What happens to the performance of concrete if air content is reduced?

When air content in concrete is reduced, the performance of the concrete is affected in significant ways, particularly its durability and resilience against environmental factors. Lowering the air content typically results in decreased resistance to freeze-thaw cycles. Air entrainment in concrete is crucial because it creates small air pockets that allow for expansion during freezing. Without sufficient entrained air, water that freezes within the concrete can create internal pressures, leading to cracking and spalling.

In environments where freeze-thaw conditions are common, sufficient air content is essential to protect the concrete structure from damage. Thus, reduced air content compromises the concrete’s ability to withstand these cycles, making it more susceptible to deterioration over time. Maintaining appropriate air content is vital for enhancing the durability and longevity of concrete in harsh conditions.