Effect of content and particle size distribution of high-calcium fly ash on the rheological properties of cement pastes

1997 ◽  
Vol 27 (6) ◽  
pp. 907-916 ◽  
Author(s):  
Stefania Grzeszczyk ◽  
Grzegorz Lipowski
2018 ◽  
Vol 20 (2) ◽  
pp. 51
Author(s):  
Antoni . ◽  
Hendra Surya Wibawa ◽  
Djwantoro Hardjito

This study evaluates the effect of particle size distribution (PSD) of high calcium fly ash on high volume fly ash (HVFA) mortar characteristics. Four PSD variations of high calcium fly ash used were: unclassified fly ash and fly ash passing sieve No. 200, No. 325 and No. 400, respectively. The fly ash replacement ratio of the cementitious material ranged between 50-70%. The results show that with smaller fly ash particles size and higher levels of fly ash replacement, the workability of the mixture was increased with longer setting time. There was an increase in mortar compressive strength with finer fly ash particle size, compared to those with unclassified ones, with the highest strength was found at those with fly ash passing mesh No. 325. The increase was found due to better compactability of the mixture. Higher fly ash replacement reduced the mortar’s compressive strength, however, the rate was reduced when finer fly ash particles was used.


2014 ◽  
Vol 1000 ◽  
pp. 39-42
Author(s):  
Martin Boháč ◽  
Tomáš Opravil ◽  
Eva Bartoníčková ◽  
Františka Frajkorová ◽  
Martin Palou

Viscoelastic properties of Portland cement-metakaolin fresh pastes were measured using rotational rheometer. In mixtures 10 % of Portland cement was replaced by various fractions of metakaolin with different particle size distribution. The role of the fineness of metakaolin was revealed characterizing flow, adhesion and creep of the fresh pastes.


2021 ◽  
Vol 15 (1) ◽  
pp. 75-82
Author(s):  
Mingzi Xu ◽  
Changdong Sheng

The present work aims to develop a simple model for describing the particle size distribution (PSD) of residual fly ash from pulverized biomass combustion. The residual ash formation was modelled considering the mechanism of fragmentation and coalescence. The influences of particle shape and stochastic fragmentation on model description of the PSD of the fly ash were investigated. The results showed that biomass particle shape has a great influence on the model prediction, and a larger fragmentation number is required for cylindrical particles than that for spherical particles to get the same PSD of fly ash, and the fragment number of the particles increases with the shape factor increasing. For pulverized biomass with a wide size distribution, the model predicted ash PSD considering the stochastic fragmentation is very similar to that assuming uniform fragmentation. It implies that the simple model assuming uniform fragmentation is applicable for predicting fly ash size distribution in practical processes where biomass particles have a wide range of sizes. For the fuel with a narrower initial PSD, the stochastic fragmentation model generally predicts a coarser PSD of the residual ash than assuming uniform fragmentation. It means the stochastic fragmentation is of great influence to be considered for accurate description of ash formation from the fuel with a narrow PSD.


2020 ◽  
Vol 11 (11) ◽  
pp. 9547-9559
Author(s):  
Annika Feichtinger ◽  
Elke Scholten ◽  
Guido Sala

Particle size distribution and particle size ratio have an important effect on rheological properties of model chocolate samples, but also other factors like particle shape, surface roughness and hydrophilicity should be taken into account.


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