Engineering Commons^™

Widening Of Reinforced Concrete Bridges – Extension Of Pier Cap Beams With Cfrp Composites, Cheng Tan

Dissertations - ALL

Increase in traffic load dictates widening highway bridges rather than construction of new bridges, as it offers an economical solution. Highway bridge widening is usually accomplished by the construction of additional new bridge piers, however, large amount of construction work and extensive use of heavy plant and machinery could result in very high cost. For limited widening of bridges, e.g. addition of one driving/emergency lane, extension of the pier cap beam offers an attractive solution. Due to additional load resulting from the widened bridge, strengthening of extended cap beams may be needed. In addition, depending on the strength of the …

Strengthening Of Corroded Steel Structures Using Cfrp – An Experimental Review, Ghada El-Mahdy Ph.D., P.Eng, Abdallah H. Yassin, Abdel El Rahman Khaled

Civil Engineering

Fibre reinforced polymers (FRP) have been widely used to strengthen reinforced concrete structures, however, nowadays their use to strengthen steel structures is under investigation. In particular, the need to strengthen corroded steel structures found in aggressive environments, such as marine environments, which have undergone a reduction in cross-sectional area and hence a reduction in their load-carrying capacity is in need of studying. The main problems that arise when using carbon fibre reinforced polymer (CFRP) sheets to strengthen steel structures is the weakness in the interfacial bond between the CFRP and the steel surface, the thinness of CFRP sheet, and the …

Effect Of Multi- Steel Bolt Anchorages On Composite Beams, Dawei Zhang, H. F. Shi, W. L. Jin, Tamon Ueda

International Conference on Durability of Concrete Structures

Using fiber-reinforced polymer (FRP) to retrofit or strengthen the concrete structures is an attractive option in construction areas nowadays. However, premature debonding failures limit the efficacy of fiber utilization. It is presently accepted that anchorage system is an attractive option to solve this problem. Much efforts has been made through experimental testing and numerical modeling to investigate the anchorage systems, meanwhile various systems were created and developed. However, researches on the mechanism of the anchorage systems are still too rare to build a countable and union design guideline with respect to different premature debonding failure modes. The present paper focused …

Rapid Retrofit And Strengthening Of Bridge Components, Abheetha Peiris, Issam E. Harik

Kentucky Transportation Center Research Report

Rapid repair of damaged or deteriorated concrete bridge components will prevent the entire bridge from suffering irreversible damage in the future due to gradual spalling of concrete or corrosion of exposed steel. CFRP laminates and fabrics have become popular for repairing and strengthening of concrete girders. A series of CFRP materials — branded CatStrong — specifically designed for the repair and retrofit of bridges was developed at the Kentucky Transportation Center and the University of Kentucky. These materials include the CFRP Rod Panels (CatStrong CRPs), Unidirectional and Triaxial Carbon Fabric (CatStrong UCF and TCF), and Triaxial Carbon Wrap (CatStrong TCW). …

Analysis Of Frp-Wrapped Concrete Piles In Integral Abutment Bridges Subjected To Axial And Cyclic Lateral Loads, Hassan Mohammed Magbool

Theses and Dissertations

ABSTRACT

The long-term maintenance problems associated with expansion joints, which are used to accommodate bridge movements in conventional bridges, have been the primary motivation for the use of integral abutment (jointless) bridges. These bridges rely on the interaction between the structure and the surrounding soil to accommodate bridge movements without the use of any expansion joints on the bridge superstructure. As the bridge superstructure expands and contracts due to seasonal thermal and other strains, relatively large forces can develop in the pile near the pile-cap interface. These reversible moment and shear forces can lead to localized damage near the top …

Propagating, Evanescent, And Complex Wavenumber Guided Waves In High-Performance Composites, Victor Giurgiutiu, Mohammad Faisal Haider

Faculty Publications

The study of propagating, evanescent and complex wavenumbers of guided waves (GWs) in high-performance composites using a stable and robust semi-analytical finite element (SAFE) method is presented. To facilitate understanding of the wavenumber trajectories, an incremental material change study is performed moving gradually from isotropic aluminum alloy to carbon fiber reinforced polymer (CFRP) composites. The SAFE results for an isotropic aluminum alloy plate are compared with the exact analytical solutions, which shows that N = 20 SAFE elements across the thickness provides

Propagating, Evanescent, And Complex Wavenumber Guided Waves In High-Performance Composites, Victor Giurgiutiu, Mohammad Faisal Haider

Faculty Publications

The study of propagating, evanescent and complex wavenumbers of guided waves (GWs) in high-performance composites using a stable and robust semi-analytical finite element (SAFE) method is presented. To facilitate understanding of the wavenumber trajectories, an incremental material change study is performed moving gradually from isotropic aluminum alloy to carbon fiber reinforced polymer (CFRP) composites. The SAFE results for an isotropic aluminum alloy plate are compared with the exact analytical solutions, which shows that N = 20 SAFE elements across the thickness provides <0.5% error in the highest evanescent wavenumber for the given frequency-wavenumber range. The material change study reveals that reducing the transverse and shear moduli moves the wavenumber solution towards one similar to composite material. The comparison of the propagating, evanescent and complex wavenumber trajectories between composites and aluminum alloy show that antisymmetric imaginary Lamb wave modes always exist in composites although they may not exist in isotropic aluminum alloy at some frequencies. The wavenumber trajectories for a unidirectional CFRP plate show that the range of real wavenumber is much smaller than in the isotropic aluminum alloy. For laminated CFRP composite plates (e.g., unidirectional, off-axis, transverse, cross-ply and quasi-isotropic laminates), the quasi Lamb wave and shear horizontal (SH) wave trajectories are also identified and discussed. The imaginary SH wave trajectories in laminated composites are distorted due to the presence of ±45 plies. The convergence study of the SAFE method in various CFRP laminates indicates that sufficient accuracy can always be achieved by increasing the number of SAFE elements. Future work will address the stress-continuity between composite layers.