The Ontario Building Code | Concrete in Contact with Sulfate Soil
9.3.1.3. Concrete in Contact with Sulfate soil
(1) Concrete in contact with sulfate soil, which is deleterious to normal cement, shall conform to the requirements in Clause 4.1.1.6. of CSA A23.1, "Concrete Materials and Methods of Concrete Construction".
In Plain Language
Concrete in contact with sulfate-containing soil needs special cement types or protective measures set out in this article, since sulfates can chemically attack and deteriorate ordinary concrete over time.
This is a plain-language summary of the 2012/2017 Ontario Building Code text above, for general understanding only and not a substitute for the Code. Always confirm current requirements against the 2024 edition (O.Reg. 163/24) or a qualified professional before construction.