can you please explain us about what are the minimum thicknesses for pcc in proportions for all the civil works i,e from raft to finishing of a building?

Answer:

PCC, or Plain Cement Concrete, is often used in the construction process as a base for other materials or structures. Its thickness varies depending on the type of work and the expected load on it. However, it's important to note that final decisions about thickness should be made by a competent engineer, taking into account the specific circumstances of the project.

Here are some general guidelines:

1. Footings: For residential buildings, PCC in footings is usually around 150mm (6 inches). For commercial buildings or buildings with heavy loads, it can be more than 150mm.

2. Raft or Mat Foundations: PCC thickness generally ranges between 75mm (3 inches) to 150mm (6 inches).

3. Ground or Basement Slab: For ground floor slabs and basement slabs, the PCC layer is typically between 100mm (4 inches) to 150mm (6 inches).

4. Road Pavements: For pavements, the PCC thickness will depend on the expected traffic load. It can range from 150mm (6 inches) for light traffic to 300mm (12 inches) or more for heavy traffic.

5. Roof Slab or Terrace: PCC layer is generally not used directly on the roof slab or terrace. Waterproofing is typically provided here. However, for any additional screed or protective layer, it can be 20mm to 40mm.

6. Finish: For finishes like plastering, it’s usually between 12mm to 25mm.

I hope this helps. There are load calculations, soil bearing capacity, exposure conditions and other factors to be considered to decide the thickness and mix of PCC.

Let me know if you have follow-up questions.