What does proper curing of concrete improve?

Proper curing of concrete significantly enhances its durability, which is the correct answer. Curing involves maintaining adequate moisture, temperature, and time for the concrete to achieve its desired strength and performance through hydration of the cement. When concrete is cured effectively, it allows the hydration process to continue for an optimal duration, which not only increases the compressive strength but also improves the overall durability of the final product.

Durable concrete is less susceptible to environmental damage such as freeze-thaw cycles, chemical erosion, and wear from traffic. Inadequate curing can lead to various issues, including cracking, reduced strength, and increased permeability, all of which detract from the concrete's lifespan and performance.

While setting time may be influenced during the curing process, it is not the primary focus or benefit; the setting time is mainly affected by the water-to-cement ratio and temperature conditions at the time of mixing and placing. Cohesion in the context of concrete relates to the internal bonding of its components but is not directly improved by curing. Lastly, while proper curing may minimally affect the appearance of concrete, including color, it is not a primary goal or a significant improvement provided by curing processes. Thus, focusing on durability captures the essence of why proper curing is essential in concrete