Appropriate Structural System of the Building - Report Example

Number APPROPRIATE STRUCTURAL SYSTEM OF THE BUILDING The principal decisions with regard to the structurerelate to the column layout, the foundation conditions, integration of the building’s services as well as the external wall finishes. An appropriate structural system will have to be decided. Certain structural principles will have to be used to determine the appropriate frame system for the building. This is a report of researched and analyzed structural systems for the determination of the appropriate system for the construction. Steel framing Steel framed structure have be very common structural form for most strong buildings as it can provide great flexibility. Today’s steel framed buildings have been designed on the principle of structure being an independent load bearing frame that carries both lateral and vertical loads down to the foundation of the building. The form of construction ensures large column free internal spaces creation that can be facilitated by interchangeable portions as well as by elimination of the external wall as an element of load bearing, it enables large window area development as well as curtain walling and cladding systems. Buildings that are steel made are able to provide accommodations for a wide range of functions as well as adapting to many different architectural styles. Steel frames are best used in multistory buildings which accommodate office developments, car park, shopping centers, hospitals, and schools and universities. Even though each building’s anatomy is similar, different requirements for services, column grid, as well as external and internal finishes may arise (TATA Steel, 2014). Steel structural system provides many benefits as follows: 1. Speed construction Steel constructions make use of pre-fabricated components, which are quickly fixed on site. Shorter periods for construction enables savings on site preliminaries, reduced interest changes as well as earlier return on the investment. Since the construction is in an urban area, speed construction will reduce disturbance to neighboring properties (American Institute of Steel Construction, 2014). 2. Flexibility and adaptability Steel framed systems that have made use of infill as well as separating walls are characteristically flexible in areas of their location as well as plan and are able to meet several of apartment layouts. They facilitate future reconfiguration to meet new demands as well as accommodate change of use. Modular systems could be dismantled as well as moved so that the value of the building is maintained (Clive, 2014). 3. Light weight Structures made of steel weigh halfway less compared to equivalent concrete structures and modular systems or light steel framing do weigh less than 1/4 of a concrete structure (Grouchie, 2014). 4. Fire resistance During constructions, one of the most important considerations is fire safety. Timber framing has diversely been affected by this. Steel construction happens to be inherently noncombustible and will reduce the fire load. 5. Quality and safety Off-sight pre-fabrication betters the quality through factory controlled production, as well as being lesser dependent on the weather and site trades. Using pre-fabricated components does reduce the site activity for construction of frame by almost seventy five percent, contributing substantially to safety in overall construction. 6. Environmental benefits Most intrinsic properties of usage of steel in constructions have a significant advantage to the environment. For instance, steel structure is one hundred recyclable, repeatedly as well as without degradation. High construction speed as well as reduced site disruption is a great benefit to the local environment. Fig: standard fine plate connections in steel framing (The free encyclopedia for UK steel construction information, 2014) One of the major shortcomings of steel is its thermo conductivity. It is more than four hundred times more conductive compared to wood. A wall that is steel framed has a general R value of 46% to 70 % of comparable wood framed wall that has the same cavity insulation. Increment of insulation from 31/2 ”to 51/4“in a steel farming will not increase the R value proportionally. For R value increment, it would be more effective to move from 16” O.C. to 24” O.C. or in other words, reducing number of places that are available for thermal bridging. Thermal bridging will occur when the steel will span from the outside right to the inside of the structures envelope. It may lead to high heating as well as cooling bills; requirement for more HVAC equipment: as well as condensation of moisture on the warmer wall side could lead to mold (Georgia Environmental Facilities Authority, 2010). At high temperatures, steel structures lose their strength, and are susceptible to fire Steel structures are also susceptible to to corrosion TIMBER FRAMING Timber framing as well as post-and –beam construction are approaches of constructing with heavy timber instead of dimensional Lumber for instance 2”*4”s. the traditional timber framing is an approach of building structures by use of heavy squared- off as well as carefully joined and fitted timbers whose joints have been secured by jointly fitted pegs or the large versions of mortise as well as tenon joints in the future. Just other structure frame systems, timber framing has its pros and cons. 1. Pros One thing that contractors will agree upon the use of pre-fabricated timber frame is quicker compared to brick and block construction. Most trades involved in building construction like plasterers and electricians are unable to start in exposed weather conditions so the interior need to be protected from weather. Such trades may start earlier where a timber frame has been constructed enabling early finishing. 2. Quality and construction ease Getting the frame up is the easiest part. The frame will be very accurately constructed hence quick and easy erection. 3. Thermal performance Insulation in timber frame will be contained within the structure depth hence a typical wall of timber can be more thinly compared to its masonry equivalent, for instance by 50 mm. At a time when a good insulation is obtained, amount of heat that is lost due to air leaking out of building becomes much significant. Frames of timber work better on this score since they are closed for prevention of moist air from reaching the inside of the building. 4. Sound and noise insulation Due to timber’s dead weight, there is an advantage in masonry construction over light weight timber. High sound reduction levels will be achieved by means of constructing two distinct walls, which have a structural break in between them. The gap may be filled with a sound absorbent quilt, for instance mineral wool. 5. Green construction Timber, unlike other building materials have a lot of benefits to the environment. It is renewable material unlike blocks and concrete, which are depending on raw materials for production. Timber usage as a building material does encourage the growth as well as expansion of forests. These forests will provide the supply that absorbs CO2 hence reducing global warming level (Rob, 2014). 6. Reduced construction waste enhanced by efficient controlled manufacturing, 7. Less waste on site with removal requirements, 8. Energy efficient if constructed to modern standards 9. Reduced site labor (Rob, 2014). Cons 1. Condensation risk Causes of condensation include warm moist air that is produced through space heating as well as activities like cooking and washing tools. Masonry constructions like cavity wall a prone to condensation where warm inside air has gone through most of the insulation. Condensation in timber frame-wall is not so casually treated and its prevention is a major concern. 2. Rot beetles This is rare for modern timber. However, external elements of timber like cladding as well as fascal boards are vulnerable to rot in a case where they are not well maintained. The actual frame may be well protected. 3. Fire Very obvious, timber can burn compared to steel and Masonry. This leads to the conclusion that a timber construction will not be safe. However, the progress of destruction level as well as injury or death in most house fires will be mainly determined by behavior of occupants, availability of smoke alarms fitted, or the flammability of the house contents among other factors. However, in a case where the frame is not well and correctly built, then it will be difficult to control a fire and more damage will happen. 4. Structure and robustness Timber has over time proven to be a strong durable building material. Timber frames that are well built will last for years. Timber building requires a lot of planning. For economy purposes, timber frame elements are designed and calculated carefully to facilitate usage of limited material as possible for required strength. Therefore, it is not clear to extend or alter an existing building or and the demolishing of a wall should not be carried out without consulting for structural advice (Owen, 2013). Other problems concerned with timber framing include: Traditional process of procurement, Additional design and engineering time, General drawings arrangement modification if they are based on masonry construction, Site quality control deficiency. Fig: timber roof joinery (Cochran, 2013) http://timberframehq.com/timberframeconstructiondetails/upper-king-post-joinery-detail/ Timber framing should be considered if: Building in winter(need for structural shell up quickly), Structure is to be set on a particularly poor ground, Heating expectations are that during winter heating will be frequently turned on and off, There is wish for promoting use of environmental friendly material, Major alterations will not be done on the buildings after it is built, Plan design does not include large structural spans, Site is quite constricted with access that is limited or/and space store materials There is a lot construction work intended to be done and, The site is timber friendly (Owen, 2013) Glulam (Glued Liminated timbe) Glulam Is a kind of structural timber product that comprises of several layers of dimensioned timber joined together with some durable structural adhesives that are moisture resistant. Through lamination of several small timber pieces, one strong and large member of a structure is produced from these small pieces. Such structural members are made use of in horizontal beams or vertical columns, and curved arched shapes. The product is readily produced in shapes that are curved and is available in different species as well as appearance characteristics so as to meet varied end usage requirements. Glulam maximizes the structural importance of the renewable resource which is wood. Due to their composition, huge glulam members may be produced from various small trees that are picked from second as well as third growth forest or plantations. The material does provide versatility and strength of the large wood chambers with no reliance on old growth dependent solid sawn timbers. Glulam reduces the amount of wood material used when compared to the solid sawn timbers through lessening the knots and other small defects’ negative impacts in every component board. : Columns- square, round and complex sections, Straight beams- glulam lintels, ridge, lintels, floor beams and beams, Tied rafters Tied arches, Glulam trusses, Curved portals Arched bridges, Domes and arches and Curved beams (Juan, 2014) Benefits of Glulam Glulam materials are able to provide the following; A product that is all round that could be used as floor or roof beams, bracing, column, decking as well as other structural components, Light weight material for instance it can be 1/6 compared to similar dimension re of concrete beam Green material that has quite low formaldehyde levels, Lower handling and transportation costs (Timber Structures, 2009), Glulam arches and beams are able to generate huge unsupported span areas, Easy to repair as well as install material, Material that can be customized to meet requirements, Production is on well managed forests aa well as certified to PEFC, Great insulation properties (Timber Structures, 2009), Durable material, May be manufactured in longer lengths as well as large section sizes, Can offer great properties for fire resistance and can outlast still beams while under similar fire conditions. They offer precise dimensions, since they are produced from seasoned timber (Juan, 2014). The main disadvantage of Glulam materials is that Swelling as well as shrinkage can lead to splitting as well as delamination of the entire beam. Handling of Glulam material Members of Glulam need to be handled with care to escape damage or reduced structural capacity of the material. Handling recommendations are as follows; While lifting, fabric sling need to be used, Chains should be used to avoid glulam surface damage, The material needs to be covered with a plastic to protect it from weather. The material should be protected until installation time unless it is require for exposed areas. The recommendations of the manufacturer have to be followed (Juan, 2014). Fig: Glulam frame sketch (Wilson, 2014). http://carpenteroak.com/inspiration-and-ideas/case-studies-oak-framed-extensions/greywings-case-study/ The following structural principals will be used to determine the appropriate structural system The building will have to be constructed safely to be able to carry the loadings applied. It must have adequate stiffness and strength to resist the loads applied due to wind and gravity. The structure’s function in resisting horizontal loads cause by wind and vertical loads caused by gravity will have to be separately determined. Primary floor loadings are due to the buildings self-weight as well as its occupancy. They are known as dead and superimposed (imposed) loads respectively. Floor loadings that are going to be supported by the structure will have two components: Dead or permanent that comprises of the floor’s self-weight plus that of supporting structure and also the weights of raised floors, finishes, air conditioning ducts, ceiling as well as equipment. Superimposed loading being the load the floor is likely to withstand at the time of its life and will also depend on the use (TATA STEEL, 20114). At times, floor components’ vibration could affect sensitive equipment or cause discomfort. The fundamental frequency of the system of the floor will have to be checked. The building will have sufficient lateral rigidity so as to resist the likelihood of wind loads. The building will be built based n forces of wind acting on external cladding are conducted to the floor forming horizontal diaphragms, shifting the literal load to rigid elements as well as the ground. The functional requirements of the buildings will determine grid of the column that will dictate spans where by the criteria of limiting will be rigidity but not strength. References American Institute of Steel Construction. (2014). Importance of Framing Selection. Retrieved 11 1, 2014, from aisc.org: https://www.aisc.org/content.aspx?id=3818&linkidentifier=id&itemid=3818 Clive, F. (2014). The Pros and Cons of Different Construction Systems. Retrieved 11 1, 2014, from homebuilding.co: http://www.homebuilding.co.uk/ Georgia Environmental Facilities Authority. (n.d.). Steel Framing. Energy Fact Sheet, 1. Grouchie. (2014). All About Steel Builldings. Retrieved 11 1, 2014, from steelbuildingstoday.blogspot.com: http://steelbuildingstoday.blogspot.com/2009/02/pros-and-cons-of-steel-buildings.html Juan, R. (2014). Glulam Classification and Uses. Retrieved 11 1, 2014, from about.com: http://construction.about.com/od/Wood-And-Plastics/a/Glulam-Classification-And-Uses.htm Owen, J. (2013). Pros & Cons of Timber Frame Buildings. Retrieved 11 1, 2014, from constructionchat.co: http://www.constructionchat.co.uk/articles/timber-frame-buildings/ Rob, R. (2014). The Advantages of Timber-Frame Building. Retrieved 11 1, 2014, from motherearthnews.com: http://www.motherearthnews.com/green-homes/timber-frame-building-zmaz04aszsel.aspx#axzz3Hnn7fDog TATA STEEL. (20114). Principal Construction. Retrieved 11 1, 2014, from tatasteelconstruction.com: http://www.tatasteelconstruction.com/en/reference/teaching-resources/architectural-teaching-resource/design/choice-of-structural-systems/structural-principles TATA Steel. (2014). Construction. Retrieved 11 1, 2014, from tatasteelconstruction.com: http://www.tatasteelconstruction.com/en/reference/teaching-resources/architectural-teaching-resource/design/choice-of-structural-systems/introduction Timber Structures. (2009). Glued Lminated Construction. Retrieved 11 1, 2014, from timberstructures.net: http://www.timberstructures.net/glue-laminated-construction.html Read More