One hectare comprises between 1.2 and 1.6 football pitches, as soccer fields are known in British English. An internationally-sanctioned soccer field is 100 to 110 meters in length by 64 to 75 meters in width, comprising between 0.62 and 0.82 hectares depending on the field. Keep Learning.
From Wikipedia, the free encyclopedia. Alkaliâaggregate reaction is a term mainly referring to a reaction which occurs over time in concrete between the highly alkaline cement paste and non-crystalline silicon dioxide, which is found in many common aggregates.he alkaliâaggregate reaction is a general, but relatively vague, expression which can lead to confusion. More precise definitions include the following: 1  Alkaliâsilica reaction (ASR, the most common reaction of this type); 2  Alkaliâsilicate reaction, and; 3  Alkaliâcarbonate reaction.
In chemistry, an alkali (/ËÃ¦lkÉlaÉª/; from Arabic: al-qaly Ø§ÙÙÙÙ, Ø§ÙÙØ§ÙÙ , âashes of the saltwortâ) is a basic, ionic salt of an alkali metal or alkaline earth metal chemical element. An alkali also can be defined as a base that dissolves in water. A solution of a soluble base has a pH greater than 7.0. The adjective alkaline is commonly, and alkalescent less often, used in English as a synonym for basic, especially for bases soluble in water.