Sub-base Thickness for Slab on Grade

Determine it based on the local regulations and codes, or per the specification referenced by them.

Have you consulted the local code compliance officer?

Where are you?

I'm in Malaysia and using British Standard for Code of this project, I need to calculate sub-base course thickness for that ground floor slab, but i didn't find any explanation for it in BS Code so far.
if any other Code for this design, please let me know

amar89,

I'm not sure about the British Code, but there are other codes and references available to you.

Here's a link for a US Army Technical Manual regarding concrete slabs on grade, that you can download for free:

rmypubs.army.mil/eng/DR_pubs/DR_a/pdf/tm5_809_12.pdf

U.S. Army TM-5-809-12 "Concrete Floor Slabs on Grade Subjected to Heavy Loads".

Also, if you can located it online, download a ebook copy of "Foundation Analysis and Design", by Joesph E. Bowles, P.E.. This particular textbook is very useful because it uses both US (English) units and Metric units.

Additionally, The Portland Cement Association (PCA) use to publish an engineering guide for the design of concrete pavements. For the life of me I cannot remember the exact title of it.....give me some time and I'll try to locate it in my extensive professional library.

Also, check out the website below, which contains a concrete slab on grade design calculator. This is a "cloud based computing" site, but I understand the first 14-days are free, but you should verify that first. I believe that the calculator is based on ACI and PCA standards, not on the British Standards.

http://www.cecalc.com/Index.aspx

consider whether the soil is compacted evenly. the slab should have enough re-inforcement to withstand any slab movement, settling, live loads and climate changes.

For any grade slab design, first we have to find the sub grade reaction factor (K) based on the plate load test over the selected surface.

Based on the (K) factor, the subsequent calculation can be done with help of the relevant codes.