The preparation process of alkali-activated steel slag cementitious material is shown in Fig. 1.The water-binder ratio used for the test was 0.4. The alkali content was 4% and 6% (mass fraction of Na 2 O to total cementitious material), and the modulus of water glass solution was adjusted to 1.0 by adding NaOH. The prepared alkaline …
This study is focused on alkali-silica reaction (ASR), a chemical process that can cause significant damage to concrete structures. It occurs when alkali hydroxides in the concrete react with ...
In 1923, a number of concrete structures in the USA were observed to develop severe cracking, with unidentified cause. In 1940, Stanton recognized for the first time alkalis, Na and K, in the paste combined with silica from the aggregate, in a deleterious reaction dubbed 'alkali–silica reaction' (ASR) (see [27, entry 1008]).Since its original …
The carbonation reaction of steel slag is a process that utilizes CO 2 to react with calcium and magnesium minerals present in the slag, ... These bacteria are alkali-resistant bacteria, playing a catalytic and leading role in the carbonation process [82], [83]. On one hand, they catalyze carbonation reactions by secreting enzymes, and on …
Alkali activation of metallurgical slags produces low-carbon cementitious binders for sustainable concrete production. However, the potential deleterious reaction of internal alkalis in alkali-activated slag (AAS) with siliceous aggregates is a serious durability concern. In this work, the alkali–silica reaction (ASR) in alkali-activated …
All the alkali metals react vigorously with cold water. In each reaction, hydrogen gas is given off and the metal hydroxide is produced. The speed and violence of the reaction increases as you go ...
Recently, Zhang et al. studied the effect of the w/b ratio on the carbonation of alkali activated slag/fly ash and found that a decrease in the w/b ratio can reduce the formation rate of Ca ...
Song [24] attempts were made to alkali-activate fly ash-steel slag, and it was found that when the substitution rate of steel slag for fly ash was between 20%− 50%, the compressive strength at 28 days decreased significantly with increasing substitution rate. When the substitution rate of steel slag reached 50%, the compressive strength …
The effects of steel slag (SS) and fly ash (FA) on hydration heat, fluidity, setting time and rheological properties of alkali-activated slag (AAS) pastes with different silicate modulus (Ms) values were comparatively investigated. The results show that the incorporation of SS shortens the induction period, increases the cumulative hydration …
In this work, steel slag is utilized for carbon fixation and the obtained carbonated steel slag (CSS) was creatively adopted as solid precursor for the synthesis of alkali-activated materials (AAMs). Physicochemical properties of CSS were fully …
Acids and alkali metals reaction. Alkali metals react with strong acids (HCl, HNO 3, H 2 SO 4) and emit hydrogen gas and produce relevant alkali metal salt. 2Na + 2HCl = 2NaCl + H 2. 2K + H 2 SO 4 = K 2 SO 4 + H 2. Hydrogen and alkali metals reaction. Metal hydrides (H-) are given as products. 2Na + H 2 = 2NaH. Those ionic …
Steel slag (SS) exhibits low hydration activities and expansive phases, which should be pretreated prior to using as binding materials. Thus, these properties of SS …
The AAS and OPC mortars were prepared using a commercial GGBS and an ASTM C150 Type I OPC. The mixtures of AAS were designed with the same 5 % equivalent sodium oxide (Na 2 O) to slag mass, water-to-slag mass ratio of 0.40, and sand-to-paste mass ratio of 1.5, as shown in Table 1.To explore the effect of activator type on …
In the current study, electric arc furnace stainless steel slag (EAFSS) as a potential precursor in the production of alkali activated materials (AAMs) is investigated, …
Alkali-activated materials (AAMs) are favoured for their low carbon emissions, excellent mechanical properties, and excellent chemical resistance. In this paper, ternary alkali-activated cementitious materials were prepared from slag, steel slag, and lithium slag to investigate their strength and resistance to sulphate attack. A series …
In order to compare the properties of alkali-activated carbon steel slag (CSS) and stainless steel slag (SSS), the effects of sodium hydroxide/sodium silicate solution mass ratio (NH/NS), liquid/solid ratio and blast furnace slag (BFS) dosage on the compressive strength, hydration products and hydration degree of CSS and SSS were …
The advantage of steel slag as a calcium-based alkaline material was fully exerted. • Both the low reactivity of tailings and the poor volume stability of steel slag were overcame. • This study provided a new route to improving the comprehensive utilization of tailings and steel slag.
The alkali silica reaction (ASR) is a pathological manifestation of chemical origin and high gravity that can negatively affect the mechanical properties and durability of important concrete structures, even with short time in service. ... the attack of sulfates and corrosion of steel. The effectiveness of slag in the ASR mitigation has been ...
Alkali metals react vigorously to water and air.These elements will dance around, sizzling due to the production of hydrogen gas, and often explode. They get more reactive the further down on the …
Alkali-activated binders refer to any binder material formed through the alkali-induced reaction of silica, alumina, and calcium-containing sources. Geopolymerization is characterized by the chemical reaction between aluminosilicate materials and alkali metal silicates, occurring within highly alkaline environments.
Alkali-activated cement (AAC) is either clinker-less or free, and it is also environmentally friendly due to its low carbon footprint and wide range sources. …
Steelmaking slag carbonation mineralization is an effective method for CO2 in-situ fixation. The rate of steelmaking slag carbonation process could be enhanced by adding alkali medium with low ...
ACR (Alkali-Carbonate Reaction) is a reaction between alkalis in the concrete mortar and the chemical components of carbonate rocks like dolomitic limestones. The reaction causes crystallization and considerable expansion, resulting in substantial damage in a short amount of time.
In the present study, the electric arc furnace carbon or stainless steel slag (EAF) and secondary metallurgical slag such as ladle furnace basic slag (LS) were …
This paper presents results of detailed investigations about the alkaline activation of ground granulated blast furnace slags whose chemical composition were modified. Sodium hydroxide and potassium silicates were used as alkaline activators. The influence of the CaO/SiO2 ratio, the Al2O3 and TiO2 content of the slag composition on …
Ladle slag is commonly regarded as having limited reaction with alkalis, and in previous studies, it has been therefore mixed with reactive precursors, such as …
DOI: 10.1016/j.conbuildmat.2023.134406 Corpus ID: 266063617; Study on the performance and reaction mechanism of alkali-activated clay brick with steel slag and fly ash @article{Liu2024StudyOT, title={Study on the performance and reaction mechanism of alkali-activated clay brick with steel slag and fly ash}, author={YunXiao Liu and Fan …
The HIsmelt smelting reduction process is an efficient direct reduction process for smelting vanadium titanomagnetite ores. About 80% vanadium is enriched in the reduction slag, however, due to the low vanadium and high calcium content in reduction slag, it is difficult to extract the vanadium economically. In this study, a process featuring …
Thus, depending on the type of furnace, steel slag can be broadly classified into three categories, i.e., BOF steel slag, EAF steel slag, and LF steel slag [33]. As for steel slag in alkali ...
Under the influence of alkali activators, such as hydroxides and sodium silicate, alkali-activated materials were prepared by using industrial wastes such as granulated blast furnace slag (GGBS), fly ash (FA), and steel slag (SS), or high-temperature unstable phases rich in silicon-aluminum minerals such as metakaolin and volcanic ash as ...
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نشانی: شماره 1688، جاده شرقی گاوک، منطقه جدید پودونگ، شانگهای، چین.
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