Effect of Span, Load Intensity, and Beam Geometry on Stress and Deflection Behavior of RCC Beams

Abstract

This study investigates the influence of variations in beam geometry, span, load intensity, and permissible stresses on the structural behavior of reinforced concrete beams. Using classical bending and shear stress formulations, the effects of a 20% increase in key parameters were analytically evaluated. Results indicate that a 20% increase in beam span leads to a proportional 20% increase in beam depth, whereas a 20% increase in beam width or permissible compressive stress in bending results in an 8.68% reduction in beam depth. Shear stress analysis shows that an increase in load intensity of 20% raises shear stress by approximately 9.48%, while changes in span have no effect on shear stress. Increasing beam width reduces shear stress by about 8.90%, whereas higher permissible compressive stress indirectly increases shear stress due to reduced beam depth. Compressive stress at the column increases by nearly 19.85% with a 20% rise in load intensity and must remain within permissible limits. Flexural stress increases proportionally with load intensity and rises significantly (44%) with increased span for a given beam depth, while greater beam width reduces flexural stress. Tensile stress, governed by the total load and cross-sectional area, increases linearly with load intensity but decreases with increased beam width and depth. The study also highlights the interrelation between stress development and deflection, emphasizing the importance of optimized beam dimensions to ensure structural safety and serviceability under varying loading and geometric conditions.