Pre-stressed concrete is an ideal material for beam bridge construction; the concrete withstands the forces of compression well and the steel rods imbedded within resist the forces of tension.

The photograph illustrates the shape change of elements of a beam in bending. Note that the material is in compression on the inside of the curve and tension on the outside of the curve, and that ...

Traditional construction relies on people operating heavy machinery to place steel ... or tension, on buildings. "The ...