All structural materials for reinforced concrete and the standard acceptance tests for such materials are prescribed under the ACI (American Concrete Institute) Code which is a leading authority for inspection, project management and consulting for individuals and organizations involved in construction and concrete design. The ACI revises its specifications from time to time to facilitate improvements in production methods, materials, and testing. Beam and girder are the two frequently used codes in structural systems, specifically in the 1995 ACI Code. Both are subjected to flexural loads and act as a primary part of the structural framing system. Both are horizontal members and among the most commonly designed elements of the structure. Both the terms are often used interchangeably but certain factors distinguish one from the other. Understanding the difference between the two is crucial to the construction scene.
What is a Beam?
A beam is a primary part of a structural framing system specially designed to carry distributed loads such as parallel walls or roof systems. Beams are one of the most commonly designed elements of structure in engineering intended to resist loads and its primary mode of deflection is bending. It is mainly used for resisting bending moments, vertical loads, and shear forces. Thus, beams are defined by their bending moments which are calculated for the primary requirements for building a structure. In simple terms, any horizontal structural member which undergoes lateral load and is capable of withstanding load is a beam.
What is Girder?
Girder is basically a beam which supports other smaller beams and acts as the main horizontal support of a structure. Unlike beams, girders are designed to support major concentrated loads such as columns or beam reactions and their load-bearing capacity is much greater than beams. It can be made from a variety of construction materials such as concrete, stainless steel, or a combination of both. It supports vertical loads and may consist of a single piece or more than one piece bound together.
Difference between Beam and Girder