13.5 : مثال التصميم: توزيع التسليح في المقاطع الخرسانية

Consider a reinforced concrete beam cross-section for which the required reinforcement cross-section equals 4 square inches according to the reinforcement design.

Bars with a 1.693-inch nominal diameter are available in stock.

Now, the engineer has to adjust the bars of available diameter to meet the desired steel cross-sectional area of four square inches.

The cross-sectional area of a 1.693-inch diameter bar is 2.25 square inches, and the number of bars will be 1.777. This number will be rounded off to the nearest whole number, that is 2.

The total cross-sectional area of the 2 bars of diameter 1.693 inches would be equal to 4.5 square inches.

An additional cross-sectional area of 0.5 square inches is provided to meet the desired cross-section with the available bars.

If the available stock has bars of diameter equal to 1.128 inches, then the area of the cross-section of this bar is 1 square inch, which means exactly 4 bars would suffice for the design requirements of the steel cross-section.