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

Title:	Performance improvement of concrete-filled steel composite (CFSC) square and rectangular columns
Authors:	Bahrami Alireza (P54547)
Supervisor:	Hamidon Wan Badaruzzaman Prof. Ir. Dr. Wan
Keywords:	Steel composite Composite construction
Issue Date:	18-Feb-2013
Description:	Concrete-filled steel composite (CFSC) columns which consist of concrete inside the perimeter steel have been increasingly used in modern structural engineering projects owing to their structural advantages over traditional steel and reinforced concrete columns. Circular CFSC columns possess better performance than their square and rectangular counterparts because of more confinement effect provided by the steel wall for the concrete core in the former columns compared to the latter ones. Therefore, this study focuses on the square and rectangular CFSC slender and stub columns to improve their performance as the main objective of this thesis. The finite element software LUSAS is used in the present thesis. Three-dimensional (3D) nonlinear finite element models are verified by comparing the results from the nonlinear analyses with those from the corresponding experimental tests. Modelling verifications completely reveal that the proposed 3D nonlinear finite element modelling can accurately predict the structural performance of the columns. CFSC slender and stub columns are extensively improved in this research work by using various stiffening methods for the columns (a maximum ultimate load capacity increase of 37% for the slender columns and maximum ultimate load capacity and ductility enhancements of 17.9% and 25.5% respectively for the stub columns) and their structural performance is also examined by doing vast parametric studies on the columns. Results obtained from the nonlinear finite element analyses of the CFSC slender columns are compared with predictions by the design code EC4. An equation is proposed on the basis of the obtained results from the nonlinear analyses of the CFSC stub columns to predict their ultimate load capacity values. Comparisons of the finite element results with those from the suggested equation of other researchers, the proposed equation of the present study, and EC4 uncover that the proposed equation of this study can predict the ultimate load capacity of the CFSC stub columns with better accuracy (0.3% underestimation) compared to EC4 (4.6% underestimation). Also, tapered composite columns are widely assessed in this thesis. Special tapered concrete-filled steel composite (TCFSC) slender columns are formed in the current study. These special TCFSC slender columns are made by the enhancement of the mid-height depth and width of CFSC slender columns. In other words, a special tapered angle is adopted in this research which is increased from the bottom and the top of the tapered composite columns to their mid-height and forms TCFSC slender columns that is completely different from the common tapered angle (from the bottom to the top) in tapered composite columns. Therefore, CFSC slender columns are numerously improved in the present thesis by the use of this special tapered angle as well (ultimate load capacity increases up to 56.7%). Moreover, structural performance of these improved TCFSC slender columns is investigated through conducting vast parametric studies on the columns. It is concluded that the parameters adopted in the extensive parametric studies on the CFSC and TCFSC columns in this research work affect the structural performance of the columns and the improved columns of this study behave better than their companion traditional ones.,Ph.D
Pages:	303
Call Number:	TA492.C7B337 2013
Publisher:	UKM, Bangi
Appears in Collections:	Faculty of Engineering and Built Environment / Fakulti Kejuruteraan dan Alam Bina

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