Credit: BASF

Entrained air has been specified in all exterior concrete for many years to protect against freeze-thaw damage. But controlling the air content can be difficult and air reduces concrete strength. BASF has just made all of that a thing of the past with its new microsphere-based admixture. These microspheres are added to the concrete at the batch plant as a liquid admixture. The microspheres are very tiny hollow plastic spheres that are tough but flexible enough to allow ice to flow into them and thus protect the concrete from freeze-thaw damage and to eliminate the need for entrained air. BASF testing shows that the bubbles are stable and that the concrete is durable and easy to place and finish. This new admixture will be available nationwide in 2015. Visit