1. UKM Learning and Research Repository
2. PHD Thesis / Tesis PHD
3. Faculty of Engineering and Built Environment / Fakulti Kejuruteraan dan Alam Bina

Title:	Seismic resistance of strengthened exterior reinforced concrete beam-column joints
Authors:	Saleh Yhyh Saleh Laseima (P81101)
Supervisor:	Azrul A. Mutalib, Assoc. Prof. Dr.
Keywords:	Universiti Kebangsaan Malaysia -- Dissertations Dissertations, Academic -- Malaysia Reinforced concrete Beam-column joints Seismic resistance
Issue Date:	9-Jun-2021
Description:	The exterior reinforced concrete (RC) beam-column joints have long been recognised as the most critical components of existing RC buildings that can be deteriorated severely under earthquakes loading especially buildings that are designed prior to the implementation of seismic design codes. These buildings can undergo progressive collapse resulting in the failure of RC beam-column joints during the earthquake event. Fibre-reinforced polymers (FRP) composites and ferrocement jacket (FJ) have been recognised by researchers as the easiest and most cost-effective strengthening techniques to resist the seismic load. The partially confinement effect, debonding of the FRP composite, the strength of the FJ materials selection, and inappropriate FRP composite and FJ configurations are the difficulties that are still challenging the researchers. Therefore, the main objective of this study is to evaluate the seismic strengthening technique performance and cost-effectiveness for exterior RC beamcolumn joints using carbon fibre reinforced polymer (CFRP), basalt fibre reinforced polymer (BFRP), and FJ. The experimental study was executed to test the full-scale improved strengthened RC beam-column joints, while the numerical study was carried out to analyse other strengthening parameters to obtain the best seismic resistance strengthening technique. In the experimental study, four identical full-scale beamcolumn joints with no joint transverse reinforcement detail were tested under cyclic loading (maximum 500 kN capacity) that simulates the earthquake loading and 261.6 kN of axial load. The experimental specimens consist of unstrengthened RC beamcolumn joint (control) and the other three specimens were strengthened with CFRP, BFRP, and FJ. The strengthening techniques were improved in respect of the bestproposed configurations (with X-shaped, U-shaped, top and bottom column strip and beam strip), increased confinement effect (the cross-section of the beam and column changed from square to squircle segments with an edge radius15 mm) and high strength of tested materials (tensile strength of CFRP and BFRP are 2864 MPa and 1826.5 MPa, respectively, while FJ consists of 374.8 MPa yield strength of wire mesh and 20.8 MPa compressive strength of cement mortar). The finite element (FE) method using ANSYS software was utilised in the numerical study. The numerical models were verified with the experimental results and showed between 80% to 90% accuracy. A total of 110 nonlinear FE models were developed to investigate the effects of strengthening parameters that were not considered experimentally, such as i) varied CFRP, BFRP, and wire mesh layers, ii) different configurations of the CFRP, BFRP, and FJ, iii) strength of steel wire mesh and cement mortar in the FJ, and iv) different column's axial loads. The results of the experimental and the numerical studies revealed that the ultimate strength of CFRP, BFRP, and FJ strengthened specimens were increased respectively by 62%, 56%, 87%. There were also significant increases in dissipated energy by 106%, 136%, and 192%, respectively for CFRP, BFRP, and FJ. The BFRP and FJ-strengthened specimens showed a significant decrease in strengthening cost by 33% and 79%, respectively; less than CFRP. The study successfully presented improved seismic resistance strengthening techniques for deficient RC joints and the strengthening with FJ is an ideal method in terms of performance and cost.,Ph.D.
Pages:	311
Publisher:	UKM, Bangi
Appears in Collections:	Faculty of Engineering and Built Environment / Fakulti Kejuruteraan dan Alam Bina

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.