Winter has arrived early and that brings up questions about pouring concrete in cold weather. Yes, it can be done. In fact, concrete is routinely poured in cold weather. But certain measures must be taken to ensure the concrete gains the desired strength and does the job that it was intended to do.

If you are pouring concrete in cold weather, weather where the average daily temperature does not exceed forty degrees farenheit, your concrete is considered “Cold Weather Concrete.” The American Concrete Institute has specific guidelines for how to pour cold weather concrete. Their document ACI 306 spells out the things that should be done. Warming the reinforcing steel, mixing the concrete with hot water, adding accelerating agents to the mix, covering the concrete with insulating blankets, and adding more cement to the mix to strengthen the concrete and speed up the curing time are all methods for overcoming the potential problems with pouring concrete in cold weather. (more…)

Up until now, concrete cracks have been the nemesis of the construction industry. In fact, there’s an old joke that there are two types of concrete. The first type is concrete that has cracked. The second type is concrete that hasn’t cracked…yet. But is there something new on the way?

Concrete “flatwork,” that is, concrete poured in slabs for floors, sidewalks, driveways, and roads, is particularly prone to cracking. It will shrink as it “cures” and crack. And it will continue to swell and shrink when it gets warmer or cooler and be susceptible to developing more cracks. (more…)