Iodine number, BET surface area, taste and odour compound isotherms, and trace capacity number tests were used to rank five different granular activated carbons according to thermodynamic adsorption performance. These tests were compared to expected activated carbon service life and loading results of rapid small-scale column tests (RSSCTs) run with water from two lake sources spiked with geosmin and 2-methylisoborneol (MIB). Trace capacity number, used to specifically identify high adsorption energy sites on activated carbon, was hypothesized to be correlated to geosmin/MIB breakthrough and loading performance of different activated carbons. This study found no such clear correlation. However, when only bituminous coal activated carbons were considered, correlations to MIB breakthrough were strengthened. Natural organic matter (NOM) adversely affected adsorption, resulting in decreased RSSCT throughput to breakthrough in surface water with higher total organic carbon (TOC). Methods for improving characterization tests and RSSCTs when NOM is present are discussed.

In 2011, Roger Xu (UToronto) carried out an experimental study to investigate shear reinforcement ratios required to cause crushing of diagonal struts in high-strength reinforced concrete I-beams. Xu’s experimental results were found to be inconclusive due to detailing issues resulting in flange splitting and web blow-out. This thesis outlines an experimental test programme completed in Spring 2012 to mitigate the issues encountered by Xu. Through experimental observation, data acquisition, and numerical analysis, the test program described in this thesis is shown to overcome the aforementioned issues. The study is expanded upon with an additional test series of rectangular beams aimed to examine the applicability of the maximum shear capacity provision of the Canadian Standards Association (CSA) A23.3-04 design standard. Test data suggests that the 0.25fc'bwdv upper limit for shear reinforcement used in CSA A23.3-04 cannot be reliably attained when using high strength concrete.

To investigate the benefit induced by adding a small amount of bonded reinforcing steel into a fully unbonded prestressed concrete beam, two well-founded and straightforward approaches for predicting tendon stress are proposed. The primary approach utilizes a flexural analysis to calculate member deformation. The supplementary approach employs a truss model to consider the additional member deformation due to shear force. Both approaches use a simplified iterative method. With these two approaches, a systematic parametric study is conducted to investigate the effects of various factors. The results indicate that adding little bonded reinforcement does significantly increase the stress increment in unbonded tendons at ultimate state for one-point loading as expected. Moreover, a lower span-to-depth ratio, the use of high-strength concrete, and a smaller mechanical reinforcement ratio also raise the stress increment.

The flatbed scanner method for air void analysis of concrete is investigated through a comparison study with the standard ASTM C457 manual and Rapid Air 457 test methods. Air void parameters including air content and spacing factor are determined by image analysis of a large population of scanned samples through contrast enhancement and threshold determination procedures. It is shown that flatbed scanner method is giving comparable results to manual and Rapid Air 457 methods. Furthermore, a comparison of the air void chord length distributions obtained from the two methods of flatbed scanner and Rapid Air 457 has been implemented in this research. The effect of having different settings in the scanning process of scanner method is also investigated. Moreover, a threshold study has been performed that showed the flatbed scanner method can be employed in combination with manual and Rapid Air 457 methods as a time and cost saving strategy.

Underground mining can be summarized as the removal of economically viable volumes of rock which creates underground voids. In order to optimize ore extraction, a material is used to backfill these openings prior to creating any adjacent openings. The use of cemented paste backfill (CPB), a mixture of mine tails, water, and cement binder, has gained prominence as it not only provides a material that has engineered strength and can be deployed rapidly, but also decreases the surface storage volume of the mine tails. There is limited knowledge about the behavior of the stresses within the CPB during the filling of an underground opening, particularly during the early curing ages of the hydrating CPB which is critical to the design of fill barricades. This thesis presents a design procedure which can be used to determine the in situ stresses within the CPB. Three methodologies were used in the development of this design procedure. The first was to develop a laboratory testing method that determined the time-dependent consolidation characteristics and strength parameters of the hydrating cemented paste material. The second was to collect several field-data sets. The third methodology was to numerically model the CPB using Itasca’s FLAC3D, which incorporated the underground void’s geometry, backfilling strategy, and time-dependent backfill parameters in order to determine the in situ stresses of the CBP. This simulation allowed for the prediction of both total and effective stress throughout the stope. The model and the laboratory results were used to model the stresses in several test stopes so that a comprehensive comparison could be made between the model and field instrumentation results. Four case studies were examined using a total of six different field instrumentation datasets. The results from these case studies showed that the modeling approach, given some model calibration, is capable of quantitatively representing the important geomechanical aspects of paste filling and curing.

Water supply and distribution infrastructures are vital for current life. They have a significant role in public health, providing safe water for drinking and human consumption as well as for essential non-potable uses such as fire fighting. These diverse objectives create challenges for everyone who must address in some way the actual performance of the system. This research critically evaluates all common objectives of conventional design approaches and evaluates the advantages and drawbacks of various performance measures. New ideas for a more realistic and comprehensive approach to the design, operation assessment of WDS are proposed. A new approach, called a Risk-based Performance Assessment, for hydraulic performance evaluation is tentatively proposed. It is based on integration of reliability, resiliency, and vulnerability as three basic operational indices in the operation of WDS. Furthermore, the Total Life-cycle Cost evaluation approach is tentatively proposed based on considering all major costs of a WDS.

The relationship between monthly transit pass ownership and home-work trip mode choice in the Greater Toronto Area was explored using a logit formulation. A Nested Logit model was specified with the primary mode (non-motorised, auto, transit, or auto access to transit) in the upper level and the pass ownership in the lower transit nests. Inclusive value parameters confirm the chosen structure, and a range of policy sensitive, statistically significant parameters having expected signs and magnitudes reveal differences between socio-economic characteristics of pass holders and non-pass holders. In particular, pass holders are less likely to possess a driver’s license or automobile than non-pass holders, implying that passes can be thought of as complementary mobility tools. Cost parameters, which include differentiated pricing for pass and non-pass holders, result in plausible in-vehicle values of time of approximately $31/hour, $33/hour and $8/hour for auto, auto access to transit, and transit all way, respectively.

The work presents a framework for analyzing complex decision making in policy from the perspective of planning power supply mix for Ontario. Concepts of sustainability are introduced and analyzed followed by an in-depth view of two case studies. The first analyzes the power supply mix for Ontario and the second analyzes policy impacts in Germany and Denmark. A linear programming model, including energy storage is then developed that would yield an optimized sustainability based development policy for electricity production in Ontario. Future work is recommended to calibrate and run the model. The analysis discusses the new model in relation to the first case study and provides a mechanism to evaluate tradeoffs traditionally unquantifiable, to yield a strategic plan for electricity development in Ontario.

Measurement of the strength development of Cemented Paste Backfill in laboratory cast cylinders does not replicate the in situ strengths of CPB in mine stopes. The mass of CPB in a filled stope is large and temperature rises due to the heat of hydration of the cementing materials, thus accelerating the gain in strength, relative to laboratory specimens stored at ambient temperature. The purpose of this study was to determine the impact on strength development when CPB test cylinders were subjected to a temperature profile mimicking that in a large mass, such as a mine stope. Also, maturity (the integral of time and temperature during hydration of the CPB) was compared to actual strengths, and the maturity – strength concept used in concrete technology was applied. It was found that the strength- maturity relationship was applicable to CPB once the base line or datum temperature was adjusted.

Iodine number, BET surface area, taste and odour compound isotherms, and trace capacity number tests were used to rank five different granular activated carbons according to thermodynamic adsorption performance. These tests were compared to expected activated carbon service life and loading results of rapid small-scale column tests (RSSCTs) run with water from two lake sources spiked with geosmin and 2-methylisoborneol (MIB). Trace capacity number, used to specifically identify high adsorption energy sites on activated carbon, was hypothesized to be correlated to geosmin/MIB breakthrough and loading performance of different activated carbons. This study found no such clear correlation. However, when only bituminous coal activated carbons were considered, correlations to MIB breakthrough were strengthened. Natural organic matter (NOM) adversely affected adsorption, resulting in decreased RSSCT throughput to breakthrough in surface water with higher total organic carbon (TOC). Methods for improving characterization tests and RSSCTs when NOM is present are discussed.