Building Services Engineering Quiz

Introduction to Fire Engineering

• Course code: CIVL3811
• School of Civil Engineering, Faculty of Engineering, The University of Sydney
• Focuses on engineering design and construction related to fire

Overview

• Why fire design? Examines tragic building fires in Australia (e.g., The William Booth Memorial Home, 1966, 30 deaths), and World Trade Center (WTC) Collapse (2763 deaths).
• Progress of fire in a building Covers ignition, growth, fully developed, and cooling phases, including factors like ventilation, thermal energy transfer and material properties.
• Concrete behaviour at high temperature Discusses how concrete properties change at high temperatures.
• Fire Limit States and Fire-resistance Period Explains how structural elements are evaluated for fire safety based on limit states like strength and insulation. Fire spreading, integrity, temperature increase impacting materials, and ignition and time factors are considered.
• Design for the Fire Resistance Explores AS3600-2018, requirements for fire-resistant concrete members and standards to meet.
• Fire Protection in Buildings Covers active (e.g., sprinklers, alarms, fire hydrants, hose reels) and passive fire protection (fire-resistant walls, floors, ceilings, isolated stairs).
• References Provides details citing several industry publications and websites (e.g., ABСВ).

1. Why Fire Design?

• A tragic toll Details Australian building fires and casualties - illustrating the importance of fire design.
• World Trade Centre (WTC) Collapse Details the WTC collapse due to fire and the consequences, emphasizing the importance of resisting fire and understanding how structures behave in fires. (64 m², 411m above street level, 2763 deaths)
• Building Design (WTC) Expands on the design of WTC towers: weight, wind load, "tube-in-tube" design, (500,000 tons, 225 km/h hurricane, 5,000 tons).
• Weak Points Emphasizes the importance of angle clips and structural integrity to resist fire. (700 Pa & 1,300 t)

1. Why Fire Design? Control

• Fire in a concrete building Explains damage, loss of contents and loss of life caused by fire in a concrete building.
• Reducing damage Methods to decrease fire damage in concrete buildings include design, layout and fire protection.

2. Progress of Fire in a Building

• Ignition Requires sufficient energy, oxygen, and combustible material.
• Growth Air ventilation fuels the spread, thermal energy transferred by radiation and convection. Hot gases build up causing fast spread (flameover).
• Fully developed Very high ambient temperatures and the fall of elastic modulus, yield strength of reinforcement, and spalling (breaking off) of concrete cover.
• Cooling Fuel sources deplete, and the temperature decreases.

4. Fire Limit States and Fire-resistance Period

• Fire-related Limit State Explores strength, fire integrity (resisting fire spread), and insulation.
• Strength Load capacity reduces and member cannot carry sustained load.
• Fire integrity Focuses on preventing fire spread across the structure.
• Insulation Details how the temperature on the outside of a fire separating member reaches a certain temperature in which combustion may ignite a combustible material.

4. Fire Limit States and Fire-resistance Period (FRP)

• Structural design objective Achieving sufficient time for evacuation and initiating fire fighting procedures.
• Factors affecting FRP selection Use of the building, type of construction, and location (e.g., commercial/business zones).

5. Design for Fire Resistance

• AS3600-2018, Section 5 Requirements for reinforced concrete members to meet fire resistance.
• Design procedure based on AS3600 Addresses minimum cover sizes and limits regarding beams, columns, and slabs.
• Clause 5.8 Increasing fire resistance period using insulation materials.
• Design Performance Criteria A concrete member must have a fire resistance period (FRP) for structural adequacy, integrity and insulation of not less than the required level (FRL).

5. Design for Fire Resistance (Definitions)

• Axis Distance (CI 5.2.2-AS3600) Nominal value; distance from center-line axis to the nearest fire surface.
• Average Axis Distance (CI 5.2.1-AS3600) Average axis distance determined, considering layers reinforcement with different characteristic strength and cross-sectional area.

5. Design for Fire Resistance (Beams)

• Fire Resistance Periods (FRPs) Deals with the structural adequacy of beams.
• Beams (CI 5.4-AS3600) Examining structural adequacy according to the exposed surfaces to fire.

5. Design for Fire Resistance (Beams Incorporated in Roof or Floor Systems)

• Simply supported beams Follows procedures based on relevant table or figure (e.g., Table 5.4.1 (A), Figure 5.4.1(A)).
• Continuous beams Follows procedures based on relevant table or figure (e.g., Table 5.4.1 (B), Figure 5.4.1(B)).

5. Design for Fire Resistance (Beams Exposed to Fire on All Sides)

• Simply supported beams Follow procedures based on provided table or figure( e.g., Table 5.4.1(A) or Figure 5.4.1 (A)).
• Continuous beamsFollow procedures based on relevant table or figure (e.g., Table 5.4.1(B) or Figure 5.4.1 (B)).

5. Design for Fire Resistance (Slabs)

• Fire Resistance Periods (FRPs) Details the structural adequacy of slabs, categorized by type(one-way slab etc.).
• Insulation Focuses on slab effective thickness exceeding the limits in given table(Table 5.5.1).
• Structural Adequacy (CI 5.5.2) Solid and hollow-core slabs supported on beams or walls and the one-way ribbed slabs are considered.

5. Design for Fire Resistance (Slabs) Table 5.5.2(B)/(C)/(D)

• FRP for structural adequacy (min) Table for determining the fire-resistance period of slabs, including values for simply supported slabs and continuous slabs.

5. Design for Fire Resistance (Slabs) Example 2

• Slab Thickness and Cover Calculates minimum thickness of slabs based on determined FRPs (120 minutes).

5. Design for Fire Resistance (Slabs) Solution

• Solid and hollow core supported slabs on beams or walls Proporting slabs based on the average axis distance to the bottom reinforcement and checking that that distance is not less than the appropriate value in Table 5.5.2 (B). Slabs using insulation materials are assessed.
• One-way ribbed slabs Compliance with Clause 5.4.1 and ensuring appropriate axis distances are met, according to the relevant Table (Table 5.5.2(B));

6. Fire Protection in Buildings

• Passive Fire Protection Systems Covers components like fire-resistant walls, floors, ceilings, and fire-isolated stairs.
• Active Fire Protection Systems Includes mechanical systems (e.g., fire alarms, sprinklers, hydrants, fire hose reels), operation, and design features.
• Benefits of active fire protection systems Possible relaxation or reductions of the passive requirements may be accepted depending on the active fire protection systems installed in the building.
• BCA Structure Describes components/elements of the BCA (Building Code of Australia) fire compliance: Mandatory, Performance, Deemed To-Satisfy, and Alternative.

6. Combustion and Fire Spread

• Factors influencing combustion Removal of these factors (e.g., oxygen, heat).
• Role of water An effective fire-fighting medium.
• Fuel, Oxygen and Heat The intensity of a fire depends on the presence of fuel sources.

6. Fire Transfer/spread

• Types of Fire Transfer Focuses on conduction, convection, and radiation, explaining how heat transfers through these mechanisms.

6. Hints for construction of buildings

• Steel in concrete How steel loses strength and impact of temperature rise.
• Windows/glass Transparency to radiation and how fire spreads.
• Hazards in buildings on fire Focuses on hazards to occupants, contents, structure, and nearby buildings.
• Fire compartments Division of buildings into smaller compartments for structural stability.

7. Class of occupancy (NCC)

• Fire hazard The class of occupancy indicates the potential risk either to people or to property based on the buildings use type.

8. Fire Resistant Construction

• Fire resistant aspects Evaluates aspects of buildings, including the walls, floors, roofs, and columns, in terms of their endurance against a fire affecting the building's contents. Types of construction (NCC A, B, C) are part of analysis
• Fire Hazard Analysis Analyzes buildings based on classification, number of stories, and effective height to ascertain fire resistance levels, and to identify fire protection necessities for elements that could increase potential fire hazards.

9. Active Fire Protection Systems

• List of Active Fire Protection Lists common systems used to respond to a fire, which include; portable fire extinguishers, water supplies, smoke and heat detectors, fire hydrants and hose reels, and sprinklers.

10. Water Supplies

• Fire hydrant systems Normal method for major buildings.
• Fire hose reel systems Additional method frequently used.
• Sprinkler systems Automatic fire protection system.
• Domestic water supplies Used when water isn't readily available via mains or hydrants.

11. Storage Tank

• Elevated storage tanks for building water pressure from top of building required for buildings higher than 25m.
• For building heights greater than 12m above street level, a pump is required to boost the water supply.

Test your knowledge on fire-resistant performance, insulation, and structural design for slabs. This quiz covers various aspects of building services engineering, including fire limits and reinforcement techniques. Perfect for students and professionals in the civil engineering field.