The Cornwall Water Purification Plant collaborated with the University of Toronto to monitor UV-H2O2 treatment performance. This study includes a review of engineering and operational aspects of UV-H2O2 implementation. A number of operational challenges were experienced with retrofitting UV-H2O2 into the existing treatment plant, and an overview of the challenges and solutions faced at Cornwall is given. The project also includes a thorough water quality analysis. Taste and odour (T&O) events have been monitored for three years and the efficiency of UV-H2O2 on T&O removal is reported. Furthermore, little is known about any potential side effects of the treatment on downstream processes, especially secondary disinfection. The impact of UV-H2O2 on natural organic matter alterations, chlorine stability and disinfection by-product formation is reported using results from full-scale water quality monitoring campaigns at Cornwall, combined with laboratory experiments.

The design of buildings for extreme loads has traditionally been conducted on a life safety basis. As a result, buildings often need to be demolished after an extreme event since the cost of repairing the extensive damage is too great. For many buildings, especially critical infrastructure, continued operation after an explosive attack is essential. The use of energy-dissipating methods in a componentized system will enable the protection of a structure and occupants from a blast and permit the rapid repair and re-occupation of the building after an explosive attack. This study focuses on the characterization of a componentized system utilizing energy-dissipating component assemblies. From this characterization, a predictive theory, based on a single degree of freedom model, is developed and a general design method proposed. The predictive theory and design method are evaluated in field blast tests.

This research program is focused on the photocatalytic cement with emphasis on evaluating impacts on concrete’s physical, transport and durability properties. The scope of this project is to examine three key aspects of photocatalytic concrete including: a critical review of currently reported applications; an examination of air pollution concentrations in Ontario to assess the potential effectiveness of photocatalytic concrete, with respect to NOx; and an experimental study to characterize the material properties. Research findings revealed comparability between photocatalytic concrete and conventional concrete in mechanical and fluid transport properties. Although photocatalytic concrete resisted rapid freeze and thaw damage very well, in terms of de-icer salt scaling performance, only formed surface performed well and highly variable results for photocatalytic and GU concrete was observed for the finished surface.

Energy derived from biomass has been proposed as a means to attain various environmental, economic and social goals. However, bioenergy production and utilization may also result in undesirable environmental and social consequences. This thesis investigates, from a life cycle perspective, environmental and cost implications of near-term bioenergy applications in the transportation and electricity sectors. Key tradeoffs related to the attributes of the systems are elucidated. Three case studies are conducted to consider the site-specific nature of bioenergy systems. The first two studies analyze the environmental and cost implications of displacing coal with biomass for electricity generation in Ontario’s coal generating stations. The third study examines implications of replacing gasoline with ethanol for use in California’s light-duty vehicle fleet to meet the State’s Low Carbon Fuel Standard (LCFS). The Ontario studies show that, relative to coal-based electricity generation, electricity generated from co-firing 10% (energy input) biomass with coal reduces greenhouse gas (GHG) emissions by 8% at a cost of $22/tonne CO2 equivalent for agricultural residues ($50/dry tonne residues delivered), and by 9% at a cost of $70-$84/tonne CO2 equivalent for wood pellets ($160/tonne pellets delivered), on the basis of one kWh of electricity generated (all costs are in U.S. dollars). One hundred percent pellet firing reduces GHG emissions by 91% compared to the coal system; however, the cost of GHG reduction is $99-$106/tonne CO2 equivalent. Displacing a portion of gasoline with ethanol is a feasible option to meet California’s LCFS, which calls for a 10% carbon intensity reduction of the State’s transportation fuels by 2020. Assuming current production methods and an indirect land use change effect of 30 g CO2/MJ, average Midwest corn ethanol is ruled out as an option to meet the LCFS. Using lignocellulosic ethanol to meet the LCFS is more attractive than using Brazilian sugarcane ethanol due to lower direct agricultural land requirement, dependence on imported energy, projected ethanol cost, required refuelling infrastructure modifications, and penetration of flexible fuel E85 vehicles. The thesis demonstrates that a life cycle approach is useful for analyzing and comparing different bioenergy applications, and providing insights into tradeoffs necessary in decision making for the development of next generation energy systems.

The Cornwall Water Purification Plant collaborated with the University of Toronto to monitor UV-H2O2 treatment performance. This study includes a review of engineering and operational aspects of UV-H2O2 implementation. A number of operational challenges were experienced with retrofitting UV-H2O2 into the existing treatment plant, and an overview of the challenges and solutions faced at Cornwall is given. The project also includes a thorough water quality analysis. Taste and odour (T&O) events have been monitored for three years and the efficiency of UV-H2O2 on T&O removal is reported. Furthermore, little is known about any potential side effects of the treatment on downstream processes, especially secondary disinfection. The impact of UV-H2O2 on natural organic matter alterations, chlorine stability and disinfection by-product formation is reported using results from full-scale water quality monitoring campaigns at Cornwall, combined with laboratory experiments.

The design of buildings for extreme loads has traditionally been conducted on a life safety basis. As a result, buildings often need to be demolished after an extreme event since the cost of repairing the extensive damage is too great. For many buildings, especially critical infrastructure, continued operation after an explosive attack is essential. The use of energy-dissipating methods in a componentized system will enable the protection of a structure and occupants from a blast and permit the rapid repair and re-occupation of the building after an explosive attack. This study focuses on the characterization of a componentized system utilizing energy-dissipating component assemblies. From this characterization, a predictive theory, based on a single degree of freedom model, is developed and a general design method proposed. The predictive theory and design method are evaluated in field blast tests.

This research program is focused on the photocatalytic cement with emphasis on evaluating impacts on concrete’s physical, transport and durability properties. The scope of this project is to examine three key aspects of photocatalytic concrete including: a critical review of currently reported applications; an examination of air pollution concentrations in Ontario to assess the potential effectiveness of photocatalytic concrete, with respect to NOx; and an experimental study to characterize the material properties. Research findings revealed comparability between photocatalytic concrete and conventional concrete in mechanical and fluid transport properties. Although photocatalytic concrete resisted rapid freeze and thaw damage very well, in terms of de-icer salt scaling performance, only formed surface performed well and highly variable results for photocatalytic and GU concrete was observed for the finished surface.

Doctor of Philosophy / Civil Engineering / Mustaque A. Hossain / Geocellular confinement systems (geocells), three-dimensional honeycomb-like structures containing an infill of available materials such as sand or crushed limestone, vastly improve shear strength of infill materials. Geocells are potential solutions for challenges associated with low-volume paved road reconstruction. The objectives of this study were to test geocell designs with various infill materials and a thin hot-mix asphalt overlay under full-scale traffic load and to numerically model this problem. Therefore, eight pavement test sections were constructed at the Civil Infrastructure System Laboratory at Kansas State University, Manhattan, Kansas. Repeated loads (80-kN, single axle) were applied to the pavement sections using an accelerated pavement testing machine till failure. Pavement sections were modeled three-dimensionally using Abaqus, a commercially available finite element software package. Effects of geocell height and location were simulated in the geocell-reinforced bases, and pavement structures were modeled as three-layered systems. Results showed that proper geocell height, infill material and cover depth to protect the geocells during construction are necessary to ensure long-term performance of geocell-reinforced pavements. Such pavement structures with low- quality infill materials can perform as well as conventionally-constructed pavement structures.

Master of Science / Department of Civil Engineering / Stefan A. Romanoschi / The primary objective of this research project was to evaluate the shear behavior of three asphalt-to-asphalt mix interfaces. To accomplish this objective, a special attachment and loading mechanism was designed and built to facilitate the measurement of the dynamic shear reaction modulus and shear strength of the asphalt-to-asphalt interfaces when shear and normal forces are acting simultaneously and they are proportional. Two tests were conducted on 4-inch diameter cylindrical samples cored from an asphalt concrete pad where three types of asphalt-to- asphalt interfaces were built. For each interface, four tack-coat quantities were sprayed. On each sample, the Dynamic Shear Reaction Modulus test was conducted first. Then the Shear Strength test was conducted until the sample failed in shear at the interface. The experiments suggest that the shear strength of the interface is affected neither by the interface type nor by the tack-coat application rate. However, the dynamic shear reaction modulus was affected by both interface type and by the tack-coat application rate. The lowest moduli were recorded for the interface between two fine graded asphalt mixes. With very few exceptions, the highest moduli were obtained for the tack-coat application rate recommended by the construction specification.

Master of Science / Department of Civil Engineering / Mustaque A. Hossain / Due to budget constraints, many highway agencies are becoming interested in pavement preservation or rehabilitation rather than reconstruction to ensure pavement is in serviceable condition. Thin whitetopping (TWT) is the process of rehabilitation of distressed asphalt concrete (AC) pavements using a concrete overlay. This study was done to develop a design catalog for existing AC pavements to be overlaid with TWT. The finite element (FE) analysis was performed with SolidWorks, a 3-D FE software program to develop this design catalog. The design considered different TWT thicknesses, existing AC layer thicknesses and modulus, bonding conditions between TWT and existing AC layer, shoulder conditions and temperature differentials. Each model was built as a three-layer pavement system—concrete (TWT), asphalt layer, and subgrade soil. The traffic load was modeled as a constant pressure with a rectangular area applied at the surface and with intensity equal to the tire inflation pressure of 100 psi. The expected lives of TWT overlays were estimated using fatigue equations developed by the Portland Cement Association (PCA). Results obtained from this study show that interface bonding condition is the most important factor affecting the behavior of TWT. With the increase of TWT thickness or existing AC thickness or AC modulus, and addition of paved shoulder, concrete tensile stress decreases. Curling stress increases with the increase of TWT thickness and is not a function of AC properties. A design catalog was developed in terms of service life of the pavement. Unlike unbonded TWT with unpaved shoulder that results in catastrophic loss of rehabilitated pavement life, bonded TWT is expected to last 10 years, assumed in design. Thus, proper bonding must be ensured in order to have extended pavement life.