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Full-Text Articles in Engineering
Extending The Service-Life Of Bridges Using Sustainable And Resilient Abutment Systems: An Experimental Approach To Electrochemical Characterization Of Lightweight Mechanically Stabilized Earth, Fariborz M. Tehrani, Kenneth L. Fishman, Farmehr M. Dehkordi
Extending The Service-Life Of Bridges Using Sustainable And Resilient Abutment Systems: An Experimental Approach To Electrochemical Characterization Of Lightweight Mechanically Stabilized Earth, Fariborz M. Tehrani, Kenneth L. Fishman, Farmehr M. Dehkordi
Mineta Transportation Institute
Bridges are critical components of transportation infrastructure. This research addresses the need to extend the service life of bridges by improving the safety and reliability of bridge abutments and reducing their life-cycle cost and footprints. Mechanically stabilized earth (MSE) is a known strategy to enhance the economy and performance of bridge abutments. In addition, the application of rotary-kiln-manufactured lightweight aggregate backfills improves the performance of MSE bridge abutments with a leaner structural system. Such improvements include a reduction of structural demands due to a lower density, free drainage of granular materials, a high internal friction angle, less settlement with no …
Periodic Deprivation Of Gaseous Hydrogen Sulfide Affects The Activity Of The Concrete Corrosion Layer In Sewers, Xiaoyan Sun, Guangming Jiang, Philip Bond, Jurg Keller
Periodic Deprivation Of Gaseous Hydrogen Sulfide Affects The Activity Of The Concrete Corrosion Layer In Sewers, Xiaoyan Sun, Guangming Jiang, Philip Bond, Jurg Keller
Faculty of Engineering and Information Sciences - Papers: Part B
Sulfide induced concrete corrosion significantly reduces the service life of the sewer systems. Gaseoushydrogen sulfide (H2S) levels are a key factor affecting the corrosion rate and thesefluctuate due to thediurnalflow pattern of sewers. Currently, there is little known about how suchfluctuations, in particularthe periodic deprivation of H2S, may affect the corrosion activity. This study investigated the impact ofthe deprivation of H2S on the sulfide uptake rate (SUR) of concrete coupons incubated in laboratorycorrosion chambers. After systematic evaluation of the gaseous H2S concentration profiles of two sewersystems, two types of profiles, i.e. short- (1 h) and long- (12 h) term deprivation …
The Rapid Chemically Induced Corrosion Of Concrete Sewers At High H2s Concentration, Xuan Li, Liza O'Moore, Yarong Song, Philp Bond, Zhiguo Yuan, Simeon Wilkie, Lucija Hanzic, Guangming Jiang
The Rapid Chemically Induced Corrosion Of Concrete Sewers At High H2s Concentration, Xuan Li, Liza O'Moore, Yarong Song, Philp Bond, Zhiguo Yuan, Simeon Wilkie, Lucija Hanzic, Guangming Jiang
Faculty of Engineering and Information Sciences - Papers: Part B
Concrete corrosion in sewers is primarily caused by H2S in sewer atmosphere. H2S concentration can vary from several ppm to hundreds of ppm in real sewers. Our understanding of sewer corrosion has increased dramatically in recent years, however, there is limited knowledge of the concrete corrosion at high H2S levels. This study examined the corrosion development in sewers with high H2S concentrations. Fresh concrete coupons, manufactured according to sewer pipe standards, were exposed to corrosive conditions in a pilot-scale gravity sewer system with gaseous H2S at 1100 ± 100 ppm. The corrosion process was continuously monitored by measuring the surface …
Assessing Corrosivity Of Galvanized Soil Reinforcements From Electrochemical Tests, Diana Alejandra Cabrera
Assessing Corrosivity Of Galvanized Soil Reinforcements From Electrochemical Tests, Diana Alejandra Cabrera
Open Access Theses & Dissertations
The accurate estimation of the service lives of mechanically stabilized earth (MSE) walls requires a proper evaluation of the corrosion potential through electrochemical test methods. Robust field tests are required to assess the corrosivity of galvanized metal used in MSE walls. To simulate an environment similar to an MSE wall, cylindrical soil specimens about 12 in. (300 mm) in diameter and 10 in. (250 mm) in height were constructed. For every specimen, two instruments were used. The first instrument measured the polarization resistance corrosion tests carried out on galvanized strips and meshes, as well as epoxy-coated rebars. The second instrument …
Correlation Between Zn-Rich Phase And Corrosion/Oxidation Behavior Of Sn-8zn-3bi Alloy, Xin Zhang, Chong Li, Zhiming Gao, Yongchang Liu, Zongqing Ma, Liming Yu, Hui Jun Li
Correlation Between Zn-Rich Phase And Corrosion/Oxidation Behavior Of Sn-8zn-3bi Alloy, Xin Zhang, Chong Li, Zhiming Gao, Yongchang Liu, Zongqing Ma, Liming Yu, Hui Jun Li
Faculty of Engineering and Information Sciences - Papers: Part A
The microstructure of Sn-8Zn-3Bi alloy was refined by increasing the solidification rate and the correlation between Zn-rich phase and the corrosion/oxidation behavior of the alloy was investigated. The Zn-rich phase transforms from coarse flakes to fine needles dispersed in the β-Sn matrix with the increase of the cooling rate. The transformation of Zn-rich precipitates enhances the anticorrosive ability of Sn-8Zn-3Bi alloy in 3.5 wt.% NaCl solution. On the contrary, Sn-8Zn-3Bi alloy with a fine needle-like Zn-rich phase shows poor oxidation resistance under air atmosphere, due to the fast diffusion of Zn atoms in Sn matrix.
Thermodynamic Considerations Of The Corrosion Of Nickel Ferrite Refractory By Na3alf6-Alf3-Caf2-Al 2o3 Bath, Raymond Longbottom, Sharon Nightingale, Brian Monaghan
Thermodynamic Considerations Of The Corrosion Of Nickel Ferrite Refractory By Na3alf6-Alf3-Caf2-Al 2o3 Bath, Raymond Longbottom, Sharon Nightingale, Brian Monaghan
Brian Monaghan
Thermodynamic analysis was carried out to interpret the results of corrosion testing of nickel ferrite samples in cryolite-based baths. The equilibrium between cryolite-based baths and nickel ferrite was considered. Isopleths between cryolite-based baths and nickel ferrite confirmed that for the temperature range of interest (1223-1273 K) there was limited solubility of nickel ferrite in the bath. To better understand the formation of the metal from nickel ferrite, the effect of reducing potentials on nickel ferrite and nickel ferrite-cryolite-based bath systems were considered. The formation of a metal phase was predicted at relatively high pO2. The metal phase was nickel-rich at …
Thermodynamic Considerations Of The Corrosion Of Nickel Ferrite Refractory By Na3alf6-Alf3-Caf2-Al 2o3 Bath, Raymond Longbottom, Sharon Nightingale, Brian Monaghan
Thermodynamic Considerations Of The Corrosion Of Nickel Ferrite Refractory By Na3alf6-Alf3-Caf2-Al 2o3 Bath, Raymond Longbottom, Sharon Nightingale, Brian Monaghan
Faculty of Engineering and Information Sciences - Papers: Part A
Thermodynamic analysis was carried out to interpret the results of corrosion testing of nickel ferrite samples in cryolite-based baths. The equilibrium between cryolite-based baths and nickel ferrite was considered. Isopleths between cryolite-based baths and nickel ferrite confirmed that for the temperature range of interest (1223-1273 K) there was limited solubility of nickel ferrite in the bath. To better understand the formation of the metal from nickel ferrite, the effect of reducing potentials on nickel ferrite and nickel ferrite-cryolite-based bath systems were considered. The formation of a metal phase was predicted at relatively high pO2. The metal phase was nickel-rich at …
Influence Of Fluoride And Chromium(Vi) Ions On Corrosion Mechanisms Of Pb-3wt%Sn-0.5wt%Ag Anode, Jianzhong Li, Xiuli Sun, Yanwen Tian, Yue Zhao
Influence Of Fluoride And Chromium(Vi) Ions On Corrosion Mechanisms Of Pb-3wt%Sn-0.5wt%Ag Anode, Jianzhong Li, Xiuli Sun, Yanwen Tian, Yue Zhao
Faculty of Engineering and Information Sciences - Papers: Part A
A mix solution of fluorine and chromium ions (Cr-F solution) for applications in chromium plating field has a characteristic of strong corrosion and oxidation, promoting lead alloys anode degraded rapidly. The present study explores the time dependence on corrosion mechanisms of lead alloys anode oxidised in Cr-F solution under conditions of high current density. Scanning electron microscopy (SEM) with an energy dispersive X-ray spectroscopy (EDX) shows a double-layer oxide film is electrochemically developed on lead alloys anode after oxidation for above 0.5h. The outer layer is primarily PbO and PbO2, and the inner layer contains PbCrO4 and PbF2, followed by …
Laboratory Study On Rockbolt Corrosion, Naj Aziz, P Craig, Jan Nemcik
Laboratory Study On Rockbolt Corrosion, Naj Aziz, P Craig, Jan Nemcik
Faculty of Engineering and Information Sciences - Papers: Part A
The effect of long term exposure of full size bolts to corrosive environments is presented. A special test rig was used to test four bolts under different loading conditions. Four, X-grade identical corrosioin testing using acid sulphate water. the pH value of the curculated water varied between 3.4 and 4.3. The corrosion exposure test period lasted three and half years. Two bolts were axially loaded to 10 and 20 tonnes force respectively, the third bolt was subjected to a 360 Nm torsion load and the fourth bolt was left unstressed to act as a reference bolt. After the test period …