasonic Pulse Velocity in relation to the progress of the degradation processes was also monitored. While the exposure of both test specimens to water and sodium sulfate did not result in any significant changes, the exposure to the ammonium nitrate solution exhibited rapid signs of degradation associated with a significant reduction in functional characteristics.

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