Design Provisions for Stair Slabs in the Bangladesh Building Code

This paper deals with the current state of the building code provisions for the structural design of concrete stair slabs in general and those proposed for the Bangladesh National Building Code (BNBC) in particular. The design of stairs has not received due attention in most building codes. As a result, stairs, as they occur with a variety of support conditions, are designed based on the individual designer's judgment. This results in considerable overdesign with some particular types of support arrangements, since their behavior is not readily understood. The recently proposed draft of the Bangladesh National Building Code provides categorical recommendations for the design of different types of stair slabs. Some of these provisions have for the first time been included in a building code. The background of the design provisions as proposed in the BNBC is presented. A critical review of the relevant provisions of BNBC as well as the American, British, and Indian codes of practice are also highlighted in this paper.