The effect of prolonged mechanical activation duration on the reactivity of Portland cement: Effect of particle size and crystallinity changes

In this paper, low-heat Portland cement (LHC) clinkers were prepared by calcining raw materials at 1350°C for 2.0 hours, 1400°C for 1.0 hour, 1400°C for 1.5 hours, 1400°C for 2.0 hours, 1450°C for 1.0 hour, and 1450°C for 2.0 hours. The clinkers were ground with gypsum to produce LHC. The particle size of periclase was analysed by BSEM. Expansion of LHC pastes due to hydration of periclase was measured. The hydration degree of periclase in LHC pastes was quantitatively determined by XRD internal standard method and BSEM. The results showed that the particle size of periclase was larger when clinkers were calcined at higher temperatures or for longer time. Smaller periclase (2.60 μm) in LHC pastes tended to hydrate faster. As a result, expansion of LHC pastes develops relatively faster. Smaller particle of periclase in clinker tends to result in higher hydration degree of periclase in pastes cured at 20°C for 240 days, and there is a small amount of brucite appearing around periclase. The hydration rate of 4.00 μm periclase particle in cement paste cured at 80°C is obviously faster than that in paste cured at 20°C and 40°C. When cement paste was cured at 80°C for 7 days, the periclase was hydrated for 32.56%. The smaller size periclase (1–3 μm) had fully hydrated when the curing age was 240 days, and a large amount of brucite was produced around the larger periclase particle.

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Effect of Particle Size on Dielectric and Ferroelectric Properties of 0–3 Lead Magnesium Niobate Titanate-Portland Cement Composites

Ferroelectrics ◽

10.1080/00150193.2010.482899 ◽

2010 ◽

Vol 405 (1) ◽

pp. 98-104 ◽

Cited By ~ 8

Author(s):

R. Potong ◽

R. Rianyoi ◽

L. Jareansuk ◽

N. Jaitanong ◽

R. Yimnirun ◽

...

Keyword(s):

Particle Size ◽

Portland Cement ◽

Ferroelectric Properties ◽

Lead Magnesium Niobate ◽

Cement Composites ◽

Magnesium Niobate ◽

Lead Magnesium ◽

Effect Of Particle Size

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The Influence of Particle Size of Cement and Different Additives on the Properties of Portland Cement Pastes

Materials Science Forum ◽

10.4028/www.scientific.net/msf.851.104 ◽

2016 ◽

Vol 851 ◽

pp. 104-109 ◽

Cited By ~ 1

Author(s):

Pavel Šiler ◽

Iva Kolářová ◽

Tomáš Sehnal ◽

Roman Snop ◽

Tomáš Opravil ◽

...

Keyword(s):

Particle Size ◽

Fly Ash ◽

Portland Cement ◽

Raw Materials ◽

Cement Pastes ◽

Secondary Raw Materials ◽

Granulated Blast Furnace Slag ◽

Concrete Production ◽

Effect Of Particle Size ◽

Effective Use

The consumption of concrete as a building material is still increasing over the world. Concrete production is closely associated with CO2 and other greenhouse gases emissions. The reduction of these emissions can be achieved by a higher utilization of secondary raw materials in cement mixtures. Particle size is an important factor for more effective use of these materials. This work is focused on the calorimetric determination of the effect of particle size of cement, finely ground granulated blast furnace slag (GBFS), high-temperature fly ash (FA) and fluidized fly ash (FFA) on the Portland cement hydration. Effect of particle size on the hydration of pure cement pastes and pastes with the addition of secondary raw materials is monitored by isoperibolic calorimetry. Other part of this work is aimed on the mechanical properties of resulting materials. The flexural strength and compressive strength were observed after 1, 7 and 28 days of curing.

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