Ehab Zalok

Development of Design Fires for Performance-Based Fire Safety Designs

This paper discusses a procedure for the development of design fires for buildings and presents a study undertaken to quantify design fires for commercial buildings. This procedure includes building surveys, full-scale experiments and computer modelling. In this study, a survey of commercial premises was conducted to determine fire loads and types of combustibles present in these buildings. Based on the results of the survey a number of fuel packages were designed that represent fire loads and combustible materials in commercial buildings. The fuel packages were used to perform full-scale, post-flashover fire tests to collect data on heat release rates, compartment temperatures and production and concentration of toxic gases. Results from these experiments are presented and discussed. The paper also discusses a computer modelling study in which a computational fluid dynamics model was used to simulate the tests and to model a fire in a real-scale commercial store.

Design Fire Experiments for Commercial Premises

Two series of experiments were conducted to determine the burning characteristics of different fuel packages, in both pre- and post-flashover fires, to develop data to characterize design fires for commercial premises. These fuel packages represented fuel loads determined from the survey of commercial buildings. Results suggest substantial differences in the burning characteristics of different stores. In this article, the description of the recommended design fires includes: (1) types of combustibles, (2) fire load density (MJ/m 2), (3) fire growth rate, and (4) yields of CO and CO2.

Preliminary Characterization of Physical Properties of Cross-Laminated-Timber (CLT) Panels for Hygrothermal Modelling

Cross-laminated-timber (CLT) panels are a type of relatively new wood-based structural panel, typically manufactured by laminating three or more layers of lumber together, with each layer rotated 90° relative to the neighbouring layers. This study explored preliminary assessment of the physical properties of a range of specimens for the purpose of initiating generating material property data for hygrothermal simulation of CLT building enclosure assemblies. Three types of five-layer CLT panels (nominally 130 mm thick) were made with Canadian softwood species, including spruce-pine-fir (SPF) from Eastern Canada and British Columbia, and hem fir from British Columbia, all glued with emulsion polymer isocyanate (EPI) as the adhesive applied between neighbouring layers. One type of three-layer CLT (nominally 90 mm thick) commercially manufactured in Europe using European spruce, with polyurethane adhesive, was also tested. Physical properties including density, thermal conductivity, liquid-water absorption, water-vapor permeability, sorption (moisture storage function), and air permeability were measured, mostly based on established international standards. To assess the impact of the adhesive on the hygrothermal properties of CLTs, test specimens used for most tests included at least one layer of adhesive, except those used for sorption tests, which used very small specimens. The properties were expected to mostly reflect the properties of the lumber used for CLT manufacturing. Variations in properties were found among these different CLT specimens; however, it was generally concluded that the differences caused by wood species and manufacturing methods would not be large enough to cause considerable differences in the hygrothermal properties or significantly impact the outcomes of hygrothermal simulation. With small-scale testing and very limited replication this study showed that the water-vapor permeability of CLT generally increased with an increase in relative humidity (RH), and the air permeance of the CLT specimens without visible gaps and checks was negligible.

Experimental Examination of the Structural Performance of Restrained HSS Steel Beams and their End Connections in Fire

This paper describes a series of full-scale tests performed in the fire research facilities of Carleton University, Ottawa, Canada. These tests are part of an experimental programme, whose objective is to investigate the structural performance of axially restrained tubular steel beams at elevated temperatures. The primary focus is to determine the effect of the beam end connections on the structural performance of the steel-frame assembly. Four unprotected steel-frame test assemblies, each composed of a hollow structural section (HSS) steel beam restrained between two HSS columns, were subjected to a standard fire while constantly loaded. The main parameters investigated were the end plate thickness and the degree of beam axial restraint. Two different end plate thicknesses were tested, 12.7 mm and 19.0 mm. The experimental results showed a considerable effect of the end plate thickness on the structural behaviour of the connection and the connected beam. Moreover, the fire tests have revealed different c...

MOISTURE MANAGEMENT PERFORMANCE OF WOOD-FRAME IN-FILL WALL IN SHANGHAI, CHINA

This paper discusses the results of a research project which aimed at determining the hygrothermal (i.e. thermal and moisture) performance of the Canadian wood-frame building envelope construction in the city of Shanghai in China. The performance assessments of the wood-frame walls were conducted using the two-dimensional hygrothermal simulation tool called hygIRC-2D. In this study an in-fill type wall was considered and hygrothermal simulations were carried out for the weather conditions of Shanghai. Investigations were conducted to determine the influence of the vapour barrier, exterior stucco cladding material and different types of sheathing boards on the moisture performance of in-fill walls. Additional simulations were carried out to determine the influence of air leakage on the moisture performance of in-fill walls. The outputs from the simulations were analysed with the help of a hygrothermal response indicator called RHT index. It was concluded that the design of the in-fill wall including a rain...

Structural Fire Performance of Innovative Moment-Resisting Connection Joining Steel Beams to HSS Columns

In this paper, experimental results of the structural fire behaviour of four large-scale steel frame test assemblies are presented. Test assemblies were made of HSS beams and columns connected together using an innovative extended end-plate moment connection configuration. Two different parameters were investigated, the connection end plate thickness and the degree of beam axial restraint. The fire performance of this beam-to-column configuration was compared to the behaviour of a commonly-used connection configuration with similar parameters and fire testing conditions. The newly-developed connection configuration behaved in a more flexible manner at elevated temperature than the regular configuration. In addition to improved constructability and pleasant appearance, the new connection configuration exhibits greater moment-carrying capacity and enhanced fire resistance characteristics.

Fire Performance of Corrosion-Damaged Reinforced Concrete Beams

This experimental study examines the effects of fire on corrosion-damaged reinforced concrete beams. Nine beams were cast with the same external dimensions and amount of reinforcement. Corrosion was induced in the beams by a constant current source. The beams were tested at constant service load while being exposed to the CAN/ULC-S101 time-temperature curve. The results indicated that the deflection of reinforced concrete beams increased during a fire exposure as the level of corrosion damage increased. The corrosion products within the pores of the concrete provided a limited insulating effect on the heat front penetration through the concrete cover. Temperature differential developed at the steel level was shown to help delay failure of the beams by the development of the axial thrust force. A major factor affecting the performance of corrosion damaged beams during a fire exposure was the ability of the concrete cover to remain in place.