Organic compounds, attack concrete

Some organic compounds, such as sugar solutions, attack concrete, presumably through complexing of Ca and consequent dissolution of CH and the hydrated silicate and aluminate phases. 

The hydrated components (C-S-H, portlandite, sulfoaluminates) in the cement matrix of concrete are in equilibrium with the pore liquid that is characterized by a high pH, due to the presence of OH (balanced by Na and K ). When concrete comes into contact with acid solutions, these compounds may dissolve at a rate that depends on the permeability of the concrete, the concentration and the type of acid. In soil with acidic ground water, the rate of refreshing is important Acids that can attack concrete are sulfuric acid, hydrochloric acid, nitric acid, organic acids such as acetic acid and humic adds and solutions of CO2. The rate of attack on the cement matrix depends on the solubility of the salts that are formed... 

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