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The City of Saskatoon (COS) manages diverse road infrastructure assets. Given the present day challenges of structurally upgrading in-service road infrastructure assets in diverse field state conditions, there is a need to incorporate new innovative materials, changing field state conditions, and mechanistic design methods in sustainable road rehabilitation decision making. The COS is faced with challenges including rising material and labour costs, budget shortfalls, depleting virgin aggregate sources in close proximity to the COS, and an increase in stockpiled asphalt and concrete rubble materials due to transportation infrastructure renewal. As a result of the COS impact crushing program, a need to determine the design and performance properties of using recycled reclaimed asphalt concrete (RAP) rubble materials in urban pavement structures was established. RAP materials had never been used as a structural base layer in COS pavement structures because no material characterization had been conducted and there was no performance information with regards to their structural behaviour and field performance available. Other jurisdictions documented benefits of using recycled RAP in road structure include: reduced demand on depleting aggregate sources; reduced energy consumption; diversion of stockpiled RAP materials from landfills; and reduced overall handling and disposal costs. Given the amount of crushed RAP material available to the COS, it was determined there are potential benefits to implementing the use of recycled crushed RAP rubble in pavement structures, leading to the implementation of the “Green Street” Infrastructure Program. The findings of this research indicate that RAP materials have improved mechanistic properties compared to conventional granular materials; therefore, RAP materials can be used as a base layer in a road structure. This research indicates that cement stabilization and cement with a slow setting (SS-1) emulsion stabilization improved the moisture susceptibility of well graded (GW) and open graded base course (OGBC) RAP materials. These findings demonstrated that RAP materials stabilized with cement and/or SS-1 emulsion can be used as a base layer in a pavement structure. This research also found that the standard Proctor compaction method is not applicable for RAP materials to quantify moisture-density behaviour under compaction, due to the bound-nature of RAP aggregates, which are composed of asphalt and aggregate. California bearing ratio (CBR) values of Proctor-compacted RAP specimens did not accurately reflect field performance observations. As part of the COS “Green Street” Infrastructure Program, two test sections using crushed GW RAP rubble materials as a base layer were constructed as part of this research and include Marquis Drive (eastbound lanes from Thatcher Avenue to Idylwyld Drive) and 8th Street East (westbound lanes from Boychuk Drive west 0.540 kilometers). Test sections were constructed by the City of Saskatoon with conventional construction equipment and showed structural improvement in structural performance and visual distresses. Using RAP materials as a base layer was economically feasible because the RAP material cost less than conventional virgin aggregate base materials. This research demonstrates that processed and crushed RAP rubble materials are technically feasible to be used as a structural base layer in a recycled pavement structural system for urban road rehabilitation systems, and provide economic benefits over conventional granular base materials.

7 pp. / Agriculture is by far the largest water-demanding sector in Arizona, accounting for 70% of water demand (ADWR, 2009). Arizona’s agriculture industry is extremely diversified, producing many crops that can legally be irrigated with recycled water, including cotton, alfalfa, wheat, citrus, and vegetables. Throughout the State, farming communities are taking advantage of increasing supplies of recycled water.

The amount of waste tyres being dumped is fast becoming a problem. These stockpiles take up valuable land and are an environmental and health problem. While incineration is the simplest way to recycle the used tyres it isn’t an efficient way to dispose of tyres. This research looks at developing a method for characterizing the New Reclamation Group (NRG) reclaim with the main focus on Hi-Res™ thermogravimetric analysis. Good quantification was possible using this technique. A trade off was established between resolution, sensitivity and time. While increasing the resolution allowed greater separation to be achieved the time for each experiment increased rapidly. Although kinetic models do exist for quantifying rubber components in vulcanized sample, they were not suitable for this study. When devulcanization causes significant molecular changes, such as with NRG reclaim, the decomposition profiles no longer match those of virgin materials. Formulations developed focused on mixing, rheometry, crosslink density and tensile properties. The NRG reclaim acted as a processing aid which lowered the maximum torque. This provides mixing safety as the temperature is decreased as a result of the lower torque. This effect was not seen with conventional reclaim. Rheometry tests indicated that the addition of the devulcanizates decreased the extent of cure. It was demonstrated that this could be linked to crosslink density. Testing of the 100%, 200%, 300% moduli correlated the crosslink density to the maximum torque. Although the addition of NRG reclaim reduced the tensile strength of the formulation, a link between crosslink density and ultimate tensile strength (UTS) couldn’t be made. The decrease in the UTS and increase in extension at break is possibly caused by an increase in low molecular weight material present in the formulations and decrease in crosslink density. This could possibly increase the mobility of polymer chains which could increases flexibility.

This thesis investigates the effects of using various percentages of RAP and asphalt binder contents on the dynamic modulus and fatigue resistance of asphalt concrete. Two RAP percentages (20% and 40%) and three binder percentages (plant-mixed, plant-mixed + 0.5%, and plant-mixed + 1.0%) were evaluated. A Superpave gyratory compactor and an asphalt vibratory compactor were used to prepare dynamic modulus samples and fatigue beam samples at 7% air voids. Three replicate samples for each percentage of RAP and asphalt binder content were prepared for testing purposes. An Interlaken Technology Corporation servohydraulic testing machine and a Material Testing System servohydraulic machine were used to determine the dynamic modulus and fatigue resistance of the asphalt samples. Analysis of variance (ANOVA) was used to determine if any of the factors (air voids, percent RAP, and percent asphalt binder) affected the performance criteria (dynamic modulus and fatigue life cycles). Results suggest that as the amount of RAP increases in asphalt concrete, both the dynamic modulus and fatigue life will increase. As per the literature, these results were expected for the dynamic modulus, but not for the fatigue life. It is suspected that the increase in fatigue life for the 40% RAP mixes may be due to the use of a softer binder (PG 64-22 instead of PG 70-22).  It was also found that by increasing the amount of binder in the mixture, the stiffness of asphalt concrete will decrease, but the fatigue life will improve. The fatigue life results showed a strong trend of this improvement for the 20% RAP samples, however, the results for the 40% RAP samples were inconclusive. For dynamic modulus, it was found that the percent RAP, additional binder, frequency, and temperature were all statistically significant with 95% confidence. For the fatigue life, ANOVA showed that the percent RAP and additional binder were statistically significant with 95% confidence. These results suggest that by utilizing a higher percentage of RAP and asphalt binder, it is possible to meet or improve upon the dynamic modulus and fatigue life of the lower percentage of RAP samples. / Master of Science

Water reuse is increasingly pursued to alleviate global water scarcity. However, wastewater treatment process does not achieve full removal of biological contaminants from wastewater, and hence some microorganisms and their genetic elements can be disseminated into the reclaimed water distribution systems (RWDS). A systematic identification and characterization of these biological contaminants is required. However, a broad characterization for large-scale data are limited. In this study, reclaimed water samples are investigated through metagenomic analyses to assess their bacterial and functional (metal resistance genes (MRGs); virulence factors (VFs)) communities at the entry and exit points of the RWDS. Furthermore, water quality data are investigated to evaluate the potential relationship with these metagenomic annotations. This study found that the organic carbon content was likely relevant to the increase of bacteria and functional genes in RWDS. It was also found that the variation of functional genes was not associated with their host, inferring the role of horizontal gene transfers or promiscuity of hosts for various functional genes. Furthermore, Pseudomonas was identified in one RWDS with significant increase at both bacterial and functional levels.

Foamed asphalt stabilized material as a high quality granular base incorporating high percentages of fine fractionated reclaimed asphalt material is investigated. A foamed asphalt mix is designed using a fabricated asphalt foaming device. The final specimens are tested for indirect tensile strength, indirect tensile resilient modulus, triaxial resilient modulus, triaxial repeated load permanent deformation, and unconfined compression. Results are compared to those with the same aggregate blends without stabilization for triaxial resilient modulus and repeated load permanent deformation. Stabilized materials are tested in soaked and unsoaked states to establish moisture susceptibility. Foam stabilization is found to significantly improve triaxial resilient modulus in all materials as well as permanent deformation resistance in materials with high RAP content. Soaking only marginally reduces triaxial resilient modulus and the effects are lesser in materials incorporating high RAP content. / Thesis / Master of Applied Science (MASc)

The goal of this study was to assess the effect of residence time on the chemical and microbial quality of reclaimed water in two distribution systems located in southern Arizona. Utility A produced Class A water and utilized chlorine as a means of disinfection whereas Utility B produced Class A+ water and utilized UV radiation as a means of disinfection. Water-based pathogens were consistently detected in both distribution systems beyond the point of compliance, while microbial indicators like Escherichia coli was only detected in Utility B suggesting that treatment eliminated waterborne pathogens. Heterotrophic plate concentrations in samples from both utilities initially increased rapidly with increased distance from the point-of-compliance and were as high as 10⁹ CFU/100ml. Regardless of the initial level of treatment, the microbial quality deteriorated with increased residence time in the distribution systems. The second study was designed to evaluate the effect of reclaimed water storage on microbial and chemical quality of two classes of reclaimed water (Class A and Class A+). In Class A water, nitrification was observed during both field scale trials resulting in concentrations greater than 10mg/L while nitrification was not observed in Class A+. Chlorine residuals rapidly decreased within 48hours of storage. HPC concentration were as high as 10⁷ - 10⁸ /100ml. In both field scale trials, there was no observed growth of HPC during storage and waterborne indicator bacteria were rarely detected, and if detected, only at low concentrations. Based on this data, deterioration of microbial water quality during storage is minimal.

With the ever increasing demand for potable water due to the continued increase in population coupled with the threat of California’s current drought, water will remain a limited resource that must be managed responsibly. In order to strategically plan and manage water use in the most beneficial manner, water providers must take into account all sources of water, including recycled water and their applications. Recycled water as a source for supplementing high quality potable water is a sustainable strategy that will prove to be an essential tactic in any water management plan. The purpose of this project is to emphasize the importance of supplementing potable water in the City of Banning by discussing the characteristics of California’s current water drought; evaluating the City of Banning’s available water supplies and current water demand; discussing the Soil Aquifer Treatment process; summarizing California’s regulations related to recycled water; and discussing the quality of recycled water available at NP-1, an unequipped City owned water well, by examining water quality testing on water samples taken from NP-1. Analysis of water available at NP-1 showed that with additional disinfection, the water pumped from NP-1 could meet the recycled water requirements in order to be used on a local golf course. The local golf course is currently being irrigated with potable water, which would be supplemented with the recycled water from NP-1.

The golden-winged warbler (Vermivora chrysoptera) inhabits lower elevations on reclaimed surface mines in Kentucky, an indication of recent range expansion in this imperiled species. In 2004 and 2005, I compared breeding habitat between the golden-winged warbler and blue-winged warbler (V. pinus) in eastern Kentucky at landscape, territory, and nest site scales. Distance to forest edge averaged 38 m for the golden-winged warbler and 33 m for the blue-winged warbler. Maximum territory size averaged 1.5 ha for the golden-winged warbler and 2.1 ha for the blue-winged warbler. The golden-winged warbler occurred at higher elevations (up to 912 m) than the blue-winged warbler (up to 693 m). Golden-winged warblers occurred on flatter slopes when coexisting with bluewinged warblers. A higher percentage of grass cover occurred in golden-winged warbler territories where blue-winged warblers were absent compared to territories of either species where the two coexisted. Golden-winged warblers coexisting with blue-winged warblers were more often found in shrub cover than when they established territories in absence of blue-winged warblers. Management for the golden-winged warbler should focus on enhancement of transition zones between forest edges and open grasslands, especially at higher elevations.