RESULTS OF EXPERIMENTAL STUDIES OF REINFORCED CONCRETE BEAMS WITH DAMAGE IN THE PURE BENDING ZONE UNDER A LOAD OF 30% OF THE ULTIMATE CAPACITY

Abstract

This research focuses on reinforced concrete beams that exhibit asymmetric damage when subjected to external loading. The beams were designed and manufactured at a precast concrete plant. Comprehensive design solutions and detailed working drawings of the specimens are provided, showing the exact dimensions and reinforcement arrangements. The experimental setup is depicted, illustrating the placement of all measurement instruments, supports, and loading points. Strains of compressed concrete zone and tensile reinforcement were measured using high-precision dial gauges with a resolution of 0.001 mm, while three additional dial indicators with a resolution of 0.01 mm recorded support displacements and settlements. The experimental protocol followed a structured methodology to study the behavior of beams with partial damage. Damage was applied at a load corresponding to 30% of the beam’s ultimate capacity. The dimensions of the damage were as follows: width 200 mm, height 100 mm, and depth 30 mm, chosen to realistic structural defects. The influence of the introduced damage on the beams’ load-bearing performance was examined, including vertical and horizontal deflections and the evolution of strains in both the reinforcement and the compressed concrete zone. Experimental observations revealed that after the reinforcement reached its yield point, the beams continued to deform mainly through plastic elongation in the tensile region and increased compression in the concrete. These results provide critical insights into the response of reinforced concrete members with damage. Furthermore, the findings enhance understanding of deformation localization in beams with asymmetric damage, which is essential for predicting structural performance and ensuring safety under actual service conditions.