The Advantages of Steel in Building Construction - Assignment Example

The Advantages of Steel in Building Construction Introduction The first tread towards the planning of a facility is to understand the specific requirements of the building and then enter into the design phase. The grounds on which the requirements are formed mainly comprise of number of occupants and the purpose of building. Once these are dictated by the client to the consultant then the consultants initiate the designing phase. The consultant encompass vast areas of construction technology, they include experts in architecture, structural engineers, electrical engineers and then the services engineers who are majorly concerned with the HVAC of the facility. Another aspect that can no longer be neglected is the environment, both inside as well as outside the building is to be considered and given high level of consideration in design and construction of the building. Latest advances in technology and high appraisal in energy has influenced the mind set of the client to select and use energy efficient products and design, even if they cost a bit more in the start but they eventually pay back their expenses. It is no longer a choice but a compulsion for designers and constructors to save energy as well as environment and at the same time it’s the client’s and his real estates adviser’s social responsibility to dictate these terms in the facility’s construction and have knowledge as well as encourage these technologies as much as possible. Requirements There are mainly two types of spaces that are to be constructed as the part of the establishment. The first part is the 12 storey Headquarter block whose height would be around 40m, this would be just a typical office building and the spaces would be designed in the similar manner. The second requirement of the client in the facility is of a showroom/ retail facility which is going to be constructed just in front of the main office block, this separate facility would be used for the display of different products and so the space requirement of this would be entirely different to that of the office block. The basic requisite of this space is that it should be a single storey and 35 m wide span, these attributes makes this part of establishment unique and this structure has to be designed accordingly. The third and the most governing requirement of the client in the construction is that the time for construction should be as short as possible and the facility should be brought into service in minimum time period and the last requirement which would dictate the construction and its techniques as a whole is that the facility should eco friendly at all its levels both during the construction phase and during the service life as well. To achieve all these requirement effectively, there are majorly three main grounds on which we have design, construct and operate the whole facility. The first and the foremost aspect that will govern the necessities would be the Structure of the facility and this would include the type of structure, the material that is going to be used and etc. It should be kept in mind that these attributes of structure dictates how much construction time is required which is of key importance in our project. The second ground on which we are going to analyze every thing is the Architecture of the facility; this would encompass the aspects of weather protection, cladding, exterior wall, etc. Then last but not the least would be the aspect of the Environment, the word might seems to be small but its covers a vast range of attributes of the establishment, this includes the protection of the atmosphere and surrounding during construction and when the facility is constructed then the maintenance of interior environment is of major concern. At the end of the day, what ever establishment you pursue it is of prime importance that you plan ahead and foresee all the future requirements of the facility, to avoid inconvenience and troubles in the future. Once you have planned and discovered the major requirements, then a good, effective and apt design can be produced and consequently every thing in the project is streamlined. Now the main grounds on which the construction and operation will carry on will be discussed in detail. Structure The two main aspects that will dominate the structure are the space requirement which will tell us the type of structure and the other will be material of construction of the frame. As per the requirement mentioned earlier, it can be concluded that there will be two types of structure that need to be constructed within the same facility. For the office building the most suitable structure would be a Pre-Engineered Braced Steel Frame and on the other hand the showroom which is to be constructed in front of the office would be a wide-span steel frame. The selection of two different frame is because of the showroom is to be made with 35 m wide span which is only possible in wide-span steel frames and for office we need maximum covered area in minimum base area. Then comes the selection of construction material, where steel is the most suitable choice available to us where as other options include concrete and timber. There are many reasons for this for the selection of steel, where the first and the foremost is basis is time. The time required for the construction of the steel building is very less, the time of construction of a steel building is 50 – 60 % less than that of the conventional on site construction (SFSL) which include concrete and timber requires a lot of carpentry before use . So we can save this time and bring the building to service sooner and generate revenue in the saved time therefore making the project economically more feasible. Then comes the issue of cost, where again steel is a most preferred material of construction as compared to concrete and timber. The reason for that is steel has a salvage value and your standing structure’s value increases with time as the cost of steel increase, the basic cause of this lucrative option is that steel member can be recycled by smelting them back to iron. Steel is 100% recyclable material without degradation and its recycling rate can go up to beyond 60% for the constructional steel in some countries (Haluk). Whereas the concrete has no salvage value rather you have additional cost when u has to reconstruct another building in place of the old one and the cost to transporting the old material. Another major aspect of steel is that it provides safer structure as compared to the alternative materials like concrete which show brittle failure on sudden and accidental loadings such as earthquakes and hurricanes. In addition steel shows early warning and is a ductile material consequently before complete collapse it gives a warning and some time for the inhabitants to leave the premises. Then steel is also a fire resistant material to a greater extent when compared to timber structure, therefore it can be concluded that the inherent properties of steel makes it the most preferred material when assessing on the grounds of protection of sudden failure and safety of inhabitants. Then another property of the steel is its impact to the environment. The steel beams and columns give more structural stability and strength in lesser space as compared to concrete and hence more service spaces is available. Then steel manufacturing is done off site which makes the process of installation more clean and dust free and eventually no pollution on site. If u are in a busy city and as we are aware that our project is in brownfield then steel is the option that can be executed with minimum disturbance as steel is manufactured outside and then brought to site and then fixed together with minimum noise pollution and there is lesser rush of traffic and people if steel is used. There are many other rewards that steel construction offer which might include lesser exaction and ground work as steel structures have high strength to weight ratio, higher quality of construction, lesser human resource is required, and many others . Architecture This aspect of the facility is going to be crucial as far as the usage of latest technology is concerned because there are a large variety of components that it encompass and then further there is a wide range options available in a single components. Architecture of a facility includes exterior outlook and interior spacing. The major contributing components in exterior of the facility are its architectural Cladding, Curtain Wall, windows, glazing and interior includes design that in cooperate space saving, passive solar heating and day lighting etc. The first to be included into the discussion would be Exterior Insulation and Finish Systems or EIFS systems. These are the high insulation, light weight wall claddings that are produced in a wide colour ranges. These systems are best suited for our steel structure as they can be applied over steel stud walls. The basic necessity that is fully provided by the high-performance EIFS is that it provides unparallel water drainage. Water drainage designs provide secondary weather protection and a means of draining moisture. The construction of this component is consists of few layers and every layer has its benefits. The innermost layer of an EIFS with drainage creates its greatest value when it is designed to act as an air barrier in addition to a water-resistive barrier. It has been shown by National Institute of Standards and Technology'(NISTIR 7238) that this technology saves upto 15% of energy in cooling climates and 45 % in hot climates. Then the Expanded Polystyrene (EPS) layer is one which provides the insulation and protects the underlying framing from expansion and contraction due to temperature change. The EPS layer of EIFS can be attached to sheathing using an adhesive, or with mechanical fasteners. Another advantage of EPS and EIFS in general is that it provides highly efficient exterior insulation. By placing all of the insulation outside the sheathing, the location of the dew point is is reliably moved outside of the wall cavity hence unparallel insulation is provided, this attribute makes this a versatile solution and can be used in almost all climatic conditions. Another major reward that is gained from this system is that it is a lightweight option when comes in comparison to others. These Lightweight cladding is generally designed to move with the structural frame and must be able to accommodate design drifts and this ability makes its most safe option in catastrophes like earthquakes and heavy seismic movement. There are many others advantages of the EIFS which include the outermost layer giving aesthetic flair, the effective cost benefits, the reinforcement by mesh and many others and this makes it the choice of the day as far as the exterior of our facility is concerned. This latest technology is used in many structures in the US and is under progressive development in the National Institute of Building Sciences. The adhesively-fastened EIFS cladding on the Hard Rock Casino in Hollywood, FL looks great, and is designed to withstand hurricane-force winds. The second major feature of the exterior of a facility is the windows and glazing. In recent times the glass technology has rapidly developed and now we have High-performance, energy-efficientwindow and glazing systems. Employing techniques like high-performance windows feature double or triple glazing, specialized transparent coatings, insulating gas sandwiched between panes, and improved frames. We can achieve many advantages which include heat gain and loss control, visual requirements (colour, glare and tint), it also provides the thermal comfort. The components of a typical window of the modern age are shown in the figure below. Factors affecting window performance (Courtesy of Energy User News) The modern advances in the glass technology has added to the purposes in its usage, now the latest glass industry in cooperates characteristics such as Window U-value, Window Solar Heat Gain Coefficient (SHGC), Glass Visible Transmittance (Tvis-glass). The U value of the window is the rate of transfer of heat through the window through the processes such as conduction, convection and radiation. Then SHGC tells us the extent to which the heat of the sun light striking is transferred through into the building facility. This attribute of the glass is very important for the HVAC system of a building and can be used to save energy as well. Then comes the Visible Transmittance, it is the percentage of visible light portion that pass through the glass and how much of the ultra violet rays are filtered, consequently the inhabitants can be protected from the harmful UV rays. At the end of the discussion the various recent technologies that are employed in glass industry would be mentioned. Performance information was calculated using Lawrence Berkeley National Laboratory WINDOW 5.2 computer analysis program Azurlite® and Sungate® are registered trademarks of PPG Industries Heat Mirror™ and California Series® are trademarks of Southwall Technologies LOF Eclipse® is a registered trademark of Pilkington/Libby-Owens-Ford Co. Solarscreen 2000 VEI-2M™ is a registered trademark of Viracon Note : The above table is taken from National Institute of Building Sciences and the exact specifics are given in referencing (Gregg D) Environment There are two types of environment that needs to be taken into account first is the Interior Environment of the facility and then the second is the environment that is impacted by the building’s construction and its affect to atmosphere and the surrounding. First we will discuss the technologies that are used to control and that affect the interior of the building. The major system that governs the interior of the buildings of the scale we have chosen is the HVAC system. The job of a HVAC system is that it controls the temperature, humidity, air quality and fresh air availability of the interior space of a facility. An efficient system is the utmost requirement of the day because its requires an immense amount of energy and fuel to operate, secondly it wears out earlier than expected if not used with optimization and consequently it needs replacement which is not a financially feasible option. So from this it is to be concluded that a good and technologically advance system is to be installed from day one so that there are no issues during its operations. As the name depicts the HVAC system consists of three disciplines of Heating, Ventilating, and Air-Conditioning and in addition there are control systems that monitor their performance and efficiency. The first system we are going to discuss is the heating system, in our targeted establishment we are going to employ Watertube steel boilers, these pass hot combustion gases over water-filled tubes which will convey the heat to the different zones and levels of the building, in addition these heating system would be coupled to the heating control system which will include Modulating flame system, this control system is adjusts the heat input of the boiler and consequently reducing on/off cycling of boilers and improving the efficiency of system. Further more the inclusion of Oxygen trim systems which monitors amount of combustion air to achieve high combustion efficiency, will make this almost an ideal heating system. Next comes the Air-Conditioning systems, where the two main components are the chiller and condenser. When we considering the chiller we have no other choice but to use Mechanical refrigeration chillers, in which we will use Centrifugal compressors, as they are the most advanced and energy efficient systems available. For condenser we are going to use Water-cooled condensers although they are costly as compared to other systems (Air-cooled condensers) but they are energy efficient and in addition do not use CFCs for cooling and pose no environmental issues. Along with these air conditioning systems come the control system where it is diagnosed that we use Variable speed drives which will give us higher performance of the chiller system and for the condenser we will utilize Integrated chiller plant controls for minimum combined energy cost. The third aspect of the HVAC system is the Ventilation Systems. Where it is suggested that we utilize Constant air volume (CAV) systems, although there are many other systems available but the choice of this system is done because a constant rate of air while varying the temperature of the supply air and as our building will be multi zoned and floored so this system will be the best. CAV systems with reheat, however, provide superior comfort in any zone. Constant airflow reduces pockets of "dead" air, and reheat provides close control of the space temperature. Coupling CAV system with an intelligent control system is now the next requirement, where we are going to use Direct digital control (DDC) systems using digital-logic controllers and electrically-operated actuators are replacing traditional pneumatic controls. In addition we are going to use CO2 based system as well, which will monitor the CO2 presence in the atmosphere and with its control system let in the fresh air if the percentage of CO2 is higher and it will also aid in dehumidizing the indoor environment. In the discussion so far we have discussed the latest technological system in HVAC which are going to be used. At the moment we have no other choice but to use them although knowing their environmental impacts and massive energy consumption. But we can employ other methods, procedures, arrangements and technology to aid the systems of HVAC. Consequently we can save energy, finances and have lesser impact on the environment. The first recommendation that I will make is that the spaces would be designed by the collaboration of architects, interior designer and botanist. They will incorporate all greenery and indoor plants into the interior environment of the facility, we will achieve numerous advantages which include production of fresh air and improving the Indoor Environmental Quality within the premises, giving a fresh and healthy atmosphere for the inhabitants and also saving in energy consumption of the hvac system. In addition if the client is comfortable with the green outlook of the facility then the building can also have a green roof and garden. Then technique that can be used is the passive solar heating, in this the architect and then later the engineer are dictated to make a structure and design it. The idea of passive solar heating is simple, but applying it effectively requires attention to the details of design and construction. There are four generic passive solar heating approaches: sun-tempered, direct gain, indirect gain, and isolated gain. We are going to use Sun-tempering is achieved through modest increases in south-facing windows. A tract builder's house typically has about one quarter of its windows on each façade with a south glass equal to about 3% the house's total floor area. Depending on the climate, a sun-tempered house or barracks might increase this percentage to between 5 and 7%. In this case, no thermal mass needs to be added to the basic design. Another system that can be used to improve the eco friendly attribute and carbon footprint of the facility is by making it self-sufficient in energy to a certain extend by using a new and latest technique of Combined Heat and Power (CHP) system. The waste heat produced by an engine generator can be used to power a heat-driven cooling system. A typical air-conditioning/refrigeration system use electricity to enable the cooling. But Absorption chillers use heat instead of electricity to enable the cooling. When Absorption chillers are integrated in a Combined Heat and Power (CHP) system, the needed heat to power cooling is supplied by the waste heat given off by the engine generator. Absorption chillers can be direct-fired or indirect-fired. Direct-fired chillers burn fuel to produce the heat required. Indirect-fired chillers use steam or hot water produced externally, such as from a CHP system. They are cost-effective when incorporated in a CHP system. The schematic diagram is as below Environmental Impact of Facility There are two phases of a project where the environmental impact is to be assessed; first being the construction phase and the second is the operations phase. Our proposed facility starts with a positive impact on the environment as we have selected a brownfield area for the development and reusing a covered space rather than using new land or a green land. After the land acquisition comes the stage of site clearance and excavation, where we have to take care that the waste material and demolition debris is dumped in right place and recycled to maximum. Then it is the construction stage, where we have to use such a material which is best suited and most economical. As we have discussed before as well that steel is going to be the basic material of construction. This choice will help us lessen the negative impact on the atmosphere and the surrounding of the construction site. Steel needs lesser material excavation and its almost dust free construction when it comes in comparison to concrete. Any steel waste produced during manufacture, such as off-cuts or turnings, are 100 per cent recycled into new steel. Furthermore because construction products are preengineered to the correct dimensions, there is very little, if any, wastage on the construction site. The steel construction has minimial disturbance, consequently this type of construction is preferred in busy urban areas such as the one given to us. Then we can have garden roofs which have Vegetated roofs. Can reduce heating and cooling by at least 5% Can double the life of a roof and can reduce storm water runoff by 50%. In addition the rain water can be used in the vegetation of these plants and those which are grown inside the premises of the building. References 1. Haluk Coskun (2002). THE ADVANTAGES OF STEEL IN BUILDING CONSTRUCTION REGARDING THE ENVIRONMENTAL IMPACTS OF BUILDING MATERIALS. Turkey: Eregli Iron and Steel Works Co. 4. 2. SFSL Steel Frame Structures Limited. (.). Steel Frame Structures Advantages and Benefits.. Available: http://www.steelframestructuresltd.co.uk/ab.html. Last accessed 18-12-2010. 3. Richard Martens, LEED AP. (09-14-2010). High Performance EIFS. National Institute of Building Sciences Available: http://www.wbdg.org/resources/hp_eifs.php. Last accessed 19-12-2010. 4. Gregg D. Ander, FAIA. (18-06-2010). Windows, National Institute of Building Sciences. Available: http://www.wbdg.org/resources/windows.php. Last accessed 20-12-2010 5. Capellaenergy. (2010). Combined Heat, Power, and Cooling Solutions. Available: http://capellaenergy.com/. Last accessed 22-12-2010. 6. Corus. (2010). Sustainable steel construction. Available:http://www.corusconstruction.com/file_source/StaticFiles/Construction/Library/sustainable%20steel%20construction.pdf. Read More