Aluminium Metal Reinforced Concrete – An Environmentally Friendly System with Infinite Service Life
By: Justnes, Harald
.
Publisher: Thane ACC LTD 2020Edition: Vol.94(1), Jan.Description: 24-29p.Subject(s): Civil EngineeringOnline resources: Click here
In:
Indian Concrete Journal - ICJSummary: Aluminium cannot be used to reinforce regular concrete since the high pH will attack the metal and evolve hydrogen gas. However, Al/5%Mg alloy is stable in concrete where 55% cement is replaced with calcined clay in the concrete mix. Replacing high fraction of clinker burnt at 1450ºC, and with high CO2emission from limestone decomposition in the raw meal, with a clay calcined at 850ºC obtainable by biofuel give obvious savings in energy and CO2 emissions. Furthermore, since aluminium can withstand carbonation and chlorides a cover of only 20 mm for mechanical interaction with reinforcement is needed resulting in a smaller concrete volume. Binder with 55% calcined clay is sulphate resistant and do not induce AAR due to lower pH and no remaining calcium hydroxide in the system. The only degradation mechanism left is freeze-thaw avoidable by proper air entrainment. Thus, in theory an infinite service life without maintenance may be at hand for aluminium metal reinforced concrete.
| Item type | Current location | Call number | Status | Date due | Barcode | Item holds |
|---|---|---|---|---|---|---|
Articles Abstract Database
|
School of Engineering & Technology (PG) Archieval Section | Not for loan | 2021-2022296 |
Aluminium cannot be used to reinforce regular concrete since the high pH will attack the metal and evolve hydrogen gas. However, Al/5%Mg alloy is stable in concrete where 55% cement is replaced with calcined clay in the concrete mix. Replacing high fraction of clinker burnt at 1450ºC, and with high CO2emission from limestone decomposition in the raw meal, with a clay calcined at 850ºC obtainable by biofuel give obvious savings in energy and CO2 emissions. Furthermore, since aluminium can withstand carbonation and chlorides a cover of only 20 mm for mechanical interaction with reinforcement is needed resulting in a smaller concrete volume. Binder with 55% calcined clay is sulphate resistant and do not induce AAR due to lower pH and no remaining calcium hydroxide in the system. The only degradation mechanism left is freeze-thaw avoidable by proper air entrainment. Thus, in theory an infinite service life without maintenance may be at hand for aluminium metal reinforced concrete.
Click on an image to view it in the image viewer
There are no comments for this item.