Assessment of a cracked reinforced concrete beam: Case study

This paper presents the analysis and repair of a cracked reinforced concrete beam in a 3-story office building in Riyadh, KSA during its construction and near completion. In October 2015, a reinforced concrete beam with a cross section of 300 mm x 1500 mm and a clear span of 16.5 m in this building cracked at the connection with one of its supporting columns. This crack propagated on both sides of the beam. To investigate the main reason of the beam cracking, a site visit was conducted to visually inspect the cracking beam and the connecting structural elements. After that a detailed analysis of the beam using PLAXIS and SAP2000 to investigate the stresses developed in the beam, spot the most stressed parts and to check the adequacy of the design. The analysis revealed the inadequacy of flexural resistance of the beam as well as the shear and torsion capacity. The main reason of the crack is underestimating the cladding weight. Based on the results, a repair methodology was selected using CFRP sheets to increase the flexural capacity of the beam section with enhancement to its torsional and shear carrying capacity to meet the design demand.