Stay-In-Place (SIP) formwork systems are widely used for concrete slabs in industry due to their relative ease and speed of construction. Conventionally, corrugated metal sheets or precast panels are used as formwork. In recent years, the SIP formwork technique has been proposed in conjunction with Fiber Reinforced Polymer (FRP) composites. The resulting system combines the construction advantages of SIP formwork with the durability and corrosion resistance of FRP materials. Bridge decks are a particularly enticing application due to their exposure to harsh environmental conditions and the need for rapid construction to minimize traffic disruptions. This study broadly evaluates FRP SIP formwork for concrete bridge decks both experimentally and numerically. In total, 9 full scale bridge deck sections, 32 small scale decks and more than 40 auxiliary tests were conducted, including the construction and testing of a full bridge at scale. Additionally, a numerical model was developed to predict punching shear failure based on the theory of plates and shells. Experimental testing was conducted on two FRP SIP form configurations, namely flat plates with T-shape stiffeners and corrugated plates, and used a variety of different detailing and geometries. Some of the investigated parameters included the width effect of bridge deck section tests, the effect of deck span, the effect of bond at the FRP-concrete interface, the panel-to-panel splice configuration, concrete strength, and boundary condition at support, including a monolithic connection with precise girders. Results of the study include the determination of a critical aspect ratio for bridge deck sections, optimization of the panel-to-panel splice detail, and an assessment of the in-plane restraint available to interior span bridge decks. The numerical model, based on the Levy solution for loaded plates, produces a flexural response for a variety of bridge deck configurations and geometries. A failure criterion was applied to establish the punching shear capacity. The model was evaluated against experimental results and provided good correlation. It was then used to investigate a variety of FRP plate thicknesses, spans and effective widths for full scale FRP SIP formwork bridge decks. / Thesis (Ph.D, Civil Engineering) -- Queen's University, 2013-10-11 15:55:26.546

Most of the pollution found in highway runoff is both directly and indirectly contributed by vehicles such as cars and trucks. The constituents that contribute the majority of the pollution, such as metals, chemical oxygen demand, oil and grease, are generally deposited on the highways. These can become very harmful and detrimental to human health when they come in contact with our water system. The connecting tie between these harmful highway-made pollution and our water system, which includes our ground waters and surface waters, is rainfall. The main objective of this runoff study was to characterize and assess the quantity and quality of the storm water runoff of a bridge deck that discharged into a receiving water body. The bridge deck and the creek were located in the coastal margin region in the southeast area of Texas on the border of Harris and Galveston counties. Flow-activated water samplers and flow-measuring devices were installed to quantitatively determine the rate of flow of the bridge deck and determine different pollutant loading by sampling the receiving water body (Clear Creek). The collected samples were analyzed for total suspended solids, toxic metals, and other relevant constituents of concerns. The results illustrated that the runoff from the bridge deck exhibited low total suspended solids concentrations (which were highest in the creek). However, other metal constituents like the zinc and cooper concentration were high and above standards. The phosphate concentrations in the creek were the highest and exceeded EPA standards. Several nitrate concentrations were also noticeably above EPA standards.

This research focuses on the creation, validation, automation, and deployment of a nondestructive vertical electrical impedance (VEI) bridge deck assessment apparatus. A multichannel impedance analyzer with a moving platform is developed that can assess the deterioration state of a bridge deck without stationary traffic control. The multichannel apparatus is capable of taking over 500 impedance samples a second and can scan a bridge deck over 500 times faster than more traditional techniques. This research also shows VEI measurements are inversely proportional to the diffusivity of ions through concrete and that an impedance measurement frequency of 25 kHz is the most predictive measurement frequency of diffusivity. Finally, this research demonstrates the utility of VEI measurements by inspecting five asphalt overlaid bridges. VEI measurements were sensitive to defects in membranes and are one of the only nondestructive measurements that provide useful information about the deterioration state of asphalt overlaid bridge decks.

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No description available.

Ground penetrating radar (GPR) technology has been used for the past 20 years for a variety of applications to assess transportation infrastructure. However, the main issue after all these years remains: "How well does GPR work and under what conditions?" Results show that GPR works well for some situations, but is not an appropriate tool for other situations. It is not used currently on a routine basis by the US Departments of Transportation (DOTs) due mainly to difficulties encountered with data interpretation. Data interpretation difficulties are mainly attributed to the fact that images obtained from the reflected signals are not photographs of the features that are beneath the surface being investigated. The images show the amplitude of the radar-reflected signals from the interfaces with different dielectric properties. Therefore, a considerable amount of experience and operator skill may be required to correctly interpret sub-surface radar results. To better understand reflected GPR signals, this research was conducted with the following objectives: to determine the dielectric properties of concrete over the used GPR frequency range; to synthesize the reflected air-coupled radar signals and compare them with measured waveforms; to model and study the effects of simulated defects in concrete on the reflected air-coupled and ground-coupled radar signals; and to validate the research results in the field by predicting layer thicknesses of flexible pavements and detecting moisture in flexible pavement systems. Several concrete slabs, 1.5x1.5 m, were constructed with known thicknesses, simulated defects, and different reinforcement configurations. The concrete mixes included four different bridge deck mixes and one concrete pavement mix used in the State of Virginia. Results have shown that the dielectric constant of concrete is frequency and mix dependent. However, modeling the reflected signals using an average complex dielectric constant over the entire radar frequency range led to modeled waveforms comparable to the measured waveforms. Although air- and water-filled voids did distort the reflected waveforms, a model was developed to predict the reflected waveforms from the simulated defects. Reinforcement was found to affect the reflected waveforms only when it was oriented in a direction perpendicular to the GPR antennas. A model was also developed to predict the GPR waveforms obtained from flexible pavements. This model could be used in a procedure to measure layer thicknesses more accurately by including losses that occur inside the pavement materials. Two different case studies, where a ground-coupled GPR system was used to locate moisture at different layers, have led to the conclusion that the ground-coupled GPR is a feasible tool to detect moisture inside pavements. / Ph. D.

The corrosion protection performance of epoxy-coated reinforcing steel (ECR) was evaluated in 18 concrete bridge decks in Virginia in 1997. The decks were 2 to 20 years old at the time of the investigation. The concrete bridge deck inspections included crack survey and cover depth determination in the right traffic lane. Maximum of 12 cores with the top reinforcement randomly located in the lowest 12th percentile cover depth and 3 cores with the truss bars were drilled from each bridge deck. The concrete core evaluation included visual examination and determination of carbonation depth, moisture content, absorption, percent saturation and chloride content at 13 mm depth. Rapid chloride permeability test was also performed for the surface and base concrete on samples obtained from cores containing truss bars. The ECR inspection consisted of visual examination and damage evaluation, coating thickness and adhesion determination. The condition of the steel underneath the epoxy coating was also evaluated. Adhesion loss of the epoxy coating to the steel surface was detected for 4 years old bridge decks. The epoxy coating had debonded from the reinforcing bar before the chloride arrival. Visible signs of a possibility of a corrosion process underneath the coating suggest that ECR will not provide any or little additional service life for concrete bridge decks in comparison to black steel. Other systems, which will provide longer protection with a higher degree of reliability against chloride induced corrosion of steel in concrete, should be considered. / Ph. D.

Two 7" deep FRP deck panels were manufactured and tested in a controlled service environment. The deck panels were 15' by 5' in plan, and were composed of ten 15' long, 6" by 6" by 3/8" standard pultruded FRP tubes. The tubes were sandwiched between two 3/8" thick standard pultruded FRP plates. The material constituents of the FRP were E-glass fibers in a polyester matrix. When subjected to two strength tests, the first deck panel exhibited a safety factor with respect to legal truck loads of greater than 10. The second deck was subjected to AASHTO design loads, and under a simulated HS-25 axle plus impact the deck exhibited a maximum deflection of L/470. Upon completion of the laboratory testing, the second deck was placed in the field for further study. The maximum strain recorded during field testing was approximately 600 microstrain, which is less than 15% of the ultimate tensile strain of the FRP in its weakest direction. After being subjected to approximately 4 million load cycles (assuming 100,000 5-axle truck crossings per month) over a period of 8 months, the deck exhibited no loss in stiffness. In two post-service strength tests, the second deck exhibited a safety factor with respect to legal truck loads of greater than 8 and greater than 13. / Master of Science

This thesis presents research completed on the experimental performance of two 6 3/4 in thick bridge deck panels fabricated by the Stongwell Corporation of Bristol, Virginia. The panels are made of off-the-shelf, pultruded glass fiber-reinforced polymer elements, bonded and mechanically fastened together. The testing involved laboratory stiffness tests performed on one deck panel which afterwards, was placed in a field test site at the I-81 Troutville Weigh Station facility. The daily truck traffic over the deck panel at this site is approximately 5400 vehicles. The second deck panel was constructed as a prototype to test benefits of steel thru-rod mechanical connectors. Further, a rubber tire loading patch was developed for the laboratory stiffness and strength tests performed on this second specimen to investigate modes of failure. Both decks made use of a hook bolt type connection to steel support beams in order to reduce damage seen in previous methods of connection. / Master of Science

A model to determine the time to first repair and subsequent rehabilitation of concrete bridge decks exposed to chloride deicer salts that recognizes and incorporates the statistical nature of factors affecting the corrosion process is developed. The model expands on an existing deterministic model using statistical computing techniques, including resampling techniques such as the parametric and simple bootstrap. Emphasis was placed on the diffusion portion of the diffusion-cracking model, but advances can be readily included for the time for corrosion deterioration after corrosion initiation. Data collected from ten bridge decks built in Virginia between 1981 and 1994 was used to model the surface chloride concentration, apparent diffusion coefficient, and clear cover depth. Several ranges of the chloride corrosion initiation concentration, as determined from the available literature, were investigated. The time to first repair and subsequent rehabilitation predicted by the stochastic model is shorter than the time to first repair and subsequent rehabilitation predicted by the deterministic model, but is believed to more accurately reflect the true nature of bridge deck deterioration. The model was validated using historical service life data for 129 bridge decks built in Virginia between 1968 and 1972. The time to rehabilitation predicted for the set of bridge decks built between 1981 and 1994 by the stochastic model was approximately 13 years longer than the normalized time to rehabilitation projected for the bridge decks built between 1968 and 1972 using historical data. The increase in time to rehabilitation for the newer set of bridge decks was attributed to a reduction in the specified maximum water/cement ratio and increase in clear cover depth. / Master of Science