Experimental Explanation of Compacting Effect on Hydration Phases and Strength Development Mechanism Derived From Pozzolanic Reaction of Fly Ash

Yamamoto, Takakazu; Kanazu, Tsutomu

doi:10.2208/jsceje.63.52

Cited by 13 publications

(5 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The glass ratio is the content excluding crystalline oxides and SO 3 , assuming that all of the materials are oxides. The mullite ratio and glass ratio are more than 50 wt % in these samples, similar to the results in previous studies . However, it was difficult to obtain the exact true density because a large part of the materials was amorphous.…”

Section: Resultssupporting

confidence: 88%

Factors Affecting the Density and Specific Surface Area (Blaine Value) of Fly Ash from Pulverized Coal Combustion

2011

View full text Add to dashboard Cite

In the Japanese electric power industry, it is desirable to reduce the cost of treatment and expand the range of use of fly ash, such as in concrete admixtures. Therefore, it is necessary to form high-quality fly ash. To obtain high-quality fly ash, it is important to clarify the factors affecting its properties. In this study, the factors affecting the density and specific surface area (Blaine value) of coal fly ash were investigated on the basis of experimental results obtained using our combustion test facility and the ash data from the boiler of an actual electric power plant. The density was affected by the ash particle size, the true density of the component materials, and the aluminum content, which is closely related to the fusibility. The specific surface area was affected by the particle size distribution and particle shape. The shape was affected by not only the ash particle size but also the unburned carbon concentration and the ash fusibility. It was also found that the specific surface area of the ash generated from our combustion test facility is higher than that of ash from the actual boiler for ash with the same particle size. This result indicates that the shape of particles is affected by their heating and formation histories in the boiler. On the basis of the above findings, correlation equations were obtained for the density and Blaine value.

show abstract

Section: Resultssupporting

confidence: 88%

Factors Affecting the Density and Specific Surface Area (Blaine Value) of Fly Ash from Pulverized Coal Combustion

2011

View full text Add to dashboard Cite

show abstract

“…It can be explained by the fact that the use of 20% replacement of fly ash at the same water to binder ratio increased the water to cement ratio; resulting in promoting the hydration extent of cement and fly ash which forms more hydration products filling up the pores of the paste [5,13]. Furthermore, the decreasing and increasing tendency of the volume ratio of pores ranging 20-330 nm and 3-20 nm in diameter relative to the total pores respectively are also reported when the pozzolanic reaction of fly ash occurs [19]. These tendencies are also observed in the cases of FA20 and FA40 when compared with FA0.…”

Section: Porositymentioning

confidence: 87%

A study on pozzolanic reaction of fly ash cement paste activated by an injection of alkali solution

Bùi

Ogawa

Nakarai

et al. 2015

Construction and Building Materials

View full text Add to dashboard Cite

“…According to Yamamoto and Kanazu [30], the volume of pores in the 0.02-0.33 lm range decreased and that of pores in the 0.003-0.02 lm range increased as the pozzolanic reaction of fly ash proceeded. The volumes of these pore ranges are also shown in Fig.…”

Section: Volume Of Pores Related To Pozzolanic Reactionmentioning

confidence: 98%

Long-term pozzolanic reaction of fly ash in hardened cement-based paste internally activated by natural injection of saturated Ca(OH)2 solution

2018

View full text Add to dashboard Cite

The pozzolanic reaction of fly ash in hardened cement-based paste internally activated by a natural injection of saturated Ca(OH) 2 solution from the age of 1 month was investigated. This investigation was conducted with the aim of comprehensively evaluating the long-term effectiveness of this technique. The Ca(OH) 2 content, degree of the fly-ash reaction, and pore structure were measured using thermal gravimetric analysis, selective dissolution, and mercury intrusion porosimetry, respectively. The Ca(OH) 2 consumption was calculated from the Ca(OH) 2 content in the pastes with 0 and 40% replacements of cement by fly ash. The cement hydration and pozzolanic reactions of fly ash in the pastes proceeded gradually up to 12 months, but were negligible from 12 to 24 months regardless of whether solution was injected. An injection of alkali solution increased both the Ca(OH) 2 consumption and the degree of the fly-ash reaction after aging for 12 months. The relationship between the Ca(OH) 2 consumption and degree of the fly-ash reaction indicated that the injection of alkali solution activated the surface of the fly-ash particles at early ages, whereas the injection of water did not activate these particles but accelerated the cement hydration, which promoted the pozzolanic reaction. The refinement of the pore structure in the pastes confirmed the effectiveness of the solution injection. Consequently, the injection of saturated Ca(OH) 2 solution from the age of 1 month directly activated fly-ash particles and accelerated the long-term pozzolanic reaction (i.e., up to 24 months) in hardened cement paste with 40% replacement by fly ash, although it was not effective in further enhancing the pozzolanic reaction from 12 to 24 months. Keywords Internal alkali activation Á Ca(OH) 2 content Á Degree of fly-ash reaction Á Pore structure Á Selective dissolution The original version of this article was revised due to a retrospective Open Access order.

show abstract

Experimental Explanation of Compacting Effect on Hydration Phases and Strength Development Mechanism Derived From Pozzolanic Reaction of Fly Ash

Cited by 13 publications

References 10 publications

Factors Affecting the Density and Specific Surface Area (Blaine Value) of Fly Ash from Pulverized Coal Combustion

Factors Affecting the Density and Specific Surface Area (Blaine Value) of Fly Ash from Pulverized Coal Combustion

A study on pozzolanic reaction of fly ash cement paste activated by an injection of alkali solution

Long-term pozzolanic reaction of fly ash in hardened cement-based paste internally activated by natural injection of saturated Ca(OH)2 solution

Contact Info

Product

Resources

About