Table 1.

Summary of causes of deterioration of concrete structures exposed to contaminated soil [6,7,8,9].

Causes of Deterioration	Deterioration Type
Caused by concrete components	Alkali–silica reaction (ASR): It is one of the most concerning topics regarding the durability of concrete, leading to costly maintenance and rehabilitation works. ASR occurs when cement aggregates react with the alkali hydroxides in concrete, producing a hygroscopic gel that in the presence of water causes an expansion and thus the cracking of the concrete surface Corrosion of steel bars: The corroded bars occupy a greater volume than the non-corroded ones, causing cracking and delamination of the concrete surface. Steel corrosion is caused by the presence of chloride ions or carbon dioxide.
Caused by external agents	Chemical corrosion: It can be divided into two groups: i. Chemicals that promote a rapid deterioration: Aluminum chloride, calcium bisulfite, hydrochloric acid, nitric acid, and sulfuric acid. ii. Chemicals that produce a moderate deterioration: aluminum sulfate, ammonium bisul-fate, ammonium nitrate, ammonium sulfate, ammonium sulfide, and sodium bisulfate. Volume changes: Freeze–thaw cycles, plastic and drying shrinkage, and thermal changes are the leading causes of volumetric change.