The Ultimate Creep Coefficient for Concrete

Definition:

The ultimate creep coefficient for concrete is defined as the ratio of the ultimate creep strain to the elastic strain.

Effect of Age of Loading:

The value of the ultimate creep coefficient for concrete decreases with the age of loading. This means that as time passes, the creep strain increases while the elastic strain decreases. The ultimate creep strain is a function of the age of loading, and it increases with time.

This effect can be attributed to the fact that as time passes, the microcracks in the concrete begin to propagate, leading to an increase in creep strain. Additionally, the hydration process of the cement paste continues, leading to a decrease in the elastic modulus, which further contributes to a decrease in the ultimate creep coefficient.

Other Factors Affecting the Ultimate Creep Coefficient:

In addition to the age of loading, the ultimate creep coefficient for concrete is affected by other factors such as:

- Concrete mix design: The type and proportion of the cement, aggregates, and water used in the mix can affect the ultimate creep coefficient.
- Moisture content: The moisture content of the concrete can affect the ultimate creep coefficient, with wetter concrete having a higher ultimate creep coefficient.
- Temperature: The temperature of the concrete can affect the ultimate creep coefficient, with higher temperatures leading to a higher ultimate creep coefficient.

Conclusion:

In conclusion, the ultimate creep coefficient for concrete is an important parameter that affects the long-term behavior of concrete structures. Its value decreases with the age of loading and is affected by various factors such as concrete mix design, moisture content, and temperature. It is important to consider these factors when designing concrete structures to ensure their long-term durability and performance.