Microstructure and performance of fly ash micro-beads in cementitious material system

Abstract In this work, we highlight the often-overlooked effects of doping on the microstructure and performance of bulk thermoelectric materials to offer a broader perspective on how dopants interact with their parent material. Using PbSe doped with Na, Ag, and K as a model material system, we combine original computational, experimental, and microscopy data with established trends in material behavior, to provide an in-depth discussion of the relationship between dopants, processing, and microstructure, and their effects on thermoelectric efficiency and thermal stability. Notable observations include differences in the microstructure and mass loss of thermally treated samples of Na- and Ag-doped PbSe, as well as findings that Na and K cations exist predominantly as substitutional point defects while Ag also occupies interstitial sites and exhibits lower solubility. We discuss how these differences in point defect populations are known to affect a dopants’ ability to alter carrier concentration and how they may affect the mechanical properties of PbSe during processing. Graphic Abstract

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Effects of Packing Density and Calcium- Silicon Ratio of Ternary Cementitious Material System on Strength of Reactive Powder Concrete

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.261-263.197 ◽

2011 ◽

Vol 261-263 ◽

pp. 197-201

Author(s):

Tao Ji ◽

Bao Chun Chen ◽

Feng Li ◽

Yi Zhou Zhuang ◽

Zhi Bin Huang ◽

...

Keyword(s):

Fly Ash ◽

Silica Fume ◽

Packing Density ◽

Cementitious Material ◽

Reactive Powder Concrete ◽

Material System ◽

Mix Proportion ◽

Study Results ◽

Calcium Silicon ◽

Reactive Powder

Aim & Goff model was used to predict the packing density of cementitious material including cement, ultra-pulverized fly ash and silica fume. The mix proportions of reactive powder concrete (RPC) with different packing density and calcium-silicon ratio of cementitious material were designed, and a strength test was carried out. The study results reveal that the flexural strength and compressive strength of RPC are related to the packing density and calcium-silicon ratio of cementitious material. For the mix proportion of RPC with the calcium-silicon ratio of 1.179, calcium hydroxide reacts with silicon dioxide fully, and the superfluous ultra-pulverized fly ash and silica fume fill the voids of RPC. The packing density of its cementitious material is the largest, and its strength approaches summit.

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Study on the Density and Performance of Cementitious Materials Compounded by Multiple Mineral Admixtures

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.374-377.1446 ◽

2011 ◽

Vol 374-377 ◽

pp. 1446-1450

Author(s):

Hui Xu ◽

An Qi Lu

Keyword(s):

Compressive Strength ◽

Fine Particles ◽

Cementitious Materials ◽

Cementitious Material ◽

Mineral Admixtures ◽

Material System ◽

Cement Pastes ◽

And Performance ◽

Multiple Mineral ◽

Ultra Fine Particles

This paper studies on the relative denseness of fresh cement pastes compounded with multi-cementitious materials and the performances of their harden concretes. Results show that with the dense packing of several ultra-fine particles, higher the relative denseness of different cementitious material system, higher the compressive strength and lower the air permeability of the harden concrete. The multi-cementitious material compounded by 37% cement、20% fly ash、40% pulverized slag and 3% silica fume has the higher relative denseness of fresh cement paste, and its compressive strength and air permeation of harden concrete composite is also improved.

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Hydration Mechanism and Performances of Tri–Cementitous Materials System Compounded with Clinker Limestone Powder and Fly Ash

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.150-151.1741 ◽

2010 ◽

Vol 150-151 ◽

pp. 1741-1744

Author(s):

Yun Fen Hou ◽

Tian Yong Huang ◽

Shao Min Song

Keyword(s):

Compressive Strength ◽

Fly Ash ◽

Cementitious Material ◽

Limestone Powder ◽

Curing Time ◽

Hydration Mechanism ◽

Particles Size Distribution ◽

Mixed Material ◽

And Performance ◽

Water Amount

Hydration mechanism and performance of tri-cementitious material, which contains clinker, limestone powder and fly ash, are studied. It is showed that when mixed materials ratio increases from 20% to 40%, the water amount for standard consistency will increase remarkably, and when dosage of limestone powder is 50% in mixed material, the water amount for standard consistency will reach minimum, i.e. 26%; but when limestone powder ratio reaches 40%, the fluidity of slurry reaches maximum, and then it drops with increasing of limestone powder ratio. It is also found that increasing of dosages of mixed materials will decrease flexural strength and compressive strength, and increasing of ratio of limestone powders can result in decreasing of compressive strength at 28 days curing time, especially when ratio of mixed material is 20%. In order to explain the rules that above-mentioned, the particles size distribution is studied, and the hydration mechanism is analyzed.

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Systematic study on the basic characteristics of alkali-activated slag-fly ash cementitious material system

Construction and Building Materials ◽

10.1016/j.conbuildmat.2011.09.021 ◽

2012 ◽

Vol 29 ◽

pp. 482-486 ◽

Cited By ~ 23

Author(s):

Xin Luo ◽

Jinyu Xu ◽

Erlei Bai ◽

Weimin Li

Keyword(s):

Fly Ash ◽

Systematic Study ◽

Cementitious Material ◽

Material System ◽

Alkali Activated Slag ◽

Basic Characteristics ◽

Activated Slag ◽

Alkali Activated

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Investigation on a New Hydraulic Cementitious Binder Made from Phosphogypsum

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.864-867.1923 ◽

2013 ◽

Vol 864-867 ◽

pp. 1923-1928

Author(s):

Yue Xu ◽

Jian Xi Li ◽

Li Li Kan

Keyword(s):

Compressive Strength ◽

Fly Ash ◽

Active Carbon ◽

High Strength ◽

Tricalcium Silicate ◽

Dicalcium Silicate ◽

Cementitious Material ◽

Saturation Ratio ◽

Tricalcium Aluminate ◽

Cementitious Binder

A new kind of high strength cementitious material is made from phosphogypsum (PG), active carbon and fly-ash. Through the orthogonal research, it was showed that the calcination temperature, retention time, dosage of active carbon and fly ash on the compressive strength of cementitious binder are the most important. The result also showed that, in the conditions of temperature 1200°C, time retention 30 min, dosage of active carbon 10%, dosage of fly ash 5%, the compressive strength of the cementitious material for 3d and 28d could reach to 46.35MPa and 92.70MPa, the content of sulfur trioxide was 11.60% accordingly. A lot of active mineral materials, such as dicalcium silicate, tricalcium silicate, tricalcium aluminate were formed in the calcination. The C-S-H gel, calcium hydroxide and ettringite were found in 3d and 28d hydrates. It is found that the lime saturation ratio and silica modulus need to be control between 0.40~0.65 and 4~8 in order to produce high strength cementitious material.

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