Three layer theory of  

Thank you so much for your appreciation and encouragement.

Thanks a lot. Good to see your comment.

Thanks a lot. Please share with your friends also

Thank you so much.

You can make yourself. It is very simple. Put two steel rods on a wooden bed at a clear distance of 1.8 times the average of two sizes.

@@SatishIITR thank you sir for your reply yes we can make it But I want to know why this is not available on the length gauge and even this is not specified in IS code.

No, they are likely to be different as IIT PAVE is a GA based program. I shall try a video on this topic soon

@@SatishIITR okay sir. Thank you sir.