Will my concrete crack?

Short answer? Yes.

Concrete is an extremely strong material, but it is not immune to cracking.

The first cracks you will see are shrinkage cracks during curing. Differences in temperature, humidity, and wind cause this. Varied thicknesses and base material used also contribute. Shrinkage cracks rarely affect the integrity of the concrete.

Cracks are inevitable, but if you take proactive steps, like proper base preparation you can significantly reduce the amount that occur. Curing practices also have a big impact and what is referred to as "wet curing" is commonly used. This is just doing things like putting straw on top of your concrete and spraying it down with water to keep it cool and hydrated as it cures. Burlap and sprinklers are standard practice on bridge decks but doing this on residential projects would take an extra day of labour and so would cost more. On projects with a broomed finish it is important that this practice is not started immediately after it has been broomed as it will wreck the finish.

Another thing that plays a part in concrete cracking is the concrete mix itself. Water quantity, chemical additives and the temperature of the mix all matter.

Saw cutting is a standard practice that happens within 16-24 hours of your project has been poured and finished. The goal with this is to control shrinkage cracking and essentially chose where the cracks are going to be. Concrete doesn't always follow the "rules" however and won't necessarily crack on your premade cracks. In the case of smaller projects like sidewalks, the cuts can be tooled right into the concrete during the finishing process.

Ultimately, there is no way to completely prevent your concrete from cracking but it can be minimized with a few different practices.