Engineering Commons^™

Electrochemical Detection For The Corrosion Of Reinforcing Steel In Concrete During Immersion And Drying Cycles, Bing-Li Jia, Fa-He Cao, An-Na Chen, Jian-Qing Zhang

Journal of Electrochemistry

The corrosion behavior of reinforcing steel in concrete under dry-wet cycle condition has been studied by electrochemical noise(EN) compared with the electrochemical impedance spectroscopy(EIS),SEM micrographs and EDS.The statistical method has been employed to analyze the EN data of reinforcing steel in concrete,which revealed three different corrosion stages of reinforcing steel in concrete,including the dissolution of the passive film,the active corrosion and the cumulation of corrosion product.The wavelet transform has also been employed,which indicated that steel in concrete with pH 1 is associated with uniform corrosion,while steel in concrete with pH 3 and pH 7 are associated with localized corrosion,such as …

Risk-Based Seismic Design Optimization Of Steel Building Systems With Passive Damping Devices, Junshan Liu

Dissertations (1934 -)

Nonlinear time history analysis software and an optimization algorithm for automating design of steel frame buildings with and without supplemental passive damping systems using the risk- or performance-based seismic design philosophy are developed in this dissertation. The software package developed is suitable for conducting dynamic analysis of 2D steel framed structures modeled as shear buildings with linear/nonlinear viscous and viscoelastic dampers. Both single degree of freedom (SDOF) and multiple degree of freedom (multistory or MDOF) shear-building systems are considered to validate the nonlinear analysis engine developed. The response of both un-damped and damped structures using the 1940 EI Centro (Imperial …

Fatigue Strength Of Steel Bridge Members With Intersecting Welds, David T. Delong, Mark D. Bowman

JTRP Technical Reports

The brittle fracture of the Hoan Bridge in December 2000 highlighted the fracture susceptibility of details containing intersecting welds in steel bridges. Though it is now known that details with intersecting welds should be avoided, many existing bridges in Indiana contain details with intersecting welds. Little experimental data on the fatigue performance of these details exists.

The purpose of this study was to evaluate the fatigue strength of several details commonly found in steel bridges in Indiana that contain intersecting welds. Large-scale experimental fatigue testing were performed using nine steel beams to study the behavior of three basic types of …

A Study Of The Continous Cooling Behaviour And Effect Of Preheat And Interpass Temperature On The Haz Of High Strength Quenched And Tempered Steel, Lenka Kuzmikova, Mark Callaghan, Nathan Larkin, Robert Scott, Robert De Jong, Huijun Li, John Norrish

Faculty of Engineering - Papers (Archive)

In this study, the continuous cooling phase transformation behaviour of a quenched and tempered armour steel was investigated. A continuous cooling transformation diagram was constructed providing valuable information for predicting microstructural evolution and mechanical properties at different cooling rates during actual welding fabrication. Welding trials were carried out utilising flux-cored arc welding technique in combination with an austenitic stainless steel consumable. The effect of various preheat and interpass temperatures on cooling rate and consequently on the heat affected zone microstructure and mechanical properties of multipass welds were investigated.

Mechanical, Microstructure And Texture Properties Of Interstitial-Free Steel And Copper Subjected To Equal Channel Angular Extrusion And Cold-Rolling, A A. Gazder, S S. Hazra, C F. Gu, W Q. Cao, C H J Davies, E V. Pereloma

Faculty of Engineering - Papers (Archive)

Interstitial-free steel and OFHC copper were subjected to 8 passes, route B_C room temperature ECAE followed by cold-rolling up to 97.5% thickness reduction. Uniaxial tensile tests and Electron Back-Scattering Diffraction were used to characterise the evolution in mechanical properties, microstructure refinement and micro-texture. IF-steel showed continuous increase in strength whereas Cu returned reduced strength and a small gain in ductility at 97.5% reduction. In both metals substructure refinement was accompanied by an increase in high-angle boundary fraction, average misorientation and a slight increase in Σ3 boundaries. An evolution of crystallographic orientations from negative shear to predominantly cold-rolled textures after …

Role Of Microstructure In Susceptibility Of X70 Pipeline Steel To Hydrogen Embrittlement, Daniel Hejazi, Ayesha J. Haq, Nima Yazdipour, Druce P. Dunne, F Barbaro, E V. Pereloma

Faculty of Engineering - Papers (Archive)

In order to investigate the susceptibility of steels to hydrogen embrittlement as a function of their microstructure X70 steel was chosen in different conditions: normalized transfer bar, as-received hot rolled strip and heat affected zone (HAZ). Notched and fatigue pre-cracked samples were subjected to electrochemical hydrogen charging to achieve 2 ppm hydrogen content. Three point bend tests were conducted on as-received and hydrogen charged samples. The results showed that HAZ samples are more susceptible to hydrogen embrittlement than the others. This was supported by fracture surface observations.