Concrete additives have been used since Roman and Egyptian times, when it was discovered that adding volcanic ash to the mix allowed it to set underwater. Similarly, the Romans knew that adding horse hair made concrete less liable to crack while it hardened, and adding blood made it more frost-resistant! Today, engineers have created other materials to create concrete with improved properties, such as higher strength or electrical conductivity. Qualified Concrete utilizes common additives such as:

• Accelerators: Speeds up the curing process, used in cold-climate or paving repairs
• Retarders: Slows the hydration of the concrete
• Plasticizers: Improves workability and provides a more even distribution of the binder particles without increasing water content