Given the current global crisis of deteriorating infrastructure, structural rehabilitation has been the focus of much recent research in the field of civil engineering. Consequently, Fibre Reinforced Polymers (FRP’s) are becoming an increasingly common method for retrofitting deficient structures. However, skepticism regarding the structural performance of FRP’s during fire is preventing their widespread implementation in building applications. Because of the degradation of FRP material properties during heating, most current design codes completely neglect their structural contributions in fire design. The intention of this research thesis is to investigate the thermal and mechanical behaviour of insulated FRP retrofitted reinforced concrete structures at elevated temperatures. Two intermediate-scale reinforced concrete slabs were first strengthened with FRP and protected with spray-on insulation. Thermal results from fire testing of the slabs provided a basis on which to develop insulation schemes for larger specimens. These larger specimens consisted of two full-scale T-Beams and two full-scale columns, which were also strengthened with FRP and insulated. All of these specimens succeeded in obtaining four hour fire ratings upon fire testing. Though the FRP strengthening systems were compromised quickly during heating, the insulation provided sufficient protection to the T-beams and columns for them to resist the applied service loads throughout the duration of fire exposure. Detailed calculations were also conducted using thermal data from the full-scale specimen fire tests in order to predict the change in capacity of these structures with time. This thesis shows that, with careful considerations towards insulation and anchorage design, FRP-strengthened reinforced concrete structures are able to obtain fire ratings in excess of four hours. / Thesis (Master, Civil Engineering) -- Queen's University, 2012-05-29 15:46:00.801

The Sprague’s pipit is a small, threatened grassland songbird endemic to the Canadian prairies and to the northern Great Plains of the United States. Between 1968 and 2006, the population of Sprague’s pipit in Canada experienced a significant annual decline of 4.5%. The prairie provinces also experienced declines within this reporting period. Pipits are more abundant in native prairie grasslands, however much of their preferred habitat has been lost due to the influence of human activities. Furthermore, management of remaining grasslands has impacted the quality of habitat through suppression of natural disturbances such as fire. Few studies have addressed how fire affects the occurrence and abundance of Sprague’s pipit, thus pipit response to fire is poorly understood. This study investigated the effect of fire on the density and distribution of Sprague’s pipit in south-western Manitoba by examining the associations between pipit density, invertebrate food resources and vegetation structure with fire history. Surveys to determine pipit abundance, invertebrate resources and vegetation structure were conducted in 2007; in 2008 only pipit abundance and vegetation surveys were conducted. Although there was no significant effect of invertebrate resource abundance on Sprague’s pipit density, the abundance of grasshoppers and ground beetles declined with increasing time since last burn, which suggests that longer fire-return intervals may reduce the availability of these prey species for pipits. Fire did not significantly influence the distribution and density of Sprague’s pipit in this region. However the response of the vegetation to fire may indicate that the existing fire-return interval is not contributing to the population decline of Sprague’s pipit, but that in the absence of fire, the habitat could regress to a state that does not meet the critical habitat needs of this species.

This study considered the long term effects and interaction between burning and grazing in the northern mixed-grass prairies on the grassland songbird community. Point counts were conducted to assess songbird species abundances in burned-grazed, burned-ungrazed, unburned-grazed, and unburned-ungrazed pastures along with habitat structure (litter depth, vegetation height and density) over a five year period; from the first year post burn in 2007 until the fifth year post burn in 2011. Generalized linear mixed models were used to analyse the interaction between year, burning, and grazing for songbird abundances and habitat structure. As time since burned increased, species abundances in burned-grazed pastures have become more similar with those in unburned-grazed while abundances in burned-ungrazed are becoming increasingly similar to those in unburned-ungrazed pastures. The effects of burning are different than those of grazing and both disturbances should be utilised in grassland management when possible.

No description available.

The use of lightweight building systems is very controversial as existing knowledge about their performance is limited. Not enough research has been conducted to determine the suitability of these modern construction technologies and there is an ongoing controversy as to whether they are an appropriate replacement to traditional construction techniques. The prime objective of this study is to present a number of methodologies to assess lightweight external walling systems focusing on thermal efficiency, structure and fire performance, which are currently the main driving forces for this industry. Traditionally, these areas have been studied separately but there is a need to integrate them in order to get comprehensive solutions to the way these systems are designed. The drive to achieve improvements in one of these specific areas could potentially result in reduced effectiveness in the others. That is the reason why an integrative approach is recommended. These techniques are meant to be applied in the design phase of building projects so as to provide early quantitative information about the systems analyzed. The methodologies described herein are then applied to real life light steel building solutions. Within this context, two different wall constructions are examined and conclusions made on their relative performance. The study highlights the importance of having analytical and experimental solutions as a framework for further development. Two different approaches have been considered to assess thermal efficiency, structure and fire performance. On the one hand, a prescriptive approach has been employed to establish regulation compliance. On the other hand, a performance based approach is taken to actually understand and explain how these systems work in real life conditions. The outcome is a comprehensive set of tools to assure both industry and other stake holders.

A fire in road tunnel can be dangerous and lead to serious consequences if not addressed appropriately. In a tunnel fire incident, creating a smoke free path for motorist evacuation and facilitating fire fighters to access the fire is critical for fire and rescue operations. A means of achieving this is to use ventilation fans to blow sufficient air down the tunnel ensuring no back-layering of smoke occurs upstream of the fire. The airflow necessary for such operation is known as the critical velocity which is a function of a number of factors includes; heat release rate, tunnel geometry, tunnel gradient etc. Among these parameters, the heat release rate is the most difficult to identify as this value is dependent on the types of vehicles, number of vehicles involved, the type of cargo and the quantity of cargo carried by these vehicles. There are also other factors such as the influence of ventilation condition, tunnel geometry and the use of legislation (to restrict hazardous vehicles entering in tunnel) that could affect the heat release rate in a tunnel fire. The number of possible fire scenarios is numerous. Based on current practise, fire size selection for most tunnel ventilation design often references various guidelines such as NFPA 502, BD78/99 or the PIARC technical committee report. The heat release rate, particularly for goods vehicle recommended by the guidelines varies from 20 to 30 MW. However, recent fire tests conducted in the Runehamar tunnel experiments indicate a higher heat release rate. These experiments suggest that heat release rate guidelines for goods vehicles might be underestimated. An ideal means to estimate the heat release rate in the tunnel is to use the oxygen consumption calorimetry technique. However, this approach is generally expensive, logistically complicated to perform and it is often not feasible to conduct such tests for a tunnel project at the initial design stage simply because the structure and systems are not ready for such activities. This research thesis presents an approach to establish a design fire in a road tunnel particularly the peak heat release rate for emergency tunnel ventilation system design. The analysis consists of two stages; stage one involves the use of a probabilistic approach (risk analysis) to identify the potential cause and type of vehicle which could result in a tunnel fire. Findings from the risk analysis are used in stage two in which Computational Fluid II Dynamics (CDF) modelling is used to establish the heat release rate in the tunnel considering factors such as fuel load, ventilation condition, tunnel geometry and ignition location. The Fire Dynamics Simulator (FDS 4.0.7), a CFD model of fire-driven fluid flow is used for the analysis and an urban road tunnel project in Singapore is used to illustrate this methodology. Other topic related to this research work includes the reconstruction for the Runehamar tunnel fire test using numerical approach to calibrate the FDS simulation model. The used of Probabilistic Bayesian approach and CFD approach using FDS to estimate the heat release rate in the tunnel is also investigated in this thesis. The effect of vehicle fire spread in road tunnel and numerical simulation of road tunnel fires using parallel processing is presented. Preliminary work in using FDS5 for tunnel simulation work is discussed as part of the research work in this project.

No description available.

No description available.

The Sprague’s pipit is a small, threatened grassland songbird endemic to the Canadian prairies and to the northern Great Plains of the United States. Between 1968 and 2006, the population of Sprague’s pipit in Canada experienced a significant annual decline of 4.5%. The prairie provinces also experienced declines within this reporting period. Pipits are more abundant in native prairie grasslands, however much of their preferred habitat has been lost due to the influence of human activities. Furthermore, management of remaining grasslands has impacted the quality of habitat through suppression of natural disturbances such as fire. Few studies have addressed how fire affects the occurrence and abundance of Sprague’s pipit, thus pipit response to fire is poorly understood. This study investigated the effect of fire on the density and distribution of Sprague’s pipit in south-western Manitoba by examining the associations between pipit density, invertebrate food resources and vegetation structure with fire history. Surveys to determine pipit abundance, invertebrate resources and vegetation structure were conducted in 2007; in 2008 only pipit abundance and vegetation surveys were conducted. Although there was no significant effect of invertebrate resource abundance on Sprague’s pipit density, the abundance of grasshoppers and ground beetles declined with increasing time since last burn, which suggests that longer fire-return intervals may reduce the availability of these prey species for pipits. Fire did not significantly influence the distribution and density of Sprague’s pipit in this region. However the response of the vegetation to fire may indicate that the existing fire-return interval is not contributing to the population decline of Sprague’s pipit, but that in the absence of fire, the habitat could regress to a state that does not meet the critical habitat needs of this species.

This study considered the long term effects and interaction between burning and grazing in the northern mixed-grass prairies on the grassland songbird community. Point counts were conducted to assess songbird species abundances in burned-grazed, burned-ungrazed, unburned-grazed, and unburned-ungrazed pastures along with habitat structure (litter depth, vegetation height and density) over a five year period; from the first year post burn in 2007 until the fifth year post burn in 2011. Generalized linear mixed models were used to analyse the interaction between year, burning, and grazing for songbird abundances and habitat structure. As time since burned increased, species abundances in burned-grazed pastures have become more similar with those in unburned-grazed while abundances in burned-ungrazed are becoming increasingly similar to those in unburned-ungrazed pastures. The effects of burning are different than those of grazing and both disturbances should be utilised in grassland management when possible.