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Pro101

CHANGES OF THE MATERIAL PROPERTIES BY SELECTIVE CARBONATION OF RECYCLED AGGREGATES FROM CONCRETE



Author(s): Dipl.-Ing. Marko Seidemann, Prof. Dr.-Ing. habil. Anette Müller, Prof. Dr.-Ing. Horst-Michael Ludwig
Book Title: III Progress of Recycling in the Built Environment
Editor: I. Martins, C. Ulsen and S. C. Angulo
e-ISBN: 978-2-35158-158-2
Publisher: RILEM Publications SARL
Publication year: 2015
Pages: 37-42
Total Pages: 8
Language: English


Abstract: The aim of this work is to bind a maximum of carbon dioxide in concrete recyclates permanently by means of a selective carbonation. This process is meant to change the properties of the recyclate in such a way that it comes to a decrease in porosity and to an increase in strength. The carbonation process is a well-known procedure. As diffusion-steered process it runs, however, very slowly and takes years. The technical challenge of this work is to accelerate the carbonation reaction in a reactor and thus making it technically usable. A test device was developed for the directed carbonation. It consists of a tubular reactor and several measuring units. The test specimens are continuously subjected to a preset gas mixture in the tubular reactor. The gas flows evenly through the reactor. The first tests were carried out on cement stone at varying CO2-concentrations over different time intervals. The results show a correlation of the samples weight increase and their density after staying in the reactor. The CO2 absorption was confirmed by means of thermal analysis after the carbonation. In further tests a carbonation of concrete recyclates was carried out. The treated and the untreated concrete recyclates as well as the natural aggregate were taken to produce concretes. Then they were characterized as to their fresh concrete properties as well as their hardened concrete properties and both compared and evaluated to one another.


Online publication: 2015
Publication Type: full_text
Public price (Euros): 0.00