:Publish Year:2021Advances in Geopolymer Materials · This study proposes a strategy, i.e., the combination of sodium carbonate (Nc) and nano-silica (Ns), to comprehensively improve the printability, in particular time
Consulta
Basic Properties of fly Ash/Slag-Concrete Slurry Waste Geopolymer Activated by Sodium Carbonate and Different Silicon Sources Yingli Gao1*, Kairui Duan1, Shuncheng Xiang1 and Wei Zeng2 1School of
Consulta
: Hussam Alghamdi, Narayanan Neithalath · Geopolymer is a new environment-friendly cementitious material, and the development of geopolymer can reduce the carbon dioxide emission caused by the
Consulta
· Effect of sodium carbonate/sodium silicate activator on the rheology, geopolymerization and strength of fly ash/slag geopolymer pastes Cement and Concrete Composites, Volume 97, 2019, pp. 226-238 Ishwarya G ,, S.K. Bhattacharyya
Consulta
· One-part geopolymers were synthesized by calcium carbide reside-sodium carbonate-activation of slag. • Conceptual degradation mechanisms in Na 2 SO 4 and MgSO 4 solutions were proposed. • Ettringite and
Consulta
· In geopolymer technology, silicate solutions are frequently used as alkali activators to dissolve the solid aluminosilicate precursor and aid in binder formation. These corrosive and often viscous solutions are not user-friendly and would be difficult to use for bulk production. Developing geopolymers as a one-part mixture (“just add water”),
Consulta
· Strength decrease may be due to the excess of Na + ions leading to the formation of sodium carbonate. Effect of composition of activating solution on geopolymerization has been studied in detail. The activating solution modulus SiO 2 /Na 2 O and H 2 O/Na 2 O are the main parameters in determining the stoichiometry and the
Consulta
· To manufacture this caustic soda, one uses Egyptian natron (sodium carbonate) and lime (coming from plant ashes) (see chemical formula 1). The so obtained caustic soda, NaOH, will react with clay. The most interesting point is that this chemical reaction creates also pure limestone (calcite) as well as hydrosodalite (a mineral of the
Consulta
In this study, strain-hardening ultra-high-performance geopolymer concrete (SH-UHPGC) was produced using Na2CO3, Na2SiO3 and their hybridization (1:1 in mole ratio) as alkaline activators. An ultra-high compressive strength was achieved for all the developed strain-hardening ultra-high-performance geopolymer concrete (i.e., over 130 MPa). Strain
Consulta
· One of the potential raw materials for preparation of geopolymers is the natural zeolite. In the present report, the used natural zeolite (clinoptilolite) is from huge deposit near Beli Plast, Bulgaria. Geopolymer pastes and mortars are prepared by using three different alkaline activators—sodium hydroxide, sodium silicate and sodium
Consulta
· However the presence of carbonates into the matrices of geopolymers was inversely proportional to the concentration of the initial NaOH. The higher the concentration of initial sodium silicate, the lower the carbonate concentration into the final geopolymerFig. 12).
Consulta
· However appropriate chemical geopolymer process conducted to a clear decrease of carbonate with the increase of the soluble silica from standard sodium silicate. Evidently from the intrinsic characteristics of the silicate solution with more fine particles prompt to react in solution with respect to the silica from RHA-NaOH which the delay
Consulta
· The most investigated activator is sodium hydroxide and sodium silicate, although sodium carbonate seems promising in some research (Feng et al., 2012; Peng et al., 2014, 2017). Sodium carbonate will release carbon dioxide if the high temperature is applied in the calcination process ( Luukkonen et al., 2018 ).
Consulta
Among them, sodium hydroxide (NaOH) and sodium silicate (Na 2 SiO 3) are extensively deployed in geopolymer associated studies due to their excellent performance with
Consulta
· The use of sodium carbonate as an alkali activator in geopolymer binder is often associated with long setting times [[23], [24], [25]]. The setting time was observed to be shortened after the addition of silica fume between 2% and 10% by binder weight as compared to the control paste with no silica fume.
Consulta
In this study, strain-hardening ultra-high-performance geopolymer concrete (SH-UHPGC) was produced using Na2CO3, Na2SiO3 and their hybridization (1:1 in mole ratio) as
Consulta
· Calcium derived from the slag modifies sodium aluminosilicate (N-A-S-H) gel, partially replacing sodium ion with calcium ion to form (Ca,Na)-A-S-H gels which cause rapid hardening in the fly ash-based geopolymer at room temperature [10].
Consulta
· In solid form, sodium metasilicate (Na 2 SiO 3), sodium carbonate (Na 2 CO 3), and potassium hydroxide (KOH) are the major activators used. In that spirit, the sodium-based alkali-activators are generally more available at lower costs with high reactivity, while potassium-based activators have been numerously entertained for high
Consulta
DOI: 10.3389/fmats.2023.1142237 Corpus ID: 256599655 Utilization of sodium carbonate activator in strain-hardening ultra-high-performance geopolymer concrete (SH-UHPGC) Recent research has shown that the incorporation of fibres, such as steel and
Consulta
· However, potassium hydroxide (KOH) or sodium hydroxide (NaOH) as alkali activator solutions, sodium silicate (Na 2 SiO 3), O–C–O stretching asymmetric band was observed at 1450 cm −1, suggesting the presence of
Consulta
· This study proposes a strategy, i.e., the combination of sodium carbonate (Nc) and nano-silica (Ns), to comprehensively improve the printability, in particular time window for printing, and hardened properties of 3D-printing geopolymer concrete (3DPGC).
Consulta
· In porous geopolymers, high porosity values are one of the problems for rapid efflorescence [25], as the structure is opened and sodium is easily carried to the surface as hydrated sodium carbonate. In conclusion, the geopolymer pore structure is one of the most important factors that control the efflorescence rate [22] .
Consulta
As a kind of granular waste with complex composition and alkali corrosiveness, concrete slurry waste (CSW) has severe recycling limitations in the ordinary Portland cement (OPC). Considering this, a new type of geopolymer, prepared by granulated blast furnace slag/fly ash, concrete slurry waste, and powdered activators (sodium carbonate and different
Consulta
· The hardened geopolymer consisting of three paste materials (blast furnace slag, hydroxide solution and sodium silicate) is shown with the letter G in Fig. 13. The number of main cracks in the N80K20 design sample is between 40 and 90 microns, and in the fractured N design sample, the amount of main cracks in Fig. 7 is at least 100
Consulta
· One-part geopolymers were produced from rice husk ash (RHA) by mixing the RHA with solid sodium aluminate at a ratio to yield SiO 2 /Al 2 O 3 = 3.5 and subsequently mixing the solid blend with water and curing at 80 °C and 80% r.H. The compressive strength of the geopolymer was ∼30 MPa after one day of curing.
Consulta
· Firstly, sodium hydroxide reacts with calcium carbonate to produce calcium hydroxide and sodium carbonate and pirssonite Eqs. (1) , (2) and secondly, the remaining calcium carbonate from the reaction acts as a filler material which decreases porosity and increases the compressive strength of activated slag [29] , [30] .
Consulta
The aqueous dissolution of sodium carbonate supplies NaOH which provides the alkaline medium for fly ash geopolymerization (along with externally supplied sodium silicate also, if needed). The CO2 released from the low temperature (∼100 °C) decomposition of carbonates formed as reaction products, acts as the pore-forming agent.
Consulta
This cement hardens rapidly at room temperature and provides compressive strength in the range of 20 MPa, after only 4 hours at 20 C, when tested in accordance with the standards applied to hydraulic binder mortars. The final 28-day compressive strength is in the range of 70-100 MPa, (see Figure 6).
Consulta
· The present study is aimed at advancing the knowledge of the reaction properties and mechanisms of AACs based on sodium carbonate (Na 2 CO 3) on paste, mortar, and concrete. It focuses on the mechanical and hydration properties of the alkali-activated zeolite/slag (AAZS) system based on Na 2 CO 3 for different paste, mortar, and
Consulta
:Sodium CarbonateGeopolymer ConcreteSH-UHPGCConsidering this, a new type of geopolymer, prepared by granulated blast furnace slag/fly ash, concrete slurry waste, and powdered activators (sodium carbonate and different silicon sources including sodium
Consulta
Trituradora de piedra vendida por proveedores certificados, como trituradoras de mandíbula/cono/impacto/móvil, etc.
OBTENER COTIZACIÓN