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 Influence of Pb Dosage on Immobilization Characteristics of Different Types of Alkali-Activated Mixtures and Mortars

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Jan Koplík ◽  
Jaromír Pořízka ◽  
Lukáš Kalina ◽  
Jiří Másilko ◽  
Matěj Březina
Keyword(s):  
Mechanical Properties ◽  
Heavy Metals ◽  
Heavy Metal ◽  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Inductively Coupled Plasma ◽  
Raw Materials ◽  
Leaching Tests ◽  
Furnace Slag ◽  
Alkali Activated

Alkali-activated matrices are suitable materials for the immobilization of hazardous materials such as heavy metals. This paper is focused on the comparison of immobilization characteristics of various inorganic composite materials based on blast furnace slag and on the influence of various dosages of the heavy metal Pb on the mechanical properties and fixation ability of prepared matrices. Blast furnace slag (BFS), fly ash, and standard sand were used as raw materials, and sodium water glass was used as an alkaline activator. Pb(NO3)2served as a source of heavy metal and was added in various dosages in solid state or as aqueous solution. The immobilization characteristics were determined by leaching tests, and the content of Pb in the eluate was measured by inductively coupled plasma optical emission spectroscopy (ICP-OES). The microstructure of matrices and distribution of Pb within the matrix were determined by scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDS). Increasing the dosage of the heavy metal had negative impacts on the mechanical properties of prepared matrices. The leaching tests confirmed the ability of alkali-activated materials to immobilize heavy metals. With increasing addition of Pb, its content in eluates increased.

Mechanical properties of alkali activated blast furnace slag pastes reinforced with carbon fibers

2016 ◽  
Vol 116 ◽  
pp. 63-71 ◽  
Author(s):  
J.L. Vilaplana ◽  
F.J. Baeza ◽  
O. Galao ◽  
E.G. Alcocel ◽  
E. Zornoza ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Blast Furnace ◽  
Carbon Fibers ◽  
Blast Furnace Slag ◽  
Furnace Slag ◽  
Alkali Activated

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.

The Leachability of Heavy Metals from Alkali-Activated Fly Ash and Blast Furnace Slag Matrices

2016 ◽  
Vol 851 ◽  
pp. 141-146
Author(s):  
Jan Koplík ◽  
Miroslava Smolková ◽  
Jakub Tkacz
Keyword(s):  
Mechanical Properties ◽  
Heavy Metals ◽  
Blast Furnace ◽  
Fly Ash ◽  
Blast Furnace Slag ◽  
Inductively Coupled Plasma ◽  
Emission Spectrometry ◽  
Alkali Activation ◽  
Furnace Slag ◽  
Alkali Activated

The ability of alkali-activated materials (AAMs) to fix and immobilize heavy metals was investigated. Two raw materials were used to prepare alkali-activated matrices – high-temperature fly ash and blast furnace slag (BFS). NaOH served as an alkaline activator. Two heavy metals (Mn, Ni) were added in different amounts to find out the influence of dosage of heavy metal on the mechanical properties of the matrices and the leachability. Leachability was measured as concentration of heavy metals in leachates (ČSN EN 12457-4) by inductively coupled plasma/optical emission spectrometry (ICP/OES). Structure of prepared matrices was characterized by scanning electron microscopy (SEM). Increasing of addition of heavy metals led to decrease of mechanical properties of matrices. The leaching tests showed, that both matrices can immobilize Mn and Ni in dosages of 0.1 – 2,5%. Higher dosages caused deterioration of the matrices and increased the leachability. After alkali activation both heavy metals were transformed into the form of insoluble salts.

Possibilities of Using Plasticizers in Alkali-Activated Systems

2016 ◽  
Vol 851 ◽  
pp. 57-62
Author(s):  
Lukáš Kalina ◽  
Miroslava Hajdúchová ◽  
Markéta Langová ◽  
Vojtěch Enev
Keyword(s):  
Mechanical Properties ◽  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Preparation Process ◽  
The Stability ◽  
Activated Slag ◽  
Plasticizing Admixture ◽  
Furnace Slag ◽  
Alkali Activated ◽  
Convenient Dose

The study deals with the preparation process and properties of alkali-activated blast furnace slag with different addition of lignosulphonate plasticizer. The goal of this study is to evaluate the suitability of plasticizer and find the convenient dose of this admixture, which improve the workability and mechanical properties of alkali-activated slag. The stability of plasticizing admixture in alkali environment was studied by infrared spectroscopy (FTIR).

scholarly journals MECHANICAL PROPERTIES OF CEMENT COMPOSITE CONTAINING RECYCLED CONCRETE AND ALKALI ACTIVATED BLAST FURNACE SLAG

2020 ◽  
Vol 26 ◽  
pp. 30-33
Author(s):  
Jan Horych ◽  
Pavel Tesárek ◽  
Zdeněk Prošek
Keyword(s):  
Mechanical Properties ◽  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Cement Composite ◽  
Strength Loss ◽  
Recycled Concrete ◽  
Cement Composites ◽  
Positive Effect ◽  
Furnace Slag ◽  
Alkali Activated

Recycling of materials is very popular and very important in these days. Finding the new ways to process and use these materials is a key to get rid of a lot of construction waste. The amount of landfilling needs to be reduced. This study observes mechanical properties of the cement composites containing recycled concrete powder and alkali-activated blast furnace slag processed on a high- peed mill as a potential binder replacement up to the 60 wt. %. These materials have a positive effect on hydration process, increase flexural strength. It can reduce compressive strength loss when an amount of cement in the mixture is reduced.

scholarly journals Mathematical Modelling to Control the Chemical Composition of Blast Furnace Slag Using Artificial Neural Networks and Empirical Correlation

2021 ◽  
Vol 1203 (3) ◽  
pp. 032096
Author(s):  
Wandercleiton Cardoso ◽  
Danielle Barros ◽  
Raphael Baptista ◽  
Renzo di Felice
Keyword(s):  
Blast Furnace ◽  
Chemical Composition ◽  
Blast Furnace Slag ◽  
Raw Materials ◽  
Raw Material ◽  
Operational Parameters ◽  
Materials Research ◽  
Artificial Neural ◽  
Furnace Slag ◽  
Alkali Activated

Abstract Portland cement additions have been used for many years with the main objective of reducing the amount of clinker. Among the additions, blast furnace slag, resulting from the production of pig iron, that is, reusing this by-product, reduces the emission of carbon dioxide as well as decreases the exploitation of natural limestone and clay reserves, which are raw materials for Portland clinker. In order to reduce these emissions and increase the availability of raw materials, research has been directed to study clinker-free binders, as is the case with activated alkali cements and supersulfated cements. In this way, alkali-activated cements can only involve the reuse of industry by-products and do not require the calcination of the raw material, thus reducing the emission of polluting gases into the atmosphere. Supersulfated cement are composed of up to 90% blast furnace slag, in addition to 10 to 20% calcium sulfate. One of the most important characteristics of blast furnace slag is the ratio of the content of CaO and SiO2, also known as the simplified basicity index (B2). This paper proposes the mathematical modeling of an artificial neural network to predict the final chemical composition of the blast furnace slag to be produced based on the operational parameters of the blast furnace aiming its use in the production of special cements such as alkali-activated cements and supersulfated cements. The high values of (R) associated with low values (RMSE) show the good statistical performance of ANN demonstrating that the mathematical model is efficient to carry out the forecast of the production of blast furnace slag.

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