Low-permeability concrete is critical to durable, long-lasting, and resilient infrastructure. During this webinar, we will discuss concrete basics and learn how different aspects of concrete mix designs impact concrete permeability. Then we will investigate why PRAs are so widely used, differentiate between PRAHs and PRANs, and identify when to use each type. Next, we will investigate how PRAHs work and how this behavior enables them to reduce concrete’s permeability and enhance strength and durability. We will also discuss a variety of PRAH applications and review recent projects involving the use of PRAHs.