Recycled concrete exposed to high temperatures

2006 ◽  
Vol 58 (10) ◽  
pp. 675-682 ◽  
Author(s):  
C. J. Zega ◽  
A. A. Di Maio
Keyword(s):  
High Temperatures ◽  
Recycled Concrete

Residual properties of recycled concrete after exposure to high temperatures

2019 ◽  
Vol 71 (15) ◽  
pp. 781-793 ◽  
Author(s):  
Zongping Chen ◽  
Jianjia Chen ◽  
Fan Ning ◽  
Yi Li
Keyword(s):  
High Temperatures ◽  
Recycled Concrete ◽  
Residual Properties

Understanding the effect of recycled concrete aggregate and cementitious materials on concrete's fire resistance

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mohammed Ahmed Abed ◽  
Eva Lubloy
Keyword(s):  
Fly Ash ◽  
High Temperatures ◽  
Fire Resistance ◽  
Blended Cement ◽  
Cementitious Materials ◽  
Recycled Concrete ◽  
Supplementary Cementitious Materials ◽  
Concrete Aggregate ◽  
Recycled Concrete Aggregate ◽  
Content Type

PurposeFire can severely affect concrete structures and with knowledge of the properties of materials, the damage can be assessed. Aggregate, cement matrix and their interaction are the most important components that affect concrete behaviour at high temperatures. The effect of incorporating recycled concrete aggregate or cementitious materials, namely, cement type and pulverized fly ash, are reviewed to provide a better understanding of their involvement in fire resistance.Design/methodology/approachMore investigation research is needed to understand the fire resistance of such sustainable concrete that was already constructed. The present study illustrates the effect of using recycled concrete aggregate and cementitious materials on the fire resistance of concrete. To do so, a literature review was conducted and relevant data were collected and presented in a simple form. The author's selected research findings, which are related to the presents study, are also presented and discussed.FindingsRecycled concrete aggregate enhances the concrete behaviour at high temperatures when it substitutes the natural aggregate by reasonable substitution (more than 25–30%). It also almost eliminates the possibility of spalling. Moreover, utilizing both supplementary cementitious materials with recycled concrete aggregate can improve the fire resistance of concrete. The incorporation of pulverized fly ash and slag in Portland cement or blended cement can generally keep the mechanical properties of concrete at a higher level after heating to a high temperature.Originality/valueRecycled concrete aggregate enhances the concrete behaviour at high temperatures when it substitutes the natural aggregate by reasonable substitution (more than 25–30%). It also almost eliminates the possibility of spalling. Moreover, utilizing both supplementary cementitious materials with recycled concrete aggregate can improve the fire resistance of concrete. The incorporation of pulverized fly ash and slag in Portland cement or blended cement can generally keep the mechanical properties of concrete at a higher level after heating to a high temperature.

In situ REM imaging of surface processes on ceramic bulk crystals from 300 to 1670 K in a conventional TEM

1991 ◽  
Vol 49 ◽  
pp. 660-661
Author(s):  
Z. L. Wang ◽  
J. Bentley
Keyword(s):  
High Temperatures ◽  
Image Resolution ◽  
Atomic Processes ◽  
Crystal Surfaces ◽  
Beam Radiation ◽  
Surface Areas ◽  
Transmission Electron ◽  
Reflection Electron Microscopy ◽  
Gas Reactions

Studying the behavior of surfaces at high temperatures is of great importance for understanding the properties of ceramics and associated surface-gas reactions. Atomic processes occurring on bulk crystal surfaces at high temperatures can be recorded by reflection electron microscopy (REM) in a conventional transmission electron microscope (TEM) with relatively high resolution, because REM is especially sensitive to atomic-height steps.Improved REM image resolution with a FEG: Cleaved surfaces of a-alumina (012) exhibit atomic flatness with steps of height about 5 Å, determined by reference to a screw (or near screw) dislocation with a presumed Burgers vector of b = (1/3)<012> (see Fig. 1). Steps of heights less than about 0.8 Å can be clearly resolved only with a field emission gun (FEG) (Fig. 2). The small steps are formed by the surface oscillating between the closely packed O and Al stacking layers. The bands of dark contrast (Fig. 2b) are the result of beam radiation damage to surface areas initially terminated with O ions.

Green Concrete made with Recycled Concrete Aggregates: Fresh and Hardened Properties

2018 ◽  
Author(s):  
Driton R. Kryeziu ◽  
Armend Muja ◽  
Fisnik Kadiu ◽  
Visar Krelani ◽  
Besian Sinani ◽  
...  
Keyword(s):  
Recycled Concrete ◽  
Green Concrete ◽  
Concrete Aggregates ◽  
Recycled Concrete Aggregates ◽  
Hardened Properties

Handbook of recycled concrete and demolition waste

2013 ◽  
Author(s):  
F. Pacheco-Torgal ◽  
V. W. Y. Tam ◽  
J. A. Labrincha ◽  
Y. Ding ◽  
J. de Brito
Keyword(s):  
Recycled Concrete ◽  
Demolition Waste
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