**IS 10262: 2009 and IS: 10262: 2019 in concrete mix design:**

This IS provides guidelines for proportioning concrete mixes as per requirements using the concrete materials and the supplementary materials. IS 10262: 2019 is the second revision of the first edition IS 10262: 2009 in concrete mix design in which the following major changes have been made(As per the description of the code):

- The standard was divided into five sections as General, Ordinary and standard grades of concrete, high strength grades of concrete, Self-compacting concrete and Mass concrete.
- A new section for Mix proportioning procedure for High strength concrete for M65 and above(up to target strength of M 100) was included.
- The formula for the target mean strength for mix proportioning for refined by including a new factor based on the grade of the concrete. It was done to ensure a min margin been the characteristic compressive strength and the target mean strength.
- A graph of W/C vs. 28 days strength of concrete introduced for different grades and types of cements for an alternative to initial water-cement ratio assumption.
- In the design of normal concrete mix proportion, the consideration of air content was reintroduced.