The use of fibre reinforced polymer (FRP) composites for strengthening reinforced concrete structures has become increasingly popular in recent years. However, before FRPs can be implemented in interior building applications their performance during fire must be assessed and understood. There currently remains a paucity of information in this area for most currently available FRP strengthening systems. This thesis presents a study of the mechanical and bond properties of selected currently available FRP strengthening systems for concrete structures at elevated temperatures such as might be experienced during a fire. Testing has been performed and is reported to study the continuous unidirectional coupon tensile strength, lap-splice FRP-to- FRP shear bond strength and tensile elastic modulus at elevated temperatures. Results of thermal characterization tests are also completed in an attempt to relate properties of the polymer matrix, such as the glass transition temperature, and thermal decomposition temperature to the losses of strength and stiffness observed for FRP coupons during steady-state and transient exposure to elevated temperatures up to 200oC. A simple analytical model is presented, for which the input parameters can be determined using dynamic mechanical thermal analysis and thermogravimetric analysis, to describe the reduction in mechanical and bond properties of the FRP systems at elevated temperatures. Based on this testing and subsequent analysis it is recommended that a conservative limit on the allowable temperature exposure for FRP systems during fire be set as the glass transition temperature measured using dynamic mechanical thermal analysis. Furthermore it is suggested that differential scanning calorimetry may not be an appropriate method of determining the glass transition temperature for available FRP systems used in concrete strengthening applications. / Thesis (Master, Civil Engineering) -- Queen's University, 2013-04-30 19:06:24.31

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"Alternate models for extended ceiling convection heat transfer and ceiling vent mass flow for use in the Harvard Computer fire Code are developed. These models differ from current subroutines in that they explicitly consider the ceiling jet resulting from the fire plume of a burning object. The Harvard Computer fire Code (CFC) was used to compare the alternate models against the models currently used in CFC at Worcester Polytechnic Institute and with other available data. The results indicate that convection heat transfer to the ceiling of the enclosure containing the fire may have been previously underestimated at times early in the fire. Also, the results of the ceiling vent model provide new insight into ceiling vent phenomena and how ceiling vents can be modeled given sufficient experimental data. this effort serves as a qualitative verification of the models as implemented; complete quantitative verification requires further experimentation. Recommendations are also included so that these alternate models may be enhanced further. "

Lightweight wood construction is one of the most common forms of residential construction in the United States. Unprotected lightweight wood structural members are extremely sensitive to elevated temperatures often experienced in fire conditions. Residential fires are a commonly occurring incident across the globe and consequently make up a large percentage of residential property loss and damage. In the United States, building code provisions limit lightweight construction to particular building types. These building codes prescribe protected lightweight wood assemblies in building types for which they are allowed. Although many components of lightweight wood buildings are required to be protected in some form, there are still many parts of the building that are not necessarily required to be protected, especially in private residential structures. A fire may start in an area of a building that is protected, but may propagate into areas that are not. This leaves portions of the unprotected structure vulnerable to rapid fire damage. Lightweight wood members can quickly lose load resistance due to a loss of cross-section as a result of charring. Analytical models currently exist and are generally accepted for heavy timber elements, but the applications of these models do not extend to lightweight wood members. As a result, this thesis investigated the application of an analytical model to lightweight wood elements. In developing this model, the finite element method and finite difference models were used to investigate the phenomenon of wood char in fire conditions. Finite difference models were explored as an alternative to finite element models because finite difference formulations did not require specialty programs. Following the development of analytical char models, mechanics-based analyses were conducted to evaluate the performance of lightweight beams and columns exposed to fire conditions.

Fluorinated fire fighting foams provide superior performance for extinguishing Class B flammable liquid fires when compared to other types of fire fighting foams. Perfluorocarboxylates and perfluorosulfonates have historically been surfactants used in these foams with a recent shift to fluorotelomer-based foams due to environmental and health concerns surrounding perfluorinated compounds such as PFOA and PFOS. Releases of aqueous film forming foams from training, accidental spills, or fire events where wastewater is not captured have, among other sources, led to detectable concentrations of fluorinated compounds in groundwater, surface water, and drinking water supplies globally. Persistence, toxicity, and bioaccumulation potential of these substances are areas of ongoing research. Biodegradability data for these AFFFs in published studies and manufacturers’ material safety data sheets may be based on a comparison of BOD and COD measures. The present study concludes that COD is an inappropriate measure of organic content for fluorinated compounds due to the carbon-fluorine bond strength, and thus published biodegradability data must be critically evaluated for validity. TOC measured an average of 91% of carbon content for four fluorinated test substances, recommending it for use as an analytical parameter in biodegradability tests when specific compounds’ identities are not required, e.g. in the absence of an LC/MS. Biodegradability of three fluorinated foams (AFFF, AR-AFFF, and FP) purchased from a major U.S. manufacturer measured in the range of 77-96% based on DOC die-away during a 28-day test using activated sludge inoculum. This meets OECD criteria for “ready biodegradability� and NFPA biodegradability recommendations in Standards 18, 18A, and 1150. Defluorination of two foams was measured using ion chromatography and, based on an estimate for total fluorine content developed in part from manufacturer MSDSs, was found to liberate a detectable level of fluorine that was 1 to 2 orders of magnitude less than the estimated value. In this 28-day test, foams underwent significant biodegradation but fluorinated compounds’ biodegradation was likely incomplete.

This thesis demonstrates how the response of fire detection and automatic sprinkler systems can be designed or analyzed. The intended audience is engineers involved in the design and analysis of fire detection and suppression systems. The material presented may also be of interest to engineers and researchers involved in related fields. National Bureau of Standards furniture calorimeter test data is compared to heat release rates predicted by a power-law fire growth model. A model for calculating fire gas temperatures and velocities along a ceiling, resulting from power-law fires is reviewed. Numerical and analytical solutions to the model are outlined and discussed. Computer programs are included to design and analyze the response of detectors and sprinklers. A program is also included to generate tables which can be used for design and analysis, in lieu of a computer. Examples show how fire protection engineers can use the techniques presented. The examples show how systems can be designed to meet specific goals. They also show how to analyze a system to determine if its response meets established goals. The examples demonstrate how detector response is sensitive to the detector's environment and physical characteristics.

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The author of this thesis uses her own personal experience of the Old Fire that took place in the fall of 2003 in San Bernardino County to teach children ecological concepts, especially fire ecology using an art oriented methodology. Thus, heArts for the Forest was born incorporating ash from the burned forest into pottery and other art pieces to sell and raise money for reforestation efforts in the San Bernardino mountains.

Hydrophobic soils developing as a consequence of wildfires have a large impact on the environment. A greater understanding of when ideal hydrophobic development conditions occur is needed. This thesis aims to identify the impact of varying both soil moisture and soil particle size on the locations for ideal hydrophobic soil development under different intensities of burns. It builds on experiments completed previously to further the understanding of the effect of particle size on heat flow. All experiments done in the previous study used only dry sediment. This study focused on the role of moisture in hydrophobic soil development. A secondary goal of this thesis is to provide an opportunity to further explore convection as a mechanism of soil heating. An indoor wildfire simulator was employed, consisting of an array of propane burners, to determine the impact of varying factors under controlled conditions. The temperature levels and durations selected were based on data obtained from measurements taken during full-scale field based burns. Thermocouples were used to measure temperatures of the flames and temperatures at different depths within the sediment. Determining the impact of soil texture was done by running burns with sand, clay-loam, silt, and clay. The impact of soil moisture was determined by testing each of the sediment types with different levels of moisture. In total, twenty-four burns were completed with peak temperatures of 600 degrees C, 900 degrees C, and 1200 degrees C in order to simulate typical chaparral fires.

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