Which of the following factors affects the span limit of a reinforced concrete beam?

The span limit of a reinforced concrete beam is significantly influenced by the beam's depth. A deeper beam can typically span a greater distance because it has a higher moment of inertia, which increases its resistance to bending. This means that when loads are applied to the beam, a deeper cross-section can carry those loads without excessive deflection or failure, thus allowing for longer spans.

While other factors like the material properties, environmental conditions, and the weight of the beam may play roles in the overall design and performance of a beam, it is the depth of the beam that most directly addresses its capacity to span distances effectively under load. A deeper beam reduces both deflection and stress, contributing to overall stability and safety in structural design. Therefore, understanding the relationship between beam depth and spanning capability is crucial for engineers in reinforced concrete design.