At Tolley Concrete, we love sharing with our customers new types of concrete, whether it’s geopolymer concrete, new ways to use concrete in architecture, or just an overall look at where we think the future of concrete is headed. Today, we’re bringing you some information on air entrainment in concrete and how that could affect the concrete’s strength. Read all about it down below.
Air-entrained concrete contains billions of microscopic air cells per cubic foot of space. These air pockets are there to relieve internal pressure in the concrete. They allow water to have room to escape when it freezes and expands. Air-entrained concrete is made with air-entrained portland cement, or by the introduction of other air-entraining agents in the onsite mixing of the concrete. The amount of entrained air is typically between four and seven percent of the volume of the concrete but could vary by the project’s purpose.
So why use air-entrained concrete in your project? It’s most commonly used to heighten freeze/thaw resistance, but can also be used for sulfate resistance, resistance to alkali-silica reactivity, and to increase workability. We’ll be talking about that last benefit today.
Air entrainment in concrete increases the workability of the material without much increase in the water/cement ratio. The downside here is that workability is inversely proportional to the concrete’s compressive strength. Just how much do those tiny air pockets affect the concrete’s strength, though?
Air entrainment is typically introduced when a higher workability is desired without much of a reduction in compressive strength. The exact amount of reduction in strength relies on many factors including mix proportions, type and grading of concrete, and the air-entraining agent itself. Typically, the loss of strength is between three and seven percent.
This innovation could be perfect for your project, but let the experts help you out on this one. Contact us today for a free quote. We’ll help you find the perfect materials for your project.