Engineering Commons^™

Chloride Contamination Remediation On Steel Bridges, Bobby W. Meade, Christopher Goff, Sudhir Palle, Theodore Hopwood Ii

Kentucky Transportation Center Research Report

Researchers evaluated 32 steel surface preparation methods to determine how effectively they remove chloride from corroded chloride-contaminated steel panels. Wet methods proved more effective than dry methods. The three most effective wet methods injected mineral slag abrasives in a water stream and resulted in less than 1% chlorides remaining. Most dry surface preparation methods left significantly more chloride contamination after surface preparation. The three most effective dry methods used multiple blast cleaning cycles. These methods approached the effectiveness of the best wet methods, with 1.6 to 2.0% chlorides remaining. The least effective surface preparation was a single abrasive blast cleaning …

Evaluation Of The Use Of Painted And Unpainted Weathering Steel On Bridges, Theodore Hopwood Ii, Sudhir Palle, Bobby W. Meade, Rick Younce

Kentucky Transportation Center Research Report

KTC researchers studied the use of unpainted weathering steel on bridges, using findings of inspections performed on Kentucky Transportation Cabinet (KYTC) bridges constructed with both painted and unpainted weathering steel as well as laboratory testing. Laboratory tests were conducted on test panels of conventional and weathering grades of steel to determine the performance of barrier and zinc-based coatings over abrasive-blasted substrates of those steel types in both the new and corroded conditions. The report provides the following recommendations for the use of painted and unpainted weathering steel on Kentucky bridges based upon both the field and laboratory findings:

• KYTC should …

Performance Assessment Of Deteriorated And Retrofitted Steel Hp Piles, Steven T. Stauffer

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Deterioration of aging bridges can be attributed to an assortment of mechanisms throughout the structure, with remediation policies also varying. This study focused on assessing the validity of the Nebraska Department of Roads’ (NDOR) reinforced concrete encasement retrofit for corroded steel HP piles. Experiments were designed and conducted to test the capacity of the NDOR retrofit and evaluate failure limit states. Two pile locations were considered: abutment and pile bent. For each location there was a non-deteriorated, deteriorated, and retrofitted case. These cases represented the pile at key stages during its life. NDOR’s concrete encasement retrofit provided the required stability …

On The Role Of The Pore Water Chemistry Of Deficient Post-Tension Grout To Promote Steel Corrosion, Samanbar Permeh

FIU Electronic Theses and Dissertations

Corrosion failure of post-tension tendons with pre-packaged thixotropic grout was documented in Florida Bridges in less than 10 years of service. Analysis of deficient grout in Florida post-tensioned (PT) bridges where severe corrosion developed indicated enhanced sulfate ion concentration, high pore water pH, enhanced moisture and low chloride content. The corrosion wasn’t consistent with the conventional causes of steel corrosion such as bleed water accumulation in grout void spaces, chloride contamination and pore water carbonation. Corrosion development was associated with deficient grout with enhanced sulfate levels. However, limited information is available on the corrosion behavior of PT strand in grout …

Probability-Based Hurricane Resilience Evaluation And Retrofitting For Residential Community, Yadong Dong

Dissertations, Master's Theses and Master's Reports

Wood residential construction is vulnerable to hurricanes, as evident in recent hurricane events. Many studies indicated that the changing climate may very likely alter hurricane patterns, which could lead to more severe hurricane damage to the wood residential construction that accounts for 90% of the residence in the USA. On the other hand, deterioration of material increases the chance of structural failure by reducing the structural capacity (e.g., corrosion of fasteners in roof panel could significantly reduce the withdrawal capacity of the roofing structure during hurricane events).

Currently, most hurricane damage estimations only focus on direct loss (e.g., structural loss). …