Thesis (Ph. D.)--Drexel University, 2006. / Includes abstract and vita. Includes bibliographical references (leaves 165-174).

Thesis (M.S. in Engineering)--University of Texas at Austin, 2006. / Includes bibliographical references.

Thesis (M.S.)--Oregon State University, 2008. / Printout. Includes bibliographical references. Also available on the World Wide Web.

Thesis (Ph. D.)--University of Washington, 2006. / Vita. Includes bibliographical references (leaves 190-192).

Thesis (Ph. D.)--University of Washington, 2000. / Vita. Includes bibliographical references (leaves 241-244).

No description available.

The Florida Department of Transportation (FDOT) has been using supplementary cementitious materials while constructing steel reinforced concrete marine bridge structures for over three decades. It has been found from previous studies that such additions in concrete mix makes the concrete more durable. This research was conducted to better understand the corrosion propagation stage of steel rebar embedded in high performance concrete exposed to high humidity environment. Reinforced concrete samples that were made with binary mixes, and ternary mixes were considered. None of these concretes had any admixed chloride to start with. An accelerated chloride transport method was used to drive chloride ions into the concrete so that chlorides reached and exceed the chloride threshold at the rebar surface and hence the corrosion process initiated after a short period of time (within few days to few months). Once corrosion has initiated the corrosion propagation can be studied. Electrochemical measurements such as rebar potential measurements, Linear Polarization Resistance (LPR), Electrochemical Impedance Spectroscopy (EIS), and Galvanostatic Pulse (GP) measurements were taken at regular intervals (during and after the electro-migration process) to observe the corrosion propagation in each sample. During the propagation stage, reinforcement eventually reached negative potentials values (i.e., Ecorr≤ –0.200 Vsce) for all the samples. The corrected polarization resistance (Rc) was calculated by subtracting the concrete solution resistance from the apparent polarization resistance measured. The Rc values obtained from LPR and GP measurements were converted to corrosion current (as the corroding area is unknown), and these corrosion current values measured over time were used to obtain the calculated mass loss (using Faraday’s Law). A comparison was made of the calculated corrosion current obtained using the LPR and GP tests. A comparison of mass loss was also obtained from the values measured from LPR and GP tests. From the experimental results, it was observed that the corrosion current values were largely dependent on the length of solution reservoirs. For specimens cast with single rebar as well as three rebars, the most recent corrosion current values (measurements taken between July 2018 to October 2020) in general were larger for the rebars that are embedded in specimens prepared with SL mix, followed by specimens prepared with FA, T1, and T2 mixes respectively. The range of corrosion current values (most recent) were 0.8-33.8 μA for SL samples, 0.5-22.5 μA for FA samples, 0.8-14.8 μA for T1 samples, and 0.7-10.4 μA for T2 samples respectively. It was also found that the calculated mass loss values were larger for rebars that are embedded in specimens (single rebar and three rebars) prepared with SL mix, followed by specimens prepared with FA, T1, and T2 mixes respectively. The range of calculated mass loss values were 0.07-1.13 grams for SL samples, 0.06-0.62 grams for FA samples, 0.12-0.54 grams for T1 samples, and 0.06-0.40 grams for T2 samples respectively. A variety of corrosion related parameters (Ecorr, Rs, Rc, and Icorr) and calculated theoretical mass loss values observed, were due to the changing parameters such as concrete compositions, concrete cover thickness, rebar diameter, total ampere-hour applied, and reservoir size. The specimens showed no visual signs of corrosion such as cracks or corrosion products that reached the concrete surface. The actual size of the corroding sites was unknown as the specimens were not terminated for forensic analysis. The size of the corroding sites could affect how much corrosion products are required to crack the concrete. It is speculated that the corrosion products in liquid form penetrated the pore structure but did not build up enough to cause cracks. No cracks or corrosion bleed outs were observed within the monitored propagation period of approximately 1600 days. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2020. / FAU Electronic Theses and Dissertations Collection

No description available.

Waterproofing membranes have been used on bridge decks for almost three decades in order to prevent chloride ingress into concrete. However, the performance of these membranes have yet to be adequately evaluated. Therefore, this research was carried out primarily to evaluate the integrity and effectiveness of standard preformed membranes placed on concrete bridge decks. The actual conditions of a bridge deck were simulated in the laboratory using scaled-down reinforced concrete specimens. Forty-eight outdoor and twelve indoor specimens were cast. Three types of standard preformed membranes (Bithuthene 5000, Royston lOA, and Protecto Wrap M400-A), punctured with holes of various sizes and frequencies per unit area, were placed on the specimens. All of the specimens were overlaid with 2.5 inches of hot-mix asphalt, except four outdoor (control) specimens and three indoor specimens. / Master of Science

A one-tenth scale model of a skewed reinforced concrete rigid frame bridge was constructed and tested both within the elastic range and to ultimate load. The model was fabricated of reinforced concrete using a 1: 3.8 : 0 mix and 1/8 inch deformed reinforcing bars. A total of 57 SR-4 type AR-7 rosette gages were used to measure the strains on the surface of the concrete at selected positions. An additional 108 SR-4 type AR-7 and AR-7-4 strain gages were fastened to the steel reinforcing. Deflections were measured at 11 points of the deck and supporting reactions determined by suitable dynamometers. The vast amount of strain data was presented in tables. Part of it was converted into stresses and these integrated to find the internal reactive forces and moments at selected sections. However, the unknown behavior of concrete in biaxial tension and difficulty in establishing the precise position of the neutral surface prevented as close a check of static equilibrium as would have been desirable. / Master of Science