We value your feedback! Please complete the form below so that we can tailor our services to your specific needs.
Geopolymer materials containing fly ash (FA) activated by different NaOH concentrations were studied for study on stabilized soil with saline soil, with NaOH …
WhatsApp: +86 18221755073
Sodium and potassium are the common alkalis present in fly ash. Excessive amounts of fly ash alkalis can cause efflorescence problems in concrete products and raise concern about the effectiveness of the fly ash to mitigate alkali-silica reaction (ASR). The available alkali test, which is commonly used to measure fly ash alkali, takes approximately 35 days for execution and …
WhatsApp: +86 18221755073
Alkalis content in coal fly ash is supposed to be controlled by three variables during the coal burning process and fly ash formation (each at two levels): Factor A: free CaO with …
WhatsApp: +86 18221755073
Alkali-activated fly ash (AAF) exhibits a wider pore size distribution and a slower hydration reaction process at room temperature, which favors ... and seawater. The alkaline content (Na 2 O/binders by mass) of the activator was kept at 6 %, and the modulus was set at 1.2. The liquid-to-solid (L/S) ratio represented the ratio of activator to ...
WhatsApp: +86 18221755073
specification. There are no limits on alkali content of fly ash, but the supplier may report this, expressed as equivalent sodium oxide (Na 2 O). In general, Class F fly ashes are more …
WhatsApp: +86 18221755073
The UCS of the soil increased with the addition of alkali activators, fly ash content, and the curing time. The highest UCS result was found with 25% fly ash content, M+ of 16% and SM of 1.25 at 28 days of curing which can improve the …
WhatsApp: +86 18221755073
Fly ash is a by-product of coal-fired power plants and a rich source of aluminosilicate. This paper reports the compaction and strength properties of fly ash activated …
WhatsApp: +86 18221755073
Then, a long-term durability indicator of concrete could be the coal fly ash alkali content. Such alkali ions are provided by the Portland cement, but also by the coal fly ash when is used as a main cement constituent. In this work, fly ashes from the combustion of a South African coal were investigated. The scope of this paper is to deep in ...
WhatsApp: +86 18221755073
Abstract. The effects of portland cement alkali content, and replacement of portland cement with Class F fly ash, slag, or silica fume on alkali-silica reactivity (ASR) were studied by measuring the expansion of mortar bars made with Pyrex glass and stored over water at 38°C. Expansions were negligible with portland cements having alkali contents of 0.40% Na2O …
WhatsApp: +86 18221755073
contained moderately reactive fine aggregate and high-alkali fly ash from Ottumwa Generating Station (OGS). A total of nine pavement sites were selected to be evaluated. This study investigated the test methods used to determine the alkali content of fly ash. It also evaluated if high-alkali fly ash exacerbates alkali-silica reaction in ...
WhatsApp: +86 18221755073
1. Introduction. Alkali–activated materials (AAMs) or geopolymers are potential sustainable cementitious alternatives to ordinary Portland cement (OPC) [1].AAMs are produced with precursors such as fly ash (FA), ground–granulated blast–furnace slag (GGBFS a.k.a. slag), and metakaolin (MK), and are activated with alkaline activators at room temperature [3], [4], [5].
WhatsApp: +86 18221755073
Sodium and potassium are the common alkalis present in fly ash. Excessive amounts of fly ash alkalis can cause efflorescence problems in concrete products and raise concern about the effectiveness of the fly ash to mitigate alkali-silica reaction (ASR). The available alkali test, which is commonly used to measure fly ash alkali, takes approximately 35 days for execution and …
WhatsApp: +86 18221755073
Sodium and potassium are the common alkalis present in fly ash. Excessive amounts of fly ash alkalis can cause efflorescence problems in concrete products and raise concern about the effectiveness of the fly ash to mitigate alkali-silica reaction (ASR).
WhatsApp: +86 18221755073
The 28-day compressive strength reached 2.16 MPa with a mass concentration of 79.65%, a gangue content of 57.19%, and a fly ash content of 15.67%. Additionally, numerous researchers have studied the mix ratio design of backfill. ... The factors influencing 28-day compressive strength were ranked as fly ash dosage > alkali equivalent > sodium ...
WhatsApp: +86 18221755073
The effect of alkali dosage (A/F), water-binder ratio (w/b), and modulus (Ms) on the performance of fly ash geopolymer (FAG) was reported. The rheology of Na 2 SiO 3 /NaOH …
WhatsApp: +86 18221755073
This study performs a systematic investigation of the effect of SO 3 type and content in fly ash on various performance parameters of cement-fly ash pastes and mortars, including workability (flow and flow retention), pore fluid pH, setting time, strength development, and potential for deleterious expansion. To better quantify and understand ...
WhatsApp: +86 18221755073
In order to efficiently utilize industrial solid waste while minimizing the preparation cost of engineering materials and the technical difficulty of construction, this paper prepared a high fly ash content alkali-activated fly ash slag composite system at normal temperatures and conducted an in-depth investigation on it. A systematic study was conducted on the …
WhatsApp: +86 18221755073
Therefore, the coal fly ash alkali content in blended cements should be as low as possible. The Na2 O-equivalent of coal fly ash in Figure 2 370 Fuels 2022, 3 ranges from 0.35% to 2.53%, with an average value of 0.79%. Despite being the same coal origin, the Na2 O-equivalent results for coal fly ash showed a relatively high degree of dispersion ...
WhatsApp: +86 18221755073
2. Properties and Applications of Fly Ash 2.1. Morphological Properties of Fly Ash. Fly ash is a sphere-shaped, micron-sized (0.01–100 µ) heterogeneous material, having depositions of mainly Al, Si, Fe and C in variable compositions on its surface, and closely resembles the volcanic ashes [].The fly ash particles can be either rough or smooth surfaced …
WhatsApp: +86 18221755073
The optimum alkali-equivalent content in fly ash A was AE% = 7%, with the best compressive strength 38.58 MPa at 20% slag substitution amount. The mix proportion with the second-best compressive strength occurred in fly ash C, at AE% = 8%. The compressive strength was 36.63 MPa when the slag substitution amount was 20%.
WhatsApp: +86 18221755073
Request PDF | On Feb 1, 2023, Wanli Wang and others published Workability, rheology, and geopolymerization of fly ash geopolymer: Role of alkali content, modulus, and water–binder ratio | Find ...
WhatsApp: +86 18221755073
Fly ash content or alkali equivalent increased with a corresponding fall in the relative dynamic elastic modulus of concrete. It could be seen that the relative dynamic elastic modulus of the control group (F0N0) specimen decreased rapidly with the increase of the number of freeze-thaw cycles. When the number of freeze-thaw cycles reached 50 ...
WhatsApp: +86 18221755073
contained moderately reactive fine aggregate and high-alkali fly ash from Ottumwa Generating Station (OGS). A total of nine pavement sites were selected to be evaluated. This study investigated the test methods used to determine the alkali content of fly ash. It also evaluated if high-alkali fly ash exacerbates alkali-silica reaction in ...
WhatsApp: +86 18221755073
The F values of fly ash content and water glass solid content were significantly higher than those of the other two factors. This means that the fly ash content and water glass solid content has a greater impact on the early flexural strength than the other two parameters. 3.4. The Influence of Each Parameter on the Compressive Strength
WhatsApp: +86 18221755073
Fly ash has good pozzolanic activity and contains reactive Al and Si components, it has the potential to dissolve under alkaline conditions to form a dense green gel, i.e. alkali activated binder. But, the widespread implementation of fly ash from different sources in generation of products is constrained by the heterogeneity of raw-material ...
WhatsApp: +86 18221755073
Coal fly ash contains essential constituents for cement production, such as Ca, Si, Al, and Fe. Application of coal-fired ash to produce clinker at high doses may reduce the limestone content in the raw mix.
WhatsApp: +86 18221755073
The recent development of sustainable green cement technology has brought hope on fly ash for production alkali-activated cementitious materials (AACs), due to the high content of SiO 2 and Al 2 O 3 (the sum of SiO 2, Al 2 O 3, and Fe 2 O 3 is approximately 70 %). The practicability of using fly ash to produce AACs has been proven [[24], [25], [26]].Fly ash has …
WhatsApp: +86 18221755073
Fly ash (FA) is the principal industrial waste byproduct from the burning of solid fuels. FA is a powdery solid that is constituted mostly of unburned carbon (UC), metal oxides …
WhatsApp: +86 18221755073
Fly ash is a by-product of coal-fired power plants and a rich source of aluminosilicate. This paper reports the compaction and strength properties of fly ash activated with different concentrations of lime, cement, and alkali solution. The …
WhatsApp: +86 18221755073
The aluminum content in fly ash is primarily found within the glassy phase and various crystalline constituents, including mullite and albite. ... reflecting the reactivity of fly ash in alkali-activation processes, ranges from 4.52 to 24.90 in this work. The R value exhibits high predictive accuracy for estimating the strengths development of ...
WhatsApp: +86 18221755073
