SEM Image Analysis in Permeable Recycled Concretes with Silica Fume. A Quantitative Comparison of Porosity and the ITZ

Recycled aggregates (RA) from construction and demolition can be used in permeable concretes (PC), improving the environment. PCs have a significant porous network, their cement paste and the interaction between the paste and the RA establishing their strength. Therefore, it is important to evaluate...

Full description

Saved in:
Bibliographic Details
Published in:Materials 2019-07, Vol.12 (13), p.2201
Main Authors: Chinchillas Chinchillas, Manuel de Jesús, Rosas Casarez,, Carlos Antonio, Arredondo Rea, Susana Paola, Gómez Soberón, José Manuel Vicente, Corral Higuera, Ramón
Format: Article
Language:English
Subjects:
Additius
Additives
Aggregates
Cement hydration
Cement paste
Chemical elements
Ciment
Concrete
Demolition
Edificació
Formigó
Image analysis
interfacial transition zone
Laboratories
Materials de construcció
Permeability
permeable concrete
Physical properties
porosimetry mercury intrusion
Porositat
Porosity
Productes reciclats
recycled aggregates
Recycled materials
Recycled products
Scanning electron microscopy
Silica fume
Silicon dioxide
Àrees temàtiques de la UPC
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Recycled aggregates (RA) from construction and demolition can be used in permeable concretes (PC), improving the environment. PCs have a significant porous network, their cement paste and the interaction between the paste and the RA establishing their strength. Therefore, it is important to evaluate the porosity in the interfacial transition zones. The porosity of the cement paste, the aggregate and the interfacial transitional zones (ITZ) of a PC with recycled coarse aggregates (RCA) and silica fume (SF) is measured by means of image analysis-scanning electron microscope (IA)-(SEM) and by mapping the chemical elements with an SEM-EDS (energy dispersive spectrometer) detector microanalysis linked to the SEM and, as a contrast, the mercury intrusion porosimetry technique (MIP). In the IA process, a "mask" was created for the aggregate and another for the paste, which determined the porosity percentage (for the anhydrous material and the products of hydration). The results showed that using SF caused a reduction (32%) in the cement paste porosity in comparison with the PC with RA. The use of RA in the PC led to a significant increase (190%) in the porosity at different thicknesses of ITZ compared with the reference PC. Finally, the MIP study shows that the use of SF caused a decrease in the micropores, mesopores and macropores.
ISSN:1996-1944
1996-1944
DOI:10.3390/ma12132201