2.3. Concrete Beams
The usage of Conventional reinforced concrete members for a long span is possible, but they become overly large and bulky. As comparison to regular reinforced concrete, pre-stressed concrete has more effective, smaller, and lighter cross sections that experience fewer cracks than standard reinforced concrete.

Precast, pre-stressed concrete members are available in standard shapes and sizes. The two most commonly used shapes are the single-tee and double-tee. Double tees are commonly used for spans up to 21 m while single tees are used for spans up to 30 m or more.
