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The alkali–silica reaction (ASR), also commonly known as concrete cancer, [3] is a deleterious internal swelling reaction that occurs over time in concrete between the highly alkaline cement paste and the reactive amorphous (i.e., non-crystalline) silica found in many common aggregates, given sufficient moisture.
The alkali–silica reaction (ASR) is a deleterious chemical reaction between the alkali (Na 2 O and K 2 O), dissolved in concrete pore water as NaOH and KOH, with reactive amorphous (non-crystalline) siliceous aggregates in the presence of moisture. The simplest way to write the reaction in a stylized manner is the following (other ...
Alkali–carbonate reaction. The alkali–silica reaction is the most common form of alkali–aggregate reaction. Two other types are: the alkali–silicate reaction, in which layer silicate minerals (clay minerals), sometimes present as impurities, are attacked, and; the alkali–carbonate reaction, which is an uncommon attack on certain ...
It can also be of advantage for cement quality reasons, since it reduces the alkali content of the clinker. The alkali content is a critical property of cement. Indeed, cement with a too high alkali content can cause a harmful alkali–silica reaction (ASR) in concrete made with aggregates containing reactive amorphous silica.
[citation needed] Other forms of damage include alkali-silica reaction (ASR), chemical intrusion, and corrosion of steel reinforcements. Types.
Alkali–silica reaction (ASR), also known as alkali-aggregate reaction (AAR), when reactive amorphous silica aggregates exposed to alkaline conditions (high pH) swell inside the concrete matrix leading to the development of a network of cracks. It may also refer to:
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A similar reaction to above, also catalysed by sodium hydroxide, is the alkali–silica reaction, a slow degradation process causing the swelling and the cracking of concrete containing aggregates rich in reactive amorphous silica. In a very similar way, sodium hydroxide greatly facilitates the dissolution of the amorphous silica.