For reinforced concrete members totally immersed in seawater, the cover shall be 40 mm more than that.

Reinforced cement concrete members that are totally immersed in seawater are exposed to several factors that can cause corrosion and deterioration of the concrete. To prevent this, an additional cover thickness is required.

Reason for Additional Cover Thickness

The main reason for providing additional cover thickness in reinforced cement concrete members that are totally immersed in seawater is to protect the reinforcement from corrosion. Seawater contains salts and other chemicals that can penetrate the concrete and reach the reinforcement. This can cause the reinforcement to corrode, which can weaken the structure and reduce its service life.

Factors Affecting Additional Cover Thickness

The additional cover thickness required for reinforced cement concrete members that are totally immersed in seawater depends on several factors, including:

1. Type of seawater: The additional cover thickness required may vary depending on the type of seawater. Seawater in different locations can have different levels of salinity, temperature, and other chemicals that can affect the rate of corrosion.

2. Exposure conditions: The exposure conditions of the reinforced cement concrete member can also affect the additional cover thickness required. For example, if the member is exposed to waves and tidal action, it may require a thicker cover compared to a member that is submerged in calm water.

3. Design life: The design life of the structure can also affect the additional cover thickness required. If the structure is designed to last for a longer period, it may require a thicker cover to provide adequate protection against corrosion.

Importance of Additional Cover Thickness

Providing adequate additional cover thickness in reinforced cement concrete members that are totally immersed in seawater is crucial to ensure the long-term durability and safety of the structure. Some of the key benefits of providing additional cover thickness include:

1. Protection against corrosion: The additional cover thickness provides a barrier between the reinforcement and seawater, preventing corrosion and prolonging the service life of the structure.

2. Improved durability: The additional cover thickness can improve the durability of the structure, reducing the need for costly repairs and maintenance.

3. Enhanced safety: A thicker cover can also improve the safety of the structure by reducing the risk of failure due to corrosion and deterioration.

Conclusion

In conclusion, the additional cover thickness required in reinforced cement concrete members that are totally immersed in seawater is an important factor that needs to be considered during the design and construction of marine structures. Adequate cover thickness can protect the reinforcement from corrosion, improve the durability of the structure, and enhance its safety and service life. The recommended additional cover thickness for such structures is 40 mm.