Difference between Beam and Arch Today we are discussing the Difference between Beam and Arch. This Is the topic of civil engineering. ARCH CURVED SHAPED. HAVE MORE STRENGTH THAN BEAM or a curved symmetrical structure spanning an opening and typically supporting the weight of a bridge, roof, or wall above it. BEAM STRAIGHT SHAPE.LESS STRENGTH THAN ARCH or a long, sturdy piece of squared timber or metal used to support the roof or floor of a building. Difference A curved beam can be an arch but an arch is not necessarily made from a curved beam . An arch can be fabricated from many materials. One form of an arch is a gravity arch where properly shaped stones or blocks are correctly shaped and laid so gravity holds the arch in place. The structural behavior of a beam is in a state of equilibrium if the constraints permit no rigid body movement upon the application of loads. Whereas an arch may be looked upon as a curved girder, either a solid rib or braced supported at it