The importance of the network modifying element content in fly ash

Although the amorphous phase content has been considered one of the important factors governing the strength development of alkali activated fly ashes [10] [12] this result suggests that the network modifying element content may be a more accurate measure for assessing the alkali activation of fly ash than the amorphous content in terms of

Behaviour of alkali activated fly ash slag paste at elevated

Alkali activated fly ash slag AAFS Meanwhile the content of unreacted fly ash and slag particles declined from roughly 30 % to less than 5 % with the increase of temperature from 20 to 800 °C After image processing phase assemblage in AAFS paste at elevated temperatures can be summarised Fig 7 At all temperature levels reaction

Mix proportion design and carbon emission assessment of

The results indicate that the optimal mix proportion for HSGPC includes 15% fly ash content % silica fume content alkali activator ratio of and a NaOH molar concentration of 10 M

Solidification of municipal solid waste incineration fly ash

Incineration technology is the most mainstream disposal method of municipal solid wastes Tapan 2009; Luo et al 2019 The resulting municipal solid waste incineration fly ash MSWIFA is g enerated with vast quantities and its output has increased with each passing day Liu et al 2020 According to statistics the generation of MSWIFA has reached

Fly ash based artificial aggregates synthesized through alkali

The shortage of natural aggregates caused by massive infrastructure construction has promoted the development of alternative aggregates In this study artificial aggregates based on alkali activated technology were designed and manufactured where fly ash FA and a blended sodium silicate/hydroxide solution were used as the precursor and

Mechanical and durability properties of alkali activated fly ash

The alkali activation of fly ash and slag individually as single precursors each have specific challenges Alkali activated fly ash usually requires curing at elevated temperatures to develop strength which is a potential barrier to widespread use in the concrete industry [17]

Hydration mechanism of red mud fly ash based geopolymer

The content of the aluminosilicate component is low and the activity is lower than of fly ash Consequently the mechanical strength of RFG decreases as the red mud dosage is increased Furthermore Fig 3 a reveals that the mechanical strength of RFG decreased slightly when the dosage of red mud was lower than 30 wt%

A review Reaction mechanism and strength of slag and fly ash

A review Reaction mechanism and strength of slag and fly ash based alkali activated materials Author links open overlay panel Beibei Sun a Guang Ye b Geert de Schutter a Show more Add to Mendeley While for alkali solution with low Na 2 O content increasing the l/b ratio may greatly reduce the strength Therefore using the parameter

Influence of Different Parameters on the Performance of Alkali

The effects of four parameters of fly ash content water glass modulus water glass solid content and water solid ratio on the working performance and mechanical properties of alkali activated slag fly ash composite cementation system were discussed The gelling system was studied by microscopic experiments such as SEM and FTIR

Multiscale micromechanical analysis of alkali activated fly ash

Current demand for highly sustainable concrete alkali activated fly ash slag AAFS concrete urges understanding the links between microstructure and micromechanical properties of this binder Nevertheless more cross linked binders with durable solid microstructure can be obtained in the mixture with a high fly ash content

Quantitative determination of phases in the alkali activation of fly

The alkali activation of fly ash AAFA is a distinctive procedure in which this grey powder FA is mixed with alkaline activators alkaline solutions and then cured at a certain temperature to produce a solid material [10] showed that the vitreous phase content of a fly ash is one of the factors determining its reactivity in alkaline

Leaching kinetics and reactivity evaluation of fly ash based

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

Influence of the Fly Ash Content on the Fresh and Hardened

The setting time of the 100% BFS sample was an initial time of h and a final time of h while those of the other samples were delayed 10 h and h for 85% BFS and 19 h and h for 70% BFS A higher proportion of fly ash in the alkali activated slag/fly ash mixtures led to a slower setting due to the lower reactivity of the ash

Effects of alkaline activated fly ash and Portland cement on

This paper studies the effects of sodium based alkaline activators and class F fly ash on soil stabilisation Using the unconfined compressive strength test UCS the effectiveness of this binder is compared with that of a common cement based binder Influence of the activator/ash ratio sodium oxide/ash ratio and sodium hydroxide concentration was also

Microstructure strength development mechanism and CO2

In alkali activated fly ash the dominant gel is N A S H whereas alkali activated slag exhibits a structure primarily dominated by C A S H gel The effects of ground granulated blast furnace slag blending with fly ash and activator content on the workability and strength properties of geopolymer concrete cured at ambient

Leaching kinetics and reactivity evaluation of fly ash based

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

Mechanical properties and durability of alkali activated fly ash

Secondly high fly ash content or alkali equivalent rendered concrete porous and loose In the early stages it could absorb more water to improve the quality of concrete The interior fissures in concrete progressively grew deeper with the increase of freeze thaw cycles and the mortar in the hole crumbled away causing a greater relative mass

Chloride binding mechanism and free chloride reduction method of alkali

The chloride binding mechanism of alkali activated materials AAM under various granulated blast furnace slag GBFS /fly ash FA ratios is investigated in this work Two types of layered double hydroxides LDH MgAl LDH and CaAl LDH and active magnesium oxide MgO were added to reduce the concentration of free chloride in AAM

Assessing the effect of fly ash with a high SO3 content in

Hybrid alkaline fly ash pastes HAFAPs are a new generation of alkaline activated binders that use low amounts of Portland cement and high amounts of fly ash FA fact that the exposure condition is extremely significant in the deterioration of the HAFAPs fabricated with high SO 3 fly ash content Potentially fly ash that contains high

Utilization of municipal solid waste incinerator fly ash under

MSW incineration creates a variety of residual products notably bottom ash and fly ash which make up approximately 90 % and 5 % of all combustion leftovers respectively [5] Currently bottom ash is being repurposed in the reclamation of metals and the production of construction materials [6] Nevertheless fly ash which contains organic components high in

Mechanical properties and durability of alkali activated fly ash

Secondly high fly ash content or alkali equivalent rendered concrete porous and loose In the early stages it could absorb more water to improve the quality of concrete The interior fissures in concrete progressively grew deeper with the increase of freeze thaw cycles and the mortar in the hole crumbled away causing a greater relative mass

Multiscale micromechanical analysis of alkali activated fly ash

Current demand for highly sustainable concrete alkali activated fly ash slag AAFS concrete urges understanding the links between microstructure and micromechanical properties of this binder Nevertheless more cross linked binders with durable solid microstructure can be obtained in the mixture with a high fly ash content

Synthesis of alkali activated materials blended with fly ash

In contrast olive pomace fly ash exhibits a substantial silica content % a moderate quantity of aluminum % with notable occurrences of sodium % potassium % and calcium % due to the high calcium content present in olive pomace fly ash the term alkali activated materials is used in this study

Mechanical properties and microstructure evolution of 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