The maximum spacing of vertical reinforcement in an RCC (Reinforced Cement Concrete) wall should not exceed 3 times the thickness of the wall. This means that the distance between two adjacent vertical reinforcement bars should not be more than 3 times the thickness of the wall.

Explanation:

1. Importance of vertical reinforcement in RCC walls:
- RCC walls are subjected to various loads and forces such as gravity loads, wind loads, and earthquake loads.
- Vertical reinforcement bars help to resist these loads and provide strength and stability to the wall.
- They also help in preventing crack formation and improving the overall durability of the wall.

2. Spacing of vertical reinforcement:
- The spacing of vertical reinforcement bars is an important factor in determining the strength and stability of the wall.
- If the spacing is too large, it can lead to inadequate reinforcement and reduced strength of the wall.
- On the other hand, if the spacing is too small, it can increase the construction cost and may not provide any additional benefits.

3. Maximum spacing limit:
- The maximum spacing of vertical reinforcement in an RCC wall is specified to ensure adequate strength and stability.
- The limit of 3 times the thickness of the wall is a commonly accepted standard in the construction industry.
- This limit ensures that there is sufficient reinforcement throughout the height of the wall to resist the applied loads.
- It also helps in preventing excessive cracking and deflection in the wall.

4. Practical considerations:
- The maximum spacing limit may vary depending on the design requirements and the specific conditions of the structure.
- In some cases, engineers may choose to reduce the spacing below the maximum limit to enhance the strength and performance of the wall.
- The type and size of the reinforcement bars used also play a role in determining the spacing.
- It is important to follow the guidelines provided by the design engineer or relevant building codes to ensure the proper spacing of vertical reinforcement bars.

In conclusion, the maximum spacing of vertical reinforcement in an RCC wall should not exceed 3 times the thickness of the wall to ensure adequate strength, stability, and durability of the structure.