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The ancient Romans used a type of lime mortar that has been found to be self-healing. [8] The stratlingite crystals form along the interfacial zones of Roman concrete, binding the aggregate and mortar together and this process continued even after 2000 years and it was discovered by the geologist Marie Jackson and her colleagues in 2014.
The first signs of this effect were discovered by a British pharmacist who noticed that his wife, who at the time was on MAOI medication, had severe headaches when eating cheese. [38] For this reason, it is still called the "cheese reaction" or "cheese crisis", although other foods can cause the same problem.
Therefore, the volume of the fresh and very young concrete undergoes a contraction due to the hydration reaction: it is what is called "chemical shrinkage" or "self-desiccation". It is not a problem as long as the very fresh concrete is still in a liquid, or a sufficiently plastic, state and can easily accommodate volume changes (contraction).
Ricotta (Italian:) is an Italian whey cheese made from sheep, cow, goat, or Italian water buffalo milk whey left over from the production of other cheeses. Like other whey cheeses, it is made by coagulating the proteins that remain after the casein has been used to make cheese, notably albumin and globulin .
Several mechanisms have been identified by which bacteria can induce the calcium carbonate precipitation, including urea hydrolysis, denitrification, sulfate production, and iron reduction. [5] Two different pathways, or autotrophic and heterotrophic pathways, through which calcium carbonate is produced have been identified.
The alkali-silica reaction mechanism catalysed by a soluble strong base as NaOH or KOH in the presence of Ca(OH) 2 (alkalinity buffer present in the solid phase) can be compared with the carbonatation process of soda lime. The silicic acid (H 2 SiO 3 or SiO 2) is simply replaced in the reaction by the carbonic acid (H 2 CO 3 or CO 2).
The fracture energy of a living building material compared with two controls: one with no cyanobacteria, and one with no cyanobacteria and a high pH. [2]Self-replicating concrete is produced using a mixture of sand and hydrogel, which are used as a growth medium for synechococcus bacteria to grow on.
A fairly well-defined reaction front can often be observed in thin sections; ahead of the front the concrete is normal, or near normal. Behind the reaction front, the composition and the microstructure of concrete are modified. These changes may vary in type or severity but commonly include: Extensive cracking; Expansion