Fires, Building Materials, and Methods - Case Study Example

Name : xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx Tutor :xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx Title : Fires, building materials and methods Institution : xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx Date :xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx @ 2011 Fires, building materials and methods Introduction Many ways of fire escape should be incorporated in the design of such building to provide escape routes in case of fire. Fire fighting equipment should also be provided at suitable locations just incase they are needed in the course of the life of the building. A number of fires have been witnessed around the world in the last 20 years. Most of them have been considered to be bad fires that resulted in heavy losses and deaths on the side of those involved. This study contains an analysis of fires in Italy, Spain, the UK and Canada which occurred after 1990. It also contains various building methods, materials and fire safety concerns that would be considered on an upcoming 40 storey building in Manchester City. Case Study 1: Windsor Building Fire in Madrid, Spain On 12th February 2005 a big fire broke in Windsor building in Spain. It was so severe that it was compared to the September 11 2001 fires in America. Windsor tower or Edificio Windsor as it was known was made of concrete with a central core made of reinforced concrete. The floors of the building were made of waffle slabs with the support of the core made of concrete. At the time of the fire the building was under refurbishment which was expected to last for 3 years (Dave 2005). Main works going on at the time were creation of a cladding system made of aluminum, sprinkler system, boarding system fire protection to steel columns all around the building and spray fire protection to steel beings in the inside of the building. Refurbishment was done on every floor from down toward the top. At the time of the fire, fire protection had been done for steel work up to the 17th floor. Part of the 15th and 9th floors was still undone and also the gaps in floor and cladding system were not filled up with fire resistant material. Fire stopping to fire doors on vertical shafts and voids was also not done (Brindle & Kerr1997). The original design of the Windsor building structure was in compliance of the building codes of Spain in the 1970s. During those times those codes did not demand that a building should have steel work fire protection as well as sprinkler fire protection in the entire building. Consequently there had been no protection for the steel work and no sprinkler system had been installed. There was also no stopping for the gaps existing between floor slabs and original cladding (Presley 2005). The tower’s floors were done in open plan concept and there the compartments of the fire just went from one floor to the other. Vertical compartmentation was not achievable because there was no system for fire stopping between floor slabs and original cladding. People believed that the fire resulted from a short circuit at floor number 21. Other sources stated that it might have been an arsonist attack. Form the 21st floor it took the fire only one hour to spread to all floors above floor 21. It also went down up to the third floor within a few hours (Brindle & Kerr1997). The fire spread easily to other floors because there were no measures for fire fighting like automotive sprinklers and the use of the open plan system of floor making on the building with floors occupying 1000m2. Another contributing factor to fire spread was the lack of measures for vertical compartmentation in floor openings and façade system. This fire affecting many floors as well as the buckling of steel columns with no protection on many floors is believed to have caused the floors on top of the 17th floor to collapse. Fire protection was complete on steel works under floor 17 apart from the 15th and 9th floors. When this fire descended below floor 17 those perimeter columns that had protection on them were spared (Presley 2005). Those with no protection, specifically on the 15th and 9th floors buckled because of the fire. Luckily no structural collapse was caused. Those loads which were supported by the buckling columns were spread out to the other concrete walls. Reinforced concrete, transfer structures, columns, central core and waffle slabs were not affected much by that heavy fire. The redundancy and integrity of the parts of the building that remained gave the building some stability. Steel conducts heat well while concrete conducts heat poorly. When there is fire the steel frames carry heat from the places of high concentration to the rest of the structure. Because the fire does not destroy the bigger structure the conductivity keeps the frame temperatures lower than the temperature of the fire. However it does not happen the same way with structures which have reinforced steel because concrete does not conduct heat very well (Brindle & Kerr1997). The conductivity of heat by the rebar within the concrete is reduced by the embedding concrete matrix and the small mass. When fire is severe it can result into concrete spalling but this cannot happen on steel. The reason for this is that the amount of latent moisture in concrete is very small and it turns into steam under the heat. It is therefore possible for a big fire to destroy a structure made of concrete. Structures with steel frames are only threatened by fire if the temperature of the steel goes up to the extent that failures result. The fire on Windsor building shows that big fires that can consume a building when allowed to burn for several hours can cause several building parts to collapse especially those without strong steel supports and without fire protection. It is also evident that the building parts collapsing do so partially and gradually (Presley 2005). Case Study 2: Quebec City Armory Fire (Canada) The Armory building in Quebec City was razed down by fire on 5th April 2008. The old building whose construction dates back to 1884 was constructed to serve as a reserve unit for the Canadian forces. At the start of the fire there was no body in the building meaning there were no people injured. A bigger part of the building went down after 2 hours of burning. The Armory building was one of the oldest in Quebec City and thought to be one of the most beautiful structures prior to its burning (Brokaw 2008). The building not being a high rise one was built with bricks and some pillars within its structure to give support to the material above. Brick is a bad conductor of heat and may not have given the fire easy time top spread through the wall. It took about two hours for the structure to collapse according to police. However the bricks being too old and having been joined together by concrete had lines of weakness in them. Concrete when exposed to fire loses the structural water within it and decomposes easily even though it is a bad conductor of heat. The building was not made with the present technology and lacked fire extinguishers and other equipment needed in time of fire (Taranath.1984). The fire could not be controlled in good time even though there were many fire fighters at the scene together with trucks. This was because the spread of the fire to the most vulnerable and highly flammable parts may have taken a very short time. This can be explained by the fact that the building was not built with fire proof material at any part of its structure. The fire caught the roof easily given that the materials used were old and easily destroyed especially by fire. The wooden ceiling under the roof was also instrumental in increasing the speed of spread of fire (Brokaw 2008). Case Study 3: Windsor Castle Fire in UK In November 1992 fire razed the Windsor castle situated in the West of London in England. Among the inhabited castles it was one of the largest and an official residence for Queen Elizabeth II. The building was severely damaged with some historic sections on the building suffering destruction. At about 11:33 am the fire broke out in the private Chapel of the Queen. It was started by a spotlight which lit a curtain. The alarm sounded in the fire brigade watch room. The fire site was indicated on the big grid map serving the whole castle by a light. At first only the Brunswick tower was shown but later a light showed that other rooms close by had been affected Owens et al (1994). Within a short time the fire reached the biggest state apartment called St George’s hall. Since 1973 the entire Greater London had been with only ‘one 30 appliance fire’. After another 1 hour the roof of the building collapsed. 2 hours later the Brunswick Tower floors collapsed. The fire then concentrated there. The fire got concentrated in the Brunswick Tower and caught its roof which was forced to collapse later. The fast spread of the fire can be attributed to the failure of the building to have fire stopping within its cavities as well as roof voids. The Castle’s fabric registered the biggest loss. The fire spread far because of the false roof on St George’s Hall as well as the ‘voids under the floors for coal trucks’. The fire burnt the Chester Tower making many ceilings to come down. The wall of St George’s remained intact as part of it was not damaged (Smith & Coull 1991). The parts which were severely devastated were the Dining Room of the state and the Grand Reception Room. More than 100 rooms in the Castle were affected by the fire. The building had a sizeable part of it made of timber and the card board ceiling which fuelled much of the fire. So many things within the confines of the room were destroyed. These things served as fuel for the fire making it to move faster to the other parts that had not been affected initially. The Castle was an old building and its design did not have the current features of modern buildings where emphasis is placed on fire risks. The structure of the building therefore did not have fire proof material to reduce the spread of the fire. The building material used was easily burnt (Owens et al 1994) Case Study 4: Fire in a Naples Italy Building On 5th November 2009 one building in Naples a historical center in Italy was damaged by fire which started at round 2.00 pm. The building was used for residential purposes and it was concluded that the fire started as a result of a problems with electrical appliances in a third floor apartment bedroom. Those people found staying in the building at the time of the fire escaped. Due to this they were able to facilitate the process of extinguishing the fire. However due to the fast speed of the fire which was growing from one level to the other it became impossible for it to be extinguished. Fire fighters saved a woman with her five children (Sabagh 1991). This fire grew very fast because it was not fought immediately when it started. Probably the people in the building had no knowledge of fire fighting. Again there was no fire fighting equipment like fire extinguishers which could have been used quickly to prevent much damage. The fire was fierce since it had much fuel from the flammable material in the residential rooms. A lot of domestic equipment and material that catch fire very easily were blamed for giving strength to the fire (Sabagh 1991). The construction of the building was not in accordance with the current building standards in Italy. As a result fire proof construction materials were not used in the construction of the building. The reason for this is that at the time of construction of the building codes had not been developed to govern the construction industry. Opinion on lessons learned and recommendations Important lessons can be drawn from all the above case studies since all of them are fires that occurred under totally different circumstances. Most of the fires that have occurred represented by the above case studies became serious because of the speed at which they spread. Fires spreading at high speed are fueled by the kind of materials that were used in the construction of these structures. Some of them were old buildings that were not built according to the current building codes specified in the countries involved. Old buildings should therefore be renovated as soon as possible to ensure that those without fire safety designs are fitted with proper equipment for fire fighting (Brokaw 2008). Buildings that were constructed many years ago and have no fire safety mechanisms and systems should not be allowed to house people. They should either be demolished or renovated if possible. All buildings should be designed with fire safety in mind and the necessary fire fighting equipment and agents should be supplied at all times. The case studies featured in this paper are all serious case of fire that could have been avoided or managed properly. The impression that can be made from them all is that the fires were so fast that they could not be contained. All the buildings being constructed currently should be done carefully with the best technology to overcome and control fire incidences (Taranath 1984). Building construction methods and materials The 40 storey building expected to have a hotel and residential quarters must be built with the strongest materials which are also durable and relatively cheap since it going to house many people. It should also be erected with the best methods which can guarantee a structure that is resistant to harsh environmental conditions. It must also be constructed with materials which are most resistant to fire. The design and methods of construction should also be those that promote fire fighting whenever it occurs. Both the safety and economical aspects must be born in mind. As a result the materials to be used will have to carter for these concerns (Sabbagh 1991). Construction methods and materials Steel Almost all multi-storeyed buildings in Manchester city are built by use of steel. Otherwise they can be built with ‘steel composite frame construction.’ Steel concrete composites would be suitable for building with 100 storeys or about there. Steel comes from the alloy of carbon and iron. It is a very significant material for construction and engineering. Steel has physical properties like flexibility, durability as well as strength which are very necessary in a 40 storey building. In addition it is a very sustainable material (Smith & Coull 1991). Of all the materials used in building steel has the highest weight to strength ratio. Steel is easy to join and form. Steel is light, dimensionally stable and strong at the same time. As a result it is suitable for construction of storey buildings since it can withstand earth quakes and hurricanes. Steel is easy to use in construction since it requires a simple small foundation and causes work to go faster. It will therefore help reduce the number of days used in the construction. This may help to reduce construction expenses (McCormac 1994). Concrete Concrete is a man made material used in construction. It is made from the mixture of fine aggregate or sand, cement, coarse aggregate like gravel and water. These components are normally mixed in certain required proportions. In the mixture only water and cement are active. Reinforced concrete can do very well when used in the construction of the 40 storey building. Reinforced concrete is made from the normal concrete which is poured around a grid work of steel rods. These rebar or steel rods provide strength to the concrete so that it does not bend in times of strong wind. Concrete is very strong even when exposed to the forces of compression (Chew, Michael & Yit 2001). Stronger concrete when needed can be made when some very fine particles are added to the normal ingredients of making concrete. Concrete has a high compressive strength but has low tensile strength. Consequently concrete used for parts that are exposed to forces of twisting, stretching and bending like walls and girders must have steel reinforcement. The frame of the tall 40 storey building will be covered by other materials which will give it a beautiful finish. Cladding will be done with glass, aluminum, stainless steel. Where necessary other parts can be covered with masonry materials like granite, marble and limestone (Sabbagh 1991). ICFs ICFs: One construction method that is suitable for this building is the Insulated Concrete Forms. ICFs are hollow structures made like blocks. They are stacked together in the same way as bricks and then concrete is filled in the hollows. The forms form insulation material on the wall. Less concrete is used and the wall created has better insulation capacity. Many of the ICFs are made from virgin polystyrene although one type called rastra is made of recycled polystyrene. The ICFs will be applicable on all the walls of the building; it will be more advantageous if they are used on underground basements because of their high capacity of insulation (Sabbagh 1991). Strategies of design for fire safety The best buildings for the safety of people are those that incorporate the right strategy for fire protection. In order to ensure that there is safety for the many people who will occupy the 40 storey hotel and residential building, the design of the structure must consider fire safety. In the design of the building there should be included: Means of Escape and Evacuation Strategies Under this, the construction process will involve the determination of the quantity of stair cases and suitable travel distances. To be considered under this as well is the method and strategy of evacuation whenever a disaster occurs. The design of the building should be done in a way that it will be easy to evacuate fire victims and that fire fighters can easily access various parts of the building without much difficulty (Taranath 1984). Structural Fire Engineering: This is aimed at maximizing the fire protection capacity of the structure. With the input of architectures it amounts to an effective but passive system of fire protection. The structural engineer produces the best design with the ability to provide safety from fires. In the construction of the structure, materials that help to resist fires are chosen carefully and used in the building (Michael 1987). Fire Compartmentation Strategy Sabbagh (1991, 130) explains that this strategy of fire Compartmentation provides for the creation of wide open areas as well as the achievement of reduced construction expenditure as much as possible. The safety levels of the building are not compromised in the process. It is based on dividing up the building to form discrete zones of fire. It delays fire spread and minimizes damage while confining the fire in the place it started. Stair cases are separated from landings and halls. Voids should be filled in order to increase compartmentation. External Fire Spread The spread of fire externally can be reduced through external wall construction as well as making separations between walls. External fire spread is also preventable through fire protection done on the sides of the building facing each other. The spread of fire externally can be reduced when the outside walls of the affected building have materials that resists ignition by fire from an external source. The walls should also have very few unprotected openings so that the passage of thermal radiation to adjacent buildings is limited (Chew, Michael & Yit 2001). Need for Smoke control In case of fire a lot of smoke will be produced. Smoke is dangerous in fire situations since it causes death when inhaled. It also causes lack of good vision since it scatters light or may absorb it. In such kind of a situation the people caught in the building by the fire may not be able to read the escape signs and routes. The possibility of occupants escaping is highly reduced or even eliminated. Smoke results in irritation of the eyes and the respiratory tract. This is caused by the various chemicals in the materials being burnt. Asphyxiant gases like carbon monoxide, hydrogen cyanide and carbon dioxide are likely to cause death because of their toxicity. Since the building will have 60% of it being used as a hotel, it will have big enclosed spaces and voids (Chew, Michael & Yit 2001). Smoke control should therefore be given priority especially in rooms with reduced ventilation. These big spaces can make it easy for hot gases and smoke to move over a large distance from its source. The hotel space is likely to have a very big number of people as well as materials that are easily combustible. It follows that smoke must be controlled in its production and transport. The control of smoke through a suitable smoke management system is necessary since it will provide a safe way of escape (Taranath 1984). This can be accomplished through the separation of the hot gases full of smoke and the people escaping from the building. As smoke control reduces the ability of the smoke to spread and heat up the building it provides an avenue for fire fighters to access the affected parts of the building (Brindle & Kerr1997). Sustainable Energy Technologies Technologies for energy conservation are necessary and will be applied in the construction of the building. It is necessary for sustainable energy technologies to be used as a way of protecting the environment and avoiding unnecessary wastage of energy and other resources. Therefore all the gadgets and equipment to be fitted in the building will be as eco friendly as possible. Equipment that does not consume a lot of energy such as energy saving bulbs is highly recommended. Technology such as solar heating will be necessary in order to cut down on the use of electric energy (Brindle & Kerr1997). Passive solar heating technology will help in cooling, day lighting and heating. Carbon control technologies will also be incorporated in the design of the building since carbon forms dangerous oxides. Its production should be minimized. In the event of fire carbon can combine with oxygen in low quantities to form a toxic gas called carbon monoxide. Carbon dioxide can also be produced when carbon combines with excess oxygen. Carbon dioxide is a green house gas which contributes to the global green house effect that result in the escalating global temperatures. It is therefore dangerous to environmental conservation (Chew, Michael & Yit 2001). Recommended Fire Extinguishing agents There are so many agents that can be used in the extinguishing process of fire. All these are applicable in fire incidences but people must be trained to use them. The most effective fire extinguishing agents I can recommend for this building are the water fire extinguishers, foam fire extinguishers, powder and wet chemical fire extinguishers. Water Fire Extinguishers Water based fire extinguishers should be kept in the building to quench fires with a lot of burning paper, soft furnishings and wood. It tackles ‘class A fires’ because the water is easily soaked up by the material and cools it in the process of putting off the fire. This agent is advantageous because it does not have dangerous chemicals which can harm the people using it. Unfortunately its capacity to fight fire is not very high. This is usually overcome by having large heavy fire extinguishers which is another disadvantage. It is also risky to use water since it is a conductor of electricity. People must take care when using it around exposed electricity cables (Owens & Knowles 1994). Foam Fire Extinguishers This is also known as ‘Aqueous Film Foaming Foam’. It forms a smothering foam film that prevents the fire from getting oxygen. This foam has a number of advantages which make it suitable for its job. This foam penetrates some pervious materials and as the water in the foam evaporates the material is cooled. The foam makes a carpet of foam on liquids such as petrol when they are on fire (Owens & Knowles 1994). These extinguishers are good for flammable liquids and also in places where carpets and soft furnishings have manmade fibers which easily liquidize when there is a lot of heat. Foam extinguishers can be used where there is electrical equipment. The disadvantages of this foam are also obvious. The use of this foam on electrical equipment may seriously damage them. The foam also has powerful carcinogenic additives which make cleaning after the fire a dangerous process (Smith & Coull 1991). Powder Fire Extinguishers They are also known as ‘ABC powder extinguishers or dry powder extinguishers’ and are important in quenching class A,B,C fires. Their advantage is that they have a high capacity of fighting fire. However this powder is disadvantageous since it has no ability of soaking up the burning materials and therefore does not leave behind any cooling effect to reduce the temperature of the fire. This is dangerous since it can make the fire to re-ignite if it is not extinguished properly. It is also dangerous if the powder is inhaled in the process of fire fighting. After using the powder it is hard to clean up the place because it easily damages soft furnishings, computer drives and carpets. ‘BC rated powder fire extinguishers’ are not good on burning solids and should not be used (Taranath 1984). Wet Chemical Fire Extinguishers These will be very useful in the residential area since they are effective on kitchen fires or Class F fires where burning oil as well as ‘deep fat fryers’ are involved. These extinguishers have along lance that makes it possible to lay a lay a cooling foam layer over the hot burning oil. They are also applicable on Class A fires. However their one disadvantage is that their power for fire fighting in cases of general risks cannot be said to be strong (Brindle & Kerr1997). Blankets Blankets should be purchased and kept in strategic places within the building especially in the residential premises and specifically near the kitchens. They can also serve in the hotel kitchen. Blankets are effective when used for covering the victims of fire. When a person is covered wholly with the blanket it cuts short the supply of oxygen to the fire (Smith & Coull 1991). Conclusion Fire is a dangerous thing whenever it occurs in a building. In some cases death has occurred as a result of people being trapped in burning buildings. Modern constructions must incorporate proper fire safety strategies to ensure that the safety of people is guaranteed in case of a fire in these buildings. Fire extinguishers should be installed in every building to help in the initial efforts of fire fighting in the event of such an occurrence. Fire and Rescue establishment are the primary enforcers and have a legislative task to enforce the necessities of the legislation. Each individual should be responsible for his own safety as an individual one should carry out the required measures to make sure there as safe and incase of fire they will be able to ensure there safety this can be done by ensuring that one has fire safety cylinders in the house and in case of fire he can be able to use them there are also other safety measures. (Kidd,1998).there are other special precautions ,required in houses and work place like keeping of combustible liquids in the process areas ,workrooms laboratory and other working areas ,the rooms should also be ventilated to dilute and remove flammable gas ,making use of equipments that may not act as source of ignition ,use extraction systems to be able to remove flammable materials like wood dust The materials used to construct the buildings should be as fire resistant as possible to prevent fire from spreading to other areas of the affected building. Building and construction technology for modern buildings should be in line with the recommended codes of building in various countries. Old buildings should be properly renovated so that they can meet the current fire safety building standards to avoid risks of fire. This paper looked at a number of case studies on buildings that were affected by fires in Canada, Italy, UK and Spain in the last 20 years. It also has the construction materials, methods and fire safety strategies for building a 40 storey structure for hotel and residential purposes in Manchester City. Bibliography Presley, D. 2005. “Madrid tower designer blames missing fire protection for collapse”. New Civil Engineer, Madrid Brindle, S. and Kerr, B. 1997, Windsor Revealed: New light on the history of the castle. London: English Heritage. Brokaw, L. 2008 Frommer's Montreal & Quebec City 2009‎ Quebec Michael, D. 1987 How Skyscrapers Are Made. 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