Thursday, August 15, 2019
Computing in civil engineering proceedings of the 2011 ASCE International Workshop on Computing in Civil Engineering Essay
Studies of construction management address the phenomena of construction problems and explore the nature of construction technology. Manufacturing technologies are categorized into mass, unit and continuous process of productions. Construction technology is classified as a unit production through contrasting construction activities and fabrications. Although the efficiency of construction technology is low in terms of unit production, it is associated with benefits such as zero stocks and flexibility. This report provides a description of materials/techniques used in the current construction of modern domestic properties, industrial unit properties, their comparison and critical analysis of the performance of building structures. It also encompasses on the principles used by builders to perform their functions, characteristics and behaviour of internal materials used in the construction. People have been looking for efficient production systems since the industrial revolution. However, most projects are still built under traditional way of one-of-a-kind production. Application of IT in construction has also failed to produce the intended results. Therefore, nature of construction technology needs to be understood more in order to explain inefficiencies that are surrounding the technology and theory that solves the construction problems (Sarkar 2008). According to Daft (2004), technology refers to the tools, machines, actions and techniques used in transforming organizational information and materials (input) into products and services (output). 1.0 Construction technology à à à à à It involves the study of construction techniques to successfully achieve the design of the structure with the recommended specifications (Sabnis, 2011). It includes temporary work and study of construction equipment needed to facilitate the construction process. The recent trend is towards constructing taller and lighter buildings. In order to achieve such buildings, sophisticated equipment needs to be employed in the construction process. 1.1 Current construction techniques/materials à à à à à The current methods of construction provide important benefits to developers and housing authorities which reduces the emphasis of on-site activity. This criterion is important particularly in the time of increasing demand of an already stretched labour force. Any new implementation of doing things is faced with risks, but such risks can be mitigated through having good planning and project management. Yvette Cooper, a planning and housing minister quoted, ââ¬Å"people must ensure that the new homes they are constructing are affordable to the next generations.â⬠This report shows that it is easier to build cheaper and faster using modern construction techniques whilst keeping high quality of traditional methods. 1.1.1 Modern methods of construction (MMC) à à à à à Modern techniques of constructing houses developed as early as 1945 after WWII, it was used by most of the developed countries such as Germany during buildings fabrication after WWII. Later these techniques spread in many countries and they are commonly used in India during the construction process. As technology, construction knowledge and manufacturing processes increase so do the number of available methods of house construction increases to house builders. Modern Method of construction is a collection of new relatively construction techniques aimed at offering advantages over traditional methods (Altenbach, 2013). Conventionally, this is an area pioneered by self builders, mostly in terms of sustainable construction. As developersââ¬â¢ sticks continually to the proven construction techniques that satisfy buyer demand, self builders have been willing to research, try and invest something different so as to achieve individual homes that meet their need. In an effort of increasing housing demand, shortage of skills and the set targets by Code of sustainable homes, many governments are encouraging the house-building sector to develop and use MMC technique in an attempt to meet these challenges. Most of these modern construction techniques evolved from their traditional predecessors. Techniques such as structural insulated panels (SIPS) and thin joint systems with Air Crete blocks are part of the on going evolution of timber frame and masonry construction (Kuzio 2009). Other familiar techniques have developed in the larger scale commercial construction. This has brought alternatives with interesting qualities of house building. Development of steel frame systems and in-situ concrete techniques led to the development of insulated concrete forms (ICF). 1.1.2 Advantages of modern methods of construction Reduced impact on residents and effect of weather on production Controlled manufacture and reduced fuel consumption and disruptions as a result of fewer materials delivered. Reduced construction defects and time consumed. High quality buildings 1.1.3 Modern domestic properties 1.1.4 Illustrations à à à à à Larger construction components can be incorporated into either MMC dwellings or conventionally built. They are not full housing ââ¬Ësystems,ââ¬â¢ but they are factory made or site-assembled. This category comprises of the following components and sub-assemblies. This involves a series of assembled components and pre-fabricated ground beams to form quick and accurate foundations (Koerner 2005). These are pre-fabricated panels designed specifically for floor construction. Fewer on-site labour hours are needed per square meter of floor, and the reduced work at heights has safety and potential health benefits (Hearn 2012). It involves designed pre-fabricated panels specifically for pitched roofs. These panels are very stiff which are designed to leave the loft free of props and struts, thus allowing easy production of ââ¬Ëroomââ¬â¢ in the construction of the roof. These roof cassettes make the building become water weight more quickly than cut roof constructions or conventional trussed rafter. These are roofs assembled at ground level before the shell of the dwelling is constructed. It can be craned into place immediately the superstructure is in place hence creating a weather tight structure more quickly rather than assembling the roof in situ (Corum Scotland 2010). Factory made dormers are used to speed up the roof watertight making process. Pre-fabricated lightweight chimney stacks made from factories are mounted on the roof structure without using masonry flue, thus making them suitable for construction of a lightweight frame. These chimney stacks can accommodate flue liners hence functioning with combustion appliances. Wiring looms à à à à à Cabling systems are manufactured in a way that they can quickly be assembled with relatively unskilled labour. They are made of various lengths terminated with plugs that are plugged into sockets and other electrical items (Quinn 2008). Standards are critical steps from development and research to marketplace adoption. Today, many industries are faced not only with managing technological development march, but also with pressures of how to do so cost-effectively, efficiently and with environmental and public safety being in mind. The appearance, energy efficiency, component materials and habitable structuresââ¬â¢ environmental impacts have dramatically changed over the last few years. This is as a result of successful standardization of processes, new materials and technologies. This section provides a sample of more recently developed shows and construction technologies, which has been facilitated by provision of the needed standards by ASTM internationalââ¬â¢s technical committees. These standards have swept off technologies of new construction to the drawing board and into the currently built environment. A Buildingââ¬â¢s Skin à à à à à 5488940117475Exterior Insulation and Finishing Systems (EIFS) were used in Germany after WW II to resurface buildings that were damaged by the conflict ravages. They are lightweight, systems of multi-layer barrier that helps in keeping moisture from outer walls. With several components, from foam insulation panels fastened to the base and a substrate coat, to the finishing coat and reinforcing mesh, EIFS is a complex system with materials required to connect successfully for years so as to keep moisture at bay (Noble 2011). EIFS standards development has been the key role of ASTM international Committee E06 on buildingsââ¬â¢ performance since 1990ââ¬â¢s. Their subcommittee E06.58 on finishing systems and exterior insulation published its first EIFS standard, test methods used in determining breaking strength tensile of reinforcing mesh of glass fibre. This publication was for use in class PB finishing systems and exterior insulation, after it was exposed to sodium hydroxide solution in 2000. Stone masonry Veneer à à à à à 548894093980The design freedom and cost savings offered by the products of stone masonry veneer have led to their increased use in architectural projects. In comparison to natural stone, manufactured stone veneers can be precisely colored, reinforced with steel, and have a predictable and durable life. The appearance consistency of the manufactured products makes repetitive use of materials as a trim or ornament economically feasible. Additionally, older structures can be renovated with manufactured veneer stones that replicate the deteriorating stoneââ¬â¢s appearance (Gunn 2012). It is a technology in which sealant adhesives are used to attach the glass to a building. In the last 20years, structural glazing has experienced exponential growth. It has been in use in industrial construction and other city buildings all over the world. Wood-plastic Composites à à à à à Since 1990s, recycled plastic and wood waste has been used as environmentally friendly and economic alternatives for decks. Components such as cladding, railings, molding, siding and trim, door frames and window; and structures such as small park benches. Concrete, which have been in use for a long time in construction of roads and structures is developing in a way that make it less expensive, more varied, safer, easier use and even more environmentally friendly. For example, a self-consolidating concrete that flows into forms was proposed in 1980sââ¬â¢ theory by a Japanese scientist. It has recently become viable as it used in infrastructural projects around the world. It properties are achieved by applying high-range-water-reducing mixtures; it increases the total quantity of fines applying admixtures that modify its plastic state viscosity (Li 2011). The innovative building enclosuresââ¬â¢ design relies less on past successful precedents than use of building science. This is a result of changes in methods and materials resulting from building innovation technology. Earlier building enclosures were only expected to provide a degree of environmental separation and be durable, but the recent structures must address issues like day lighting, energy efficiency, fire safety, thermal comfort, and indoor air quality and carbon footprint (Grondzik 2008). In half a century ago, wall performance requirements were outlined which are now applicable to all components and enclosure systems. The following are the major considerations that were identified: Rigidity and strength Control of heat flow Control of airflow Control of water vapour flow Liquid water control movement Durability and stability of materials Fire, aesthetic considerations and cost Since the time of Hutcheon, additional objectives such as environmental impact consideration associated with building materials and methods and the need to provide secure and safe buildings have been adopted. The acceptable requirements of wall performance were implicit within traditional materials and methods of construction. With the modern building science advent, they have become more explicit in response to technological innovation. The table below summarizes the requirements of contemporary performance and their corresponding assessment parameters. Moderator versus separator à à à à à A critical principle used in building science involves the difference between moderation versus environmental separation. For example, fire and smoke control movement is a strategy that attempts to completely separate fire and smoke from the indoor environment. The approach employs a fire-related assembly that fully controls leakage of smoke by virtue of the construction of its airtight and in some cases, the air pressuresââ¬â¢ control between compartmentalized spaces. Moderation involves a strategy where the difference between outdoor and indoor severity environments is moderated within the tolerable threshold. For example, heat transfer control does not seek to minimize the rate to zero, but to a level that satisfies energy efficiency, comfort requirements, and the control of wetting/condensation. The following table summarizes the key control strategies for building enclosuresââ¬â¢ design, which is involved in moderation strategy. A review of the corresponding control strategies and physical phenomena indicates the control of moisture migration is of the most important control function that needs to be addressed by designers. Problems of moisture in buildings are common and vary broadly in consequences and types. These consequences range from cosmetic flaws to structural failure and in some cases the occupantsââ¬â¢ health can be affected adversely as in the case of mold growth leading to respiratory and allergic problems. 2.0 Range of construction forms 2.1 Provision and access of internal division of spaces within buildings à à à à à Service integration should be jointly considered by the architect/designer, service and structural engineers. The interface between the fabric and the structure together with the service installations can cause problems. These problems can be in terms of the need to have re-route services within the structural elements or the purpose of passing through those elements (Luraghi 2008). Both structural and non-structural integration methods should be considered. The following are some of the spaces and divisions that an architect needs to consider. They should be installed so as to provide access to a building roof. The installation and design of the anchorage and the attachment system for the ladders should be described in MMAH standard supplementary. Fuel-fired appliances should be installed in service rooms from the buildingââ¬â¢s remainder by fire separations with the fire rating resistance which is not less than one hour. A more than 600 mm high roof space needs to be provided with floor access immediately before the hatchway that is not less than 550 mm by 990 mm or by a stairway. It consists of duct spaces and ceiling, which is more than 600mm wide and 1200mm high, shall have inspection doors. It should not be less than 300mm in both vertical and horizontal dimensions placed so that the entire space or duct interior can be viewed (Kuzio 2009). A fabric is a material structure selection, engineering, proper design, installation and fabrication of all work together to ensure a sound structure (Foster 2010). The role of material in the structureââ¬â¢s performance makes the selection process important. This is true particularly with air-supported and tensile structures because their frames, as well as their membranes carry the load. Membrane materials à à à à à Fabrics are typically laminated and coated with synthetic materials for environmental resistance and greater strength. Most of the widely used materials are polyester coated or laminated with PVC, woven fiberglass that is coated with silicone or polytetrafluoroethylene (PTFE). Films, Meshes and other materials also have appropriate applications. Polyesters à à à à à It is the most frequently base material used due to its cost, durability, strength and stretch. They are coated or laminated with PVC films and thus they are the least expensive for long-term fabrications. Laminates consist of vinyl films over knitted or woven polyester meshes. Coated fabrics typically use a high-tensile, high-count coated fabric with a bondable substance at the base for extra strength. Lighter fabrics are commonly used insulated and acoustic liners suspended beneath an envelope of a structure. For long-term exterior application, heavier materials are needed: fabrics with top coatings of PVF or PVDF (Zhu 2011). These top coatings are responsible with providing a protective finish to withstand environmental degradation. Vinyl-coated polyester à à à à à It is a common fabric used when producing flexible structures, such as canopies, walkways, custom-designed awnings, smaller air-supported structures, tent hall and light member-framed structures (ManCuso 2012). Properties of building materials Group Properties Physical Shape, Density, Size, Specific Gravity etc., Mechanical Strength, Plasticity, Elasticity, Toughness, Hardness, Ductility, Brittleness, Stiffness, Creep, Impact Strength, Fatigue etc., Thermal Thermal conductivity, Thermal capacity, Thermal resistivity, etc., Chemical Corrosion resistance, Acidity, Chemical composition, Alkalinity etc., Optical Colour, Light transmission, Light reflection etc., Acoustical Sound absorption, Reflection and Transmission. Physiochemical Hygroscopicity, Swell and Shrinkage due to moisture changes 3.2 Comparison of materials/techniques used in construction à à à à à The use of steel in the residential construction and housing sector has grown rapidly over the last ten years. This has been facilitated due to the growing appreciation of the performance benefits arising from the nature of the off-site of the construction process, which is particularly important in mixed-use or urban buildings. Steel construction technologies of an off-site increase the speed of construction and improve the final quality of the building, and can add points to the Code for Sustainable Homes. The main steel market in this area is in multi-storey residential buildings, and mostly mix-use buildings. Domestic buildings versus industrial buildings à à à à à A building classified as domestic is one which an individual uses as a dwelling place and provides separate family living quarters for separate family units (Richardson 2008). On the other hand, building not used in connection with a residence and not located on the same parcel as a residence, it is classified as industrial property. Most of the industrial/commercial buildings have been using pre-fabricated construction such as ceiling panels, prefab wall panels, flooring system and plasterboards to create interiors of offices (Domone 2008). Prefab materials provide the option of buildingsââ¬â¢ customizing for specific needs such as water and fire resistance and soundproofing. However, individual owners of homes have not yet gained enough confidence with prefab construction. This increases its demand for commercial spaces and from large developers but use by individuals in their homes is yet to gain popularity. 4.0 Critical review of how building structures perform à à à à à Organization structure may be considered the organizationââ¬â¢s anatomy, providing the foundation in which the organization functions. Hall (1977) noted from simple observation that an organizational structure affects its membersââ¬â¢ behavior. The particular buildingââ¬â¢s structure is a major determinant of the peopleââ¬â¢s activities within it. Hall suggested two basic functions of the structure each of which may affect organizational performance or individual behavior within the industry. First, they are designed at least to minimize or regulate individual variationsââ¬â¢ influence on the organization (Brown and London 2000). Organizational structure is also the setting in which decisions are made, power is exercised, and organizationââ¬â¢s activities carried out. Van de Ven (1976) highlighted the structureââ¬â¢s importance both at the subunit levels and the organization for the performance of organizations. Conclusion à à à à à Construction technology produces goods and provides services at the same time. The construction process is having low predictability and is highly uncertain. Many intermediate items are integrated and created by human operations with low standardization, mechanization and automation. The benefits of construction technology include high flexibility, zero stock, and satisfactory social needs. As these benefits appreciated, industry that is responsible with construction should consider improving integration of construction job site activities. 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