Primary particle size and agglomerate size effects of amorphous silica in ultra-high performance concrete

2013 ◽  
Vol 37 ◽  
pp. 61-67 ◽  
Author(s):  
Tina Oertel ◽  
Frank Hutter ◽  
Ricarda Tänzer ◽  
Uta Helbig ◽  
Gerhard Sextl
Keyword(s):  
Particle Size ◽  
Amorphous Silica ◽  
Size Effects ◽  
High Performance ◽  
Primary Particle ◽  
High Performance Concrete ◽  
Primary Particle Size ◽  
Ultra High Performance Concrete ◽  
Agglomerate Size

Influence of amorphous silica on the hydration in ultra-high performance concrete

2014 ◽  
Vol 58 ◽  
pp. 121-130 ◽  
Author(s):  
Tina Oertel ◽  
Uta Helbig ◽  
Frank Hutter ◽  
Holger Kletti ◽  
Gerhard Sextl
Keyword(s):  
Amorphous Silica ◽  
High Performance ◽  
High Performance Concrete ◽  
Ultra High Performance Concrete

scholarly journals The Influences of Iron Ore Tailings as Fine Aggregate on the Strength of Ultra-High Performance Concrete

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Zhigang Zhu ◽  
Beixing Li ◽  
Mingkai Zhou
Keyword(s):  
Particle Size ◽  
Frost Resistance ◽  
High Performance ◽  
Iron Ore ◽  
High Performance Concrete ◽  
Fine Aggregate ◽  
Ultra High Performance Concrete ◽  
Iron Ore Tailings ◽  
Better Than

The present study looks for the feasibility of preparing UHPC with iron ore tailings (IOT for short) as fine aggregate. To enhance outstanding high performances, some influences on UHPC mortars were investigated such as different kinds of sands, different mix ratio of sands, and different largest particle size of fine aggregate. The results show that IOT have negligible poorer aggregate performance than silica sands but better than river sands. The strength of UHPC reaches the highest point when silica sands were instead 60% by IOT. As the largest particle size of fine aggregate is decreasing, the strength and frost resistance of UHPC were improved, but the liquidity was decreased. Micropowder of IOT affects the strength and the optimal content was 4%.

Effect of Ball Milling on the Properties of Zirconia Powder Prepared by Alcohol-Aqueous Coprecipitation Method

2013 ◽  
Vol 544 ◽  
pp. 34-37 ◽  
Author(s):  
Yun Feng Zhang ◽  
Kai Jun Wang ◽  
Jin Hu
Keyword(s):  
Particle Size ◽  
Ball Milling ◽  
Primary Particle ◽  
Raw Materials ◽  
Primary Particle Size ◽  
Zirconia Powder ◽  
Agglomerate Size ◽  
Coprecipitation Process ◽  
Aqueous Method ◽  
Zirconia Powders

Zirconia precursor was prepared by an alcohol-aqueous coprecipitation process from raw materials of ZrOC12•8H2O and ammonia ,the zirconia powders were subsequently obtained by calcination of the precursor at 600°C and ball milling. The properties of zirconia powder prepared by alcohol-aqueous method after ball-milling had been researched by BET,XRD,TEM and laser granularity instrument.The results show that by using ball-milling the agglomerate size can be effectively decreased but the primary particle size is hardly affected .The surface area of powder after calcinated can be markedly increased and narrowed size distribution can be gained by ball-milling, but the phase structure of the powder had not been changed.

Electrically Controlled Flame Synthesis of Nanophase TiO2, SiO2, and SnO2 Powders

1997 ◽  
Vol 12 (4) ◽  
pp. 1031-1042 ◽  
Author(s):  
Srinivas Vemury ◽  
Sotiris E. Pratsinis ◽  
Lowinn Kibbey
Keyword(s):  
Particle Size ◽  
Electric Fields ◽  
Primary Particle ◽  
Particle Growth ◽  
Primary Particle Size ◽  
Flame Synthesis ◽  
High Temperature Region ◽  
Hydrocarbon Flames ◽  
Agglomerate Size ◽  
Electrically Assisted

Nanophase particles with precisely controlled characteristics are made by oxidation of their halide vapors in electrically assisted hydrocarbon flames using needle-shaped or plate electrodes. The particle size and crystallinity decrease with increasing field strength across the flame. The field generated by the electrodes across the flame decreases the particle residence time in the high temperature region of the flame. Furthermore, it charges the newly formed particles, resulting in electrostatic repulsion and dispersion that decreases particle growth by coagulation. Electric fields reduced the primary particle size of TiO2, the agglomerate size of SnO2, and both the agglomerate and primary size of SiO2.

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