Rehabilitation of earthquake damaged external RC beam‐column joints by joint enlargement using prestressed steel angles

Abstract

Summary The effectiveness of a rehabilitation method based on joint enlargement using prestressed steel angles to enhance the seismic behavior of damaged external reinforced concrete beam‐column joints was experimentally investigated. Three half‐scale joints having either non‐seismic or seismic reinforcement details were tested both before and after rehabilitation by applying lateral cyclic loading of increasing amplitudes. Two defects were considered for the two non‐seismic units, being the absence of transverse steel hoops and insufficient bond capacity of beam bottom steel reinforcing bars in the joint panel zone. The damaged specimens were rehabilitated by injecting epoxy grout into existing cracks and installing stiffened steel angles at the re‐entrant corners of the beam‐column joint, both above and below the beam, that were mounted and held in place using prestressed high‐tensile strength bars. The test results indicated that the seismic performance of the rehabilitated specimens in terms of strength, stiffness, and ductility was fully recovered and comparable with the performance of the seismically detailed specimen. Copyright © 2016 John Wiley & Sons, Ltd.

Strengthening of Columns with Different Innovative Composite Materials for RC Buildings without Sufficient Earthquake Resistance

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“…Although positive results were obtained in terms of bearing power, the difficulties caused a decrease in the use of the sheathing, such as the difficulties experienced in the formwork, reinforcement and concrete works, the inability to use the framework when reinforcing the building, deteriorating the building's architecture, etc. Instead, reinforcing structural elements against shear and bending forces with steel elements came into prominence [7][8][9]. Risks, costs, and architectural issues caused by adverse environmental impacts, unqualified workmanship, fire, or corrosion were met in this reinforcement process.…”

Influence of Precast Member Corbels on Seismic Performance of Precast Beam‐Slab‐Column Joints

“…Priestley [13][14][15] studied the seismic performance of precast concrete frame buildings, beam-column joints, and shear walls and put forward several design suggestions. Shafaei et al [16,17] studied the seismic performance of beam-column joints having either nonseismic or seismic reinforcement details, and the results indicated that rehabilitated methods can recover the mechanical properties. Elsanadedy [18] attempted to develop new precast moment connections for increasing the progressive collapse robustness of precast buildings.…”

Design parameters and material‐scale damage evolution of seismic upgraded RC frames by viscoelastic haunch bracing‐dampers

“…They are verified through experiments and numerical calculations that these seismic strengthening strategies are very effective in improving the seismic performance of structures. Other researchers focus on the use of different types of buckling‐restrained braces, 13–15 RC and steel jackets, 16–18 ferrocement jackets, 19–21 steel and aluminum shear panels, 22–24 steel prop and curb, 25,26 diagonal haunch, 27,28 shape memory alloy, 29–31 prestressed steel angles, 32–34 isolation devices, 35 and metal plate shear walls 36 for the upgrade and modification of RC frame structures. And they are also verified by experiments and numerical calculations that these seismic upgrading strategies are very effective in improving the seismic performance of structures.…”