R402.2

Section R402.2 is titled 'Concrete' and covers the requirements for concrete compressive strength and composition in foundations, walls, and slabs. The minimum compressive strength based on location and weathering potential (via a cross-referenced table), the maximum allowed mixture of certain materials based on a cross-reference to another standard, and a cross-reference to another standard for materials used to produce and test concrete is established. The purpose of this section is to prevent structural failure. Note that the cross-referenced table has footnotes, one of which says that the strength is at 28 days, meaning the concrete needs to cure for 28 days before being tested. Should construction on top of the foundation begin before the concrete testing has been completed⸮

The model shows a concrete cylinder being tested for compressive strength.