Materials and Manufacturing for Civil Engineering Level 2 - Essay Example

Materials and manufacturing for civil engineering level 2 Steel as a Construction Component Introduction The utilisation of steel as a construction component in civil engineering is not a new application. For around the last one fifth of a century, steel use and demand has risen to record around 14-18% usage in varying civil engineering applications (Flaga, 2000).Mostly, steel has been used in the growth of infrastructure in developed and developing countries around the world that are adopting its use. For example, in the United Kingdom (UK), a famous utilisation of steel in civil engineering was the construction of the roof domes that make up the river Thames barricades. According to BBC(2014 )“There are many different types of steel, depending on the other elements mixed with the iron”. On consideration of various features that define steel, industry players have utilised it in various construction projects in civil engineering in various levels, large and small. It is made through various techniques from pig iron. However, the goal of each technique is to obtain a fine granulated structure that has carbon as a chemical with the iron in it. ( Chandigarh,2004) .The use of steel has evolved to its usage as the main structural material in the construction industry. As a result, more and more civil engineers are receptive to its use (Flaga 2000). This paper seeks to justify the use of steel in the construction industry by evaluating various parameters associated with it and the contemplation of the nature of the applied stress during its use. Properties of Steel Steel is an alloy of carbon, minute quantities of differing elements as impurities, and iron. In her article LaRoche (2015) states that “Steel has many properties that make it a useful and essential building material”. Its strength and durability make it a great choice for structures exposed to high amounts of stress, such as weather, heat, large amounts of applied force and constant usage”. The maximum amount of carbon in steel is capped at 1.5%, beyond which carbon and iron cannot combine. It is at the 1.5% amount that all of the carbon used in manufacturing steel completely combines with iron (Punmia, et al., 2003). There are various kinds of steel and some of them can be explained as carbon steel, tools steel and alloy steel. Carbon steel is one that has carbon as its main component with no other element as an alloy. The amount of carbon in plain carbon steel ranges from 0.01% to 1.5%. Of importance is the hardness and strength that steel gains from carbon. However, high carbon content leads to a reduction in the malleability and ductility of steel (Wadhawa & Dhaliwal, 2008).Tool steels is a king of a steel which contains tungsten, cobalt, vanadium and molybdenum in different quantities .This is done mainly to increase heat resistance and durability and this in turn makes the tool steel more ideal for drilling and cutting purpose. Another kind of steel which is alloy steel consist of alloying elements like silicon, manganese and copper in varying proportion and this in turn increases the durability, strength and weld ability of the metal. Here, it could be understood that these types of steels make potential building components and this can be elaborated further in below section. A building component – Steel Column Steel column is one of the building component which uses steel primarily as its material .Steel Column is an important building component when it comes to construction as they are widely used in both single and multi storey buildings. According to (Tata Steel) “Columns and struts carry load primarily in compression along their length, and are found in most building structures”. Basically, columns are an integral part of modern building structures and form the basic part of modern framed buildings. In some cases, steel columns are used to carry lateral wind load and bending .Mainly, in case of multi – storey buildings the columns are restrained at every floor level and the length of the columns depends largely on the storey height. The steel column is an efficient building component as it is used in many building structures and in case of single storey building these columns are given special consideration as it can vary according to the construction details. The efficiency of the columns can be further determined from the fact that they are often subjected to some bending in addition to compression. The strength of the steel column is enormous as it can hold many kinds of structures like bridges, buildings and towers. Steel columns are widely known for their high strength, uniformity and elasticity. As per (Assakaf) “A very desirable of property of steel in which steel can withstand extensive deformation without failure under high tensile stresses, i.e., it gives warning before failure takes place”. So when compared with concrete columns and timber columns the steel column fare well and it can be proved in the following section. Comparing steel column with concrete column Apart from steel columns, the concrete columns are also widely used in building construction. Both the columns have its good and bad side and a mild comparison can give us an idea about the efficiency of steel column against concrete column. In their journal (strunet ) has explained that “Concrete column is one of the most interesting members in concrete structural design application”. Basically, when we look at the strength to weight ration, steel has high strength to weight ration when compared to concrete columns. The strength to weight ratio of steel is 32.31 when compared to concrete which has 2.23 ratios. Also when it comes to stress the steel column is different from that of concrete columns. For example, the capacity of the W10×15 section = 45.4 kips, based on a slenderness ratio, KL/r = 118.5 and an allowable stress of 10.29 ksi. Now, we need to look into the carbon emission of steel column and concrete column . The CO2 emission calculation for steel column and concrete column is same but the result varies according to the thickness of material or density. ƒ = ƒ1 + Am L E Here, the ƒ1 is the co2 emission of steel column and A and L are the cross sectional area and length and E is the co2 emission per unit volume. Steel column thickness and co2 emission 0 < thickness ≤ 25 0.86 USD/kg 6.51 kg-CO2/kg 25 < thickness ≤ 38 0.86 USD/kg 6.57 kg-CO2/kg In the same way, the co2 emission of concrete column can be calculated this way Concrete column carbon emission 21 MPa 48.23 USD/m3 472.61 kg-CO2/m3 So, here we can see that steel column is giving out less emission than concrete column. If we look at the stress of concrete column it has a reduced value in comparison to steel column. So, the concrete column has less reputation in comparison to steel as a building component. According to Weiss( 2014)“Concrete belongs to a class of materials that can be called ‘Strain – softening’, indicating a reduction in stress beyond the peak value with an increase in the deformation (as against the strain hardening behaviour commonly exhibited by metals like steel). So we can see here that, the concrete column is less valuable in comparison to steel column. According to Asdip( 2015) “Failure in concrete columns could occur as a result of material failure or by loss of lateral structural stability. However, the case is different when it comes to appearance and aesthetics of concrete column. The concrete column has much better appearance when compared to steel columns otherwise steel column is apt in construction Comparing steel column with timber column Another building component which is used in construction is the timber column. Timber column is basically made from timber that means wood. In comparison to steel column, timber columns are more sustainable and this makes it an attraction in the construction field. Timber is the oldest construction material. According to Abeysuriya( 2015) “Timber taken from well managed forests, is the most sustainable construction material. It has minimum or no effect on the environment when disposed of as construction waste”. But in comparison to steel column, the timber column is far more expensive and their strength to weight ratio is different when compared to steel column. Here the carbon emission of timber column is calculated and then compared with that of steel column. 1KW/h = 100g CO2 Production of a 5m timber column = 70 kg of CO2 So when comparing to steel column the timber column is more sustainable and efficient when it is the question of carbon emission.According to Titan Timbers (2012 ) “Timbers columns provide the best strength-to-weight ratio for the building trade. Tool and machine friendly, the columns cut, screw, nail and notch quicker and easier, to save you time and money”. So here we can find that timber columns have some advantages in comparison to steel columns. Now, let us see the strength of timber columns in comparison to steel column .One kind of timber column is glulam which is more often used in construction. According to Buckland Timber (2013 )“Timber has a good strength to weight ratio in comparison with steel and concrete. If you consider equivalent beam sizes for the same load bearing capacity in glulam and steel, glulam has approximately 1.5 – 2 times the strength to weight ratio of steel. It is evident that steel provides a great room for off-site preparation; hence, errors that could arise during manual work are significantly decreased with the overall cost of construction been reduced considerably (Boothroyd, et al., 2010) Conclusion . In this paper, the comparison has been made of steel column with concrete and timber column. In many ways, steel column seems to be more apt for construction than concrete or timber column. The reason here is that steel column is more viable and has better strength to density ration than concrete or timber column. According to Thackray and Burden (2012), the strength-to-weight ratio of steel is good. As noted, the self-weight of structures made up of steel is not more than 15% of the total weight, which denotes a good strength-to-weight ratio. The problem with concrete column and timber column is that it cannot withstand pressure like steel columns. Steel that has the utmost high-temperature strength, which is 18/8, shows the greatest dimensional stability (Totten & Howes, 1997). Steel when compared to concrete is more durable and ductible because concrete column is not efficient enough to handle the pressure in case of multi – storey buildings or huge constructions. But when it comes to timber , the issue is that it s quite expensive and it is less durable than steel column.Finally, it could be understood that steel column is the ideal option in comparison to concrete and timber column when it comes to building materials. References Assakaf, R., 2002. INTRODUCTION TO STRUCTURAL STEEL DESIGN. 3rd ed. Maryland: Prentice Hall. Abeysuriya. 2015. EFFECTIVE USE OF STRUCTURAL TIMBER FOR SUSTAINABLE CONSTRUCTION. [ONLINE] Available at:http://www.academia.edu/7067865/EFFECTI VE_USE_OF_STRU CTURAL_TIMBER_FOR_SUSTAINABLE_CONSTRUCTION. [Accessed 05 March 15] ASDIP. 2015. ASDIP Concrete – Concrete Columns Design. [ONLINE] Available at: http://www.asdipsoft.com/products/concrete/columns/. [Accessed 05 March 15 Buckland Timber. 2013. Glulam. [ONLINE] Available at: http://www.bucklandtimber.co.u k/about-our-glulam/benefits-of-glulam/. [Accessed 06 March 15]. BBC. 2014. Metals. [ONLINE] Available at: http://www.bbc.co.uk/schools/gcsebite size/science/a qa_pre_2011/rocks/metalsrev3.shtml. [Accessed 06 March 15]. Boothroyd, G., Dewhurst, P. & Knight, W. A., 2010. Product Design for Manufacture and Assembly. 3 ed. New York: CRC Press. Chandigarh, T., 2001. Civil Engineering Materials. 13 ed. New Delhi: Tata McGraw-Hill Education. Carolyn LaRoche. 2015. Properties & Uses of Steel . [ONLINE] Available at: http://www. ehow.com/list_7271721_properties-uses-steel.html. [Accessed 06 March 15]. Flaga, K., 2000. Advances in materials applied in civil engineering. Journal of Materilas Processing Technology, 106(2000), pp. 173-183. Strunet Concrete Design Aids, 2010. Introduction to Concrete Column Design Flow Charts. Strunet, 1/1, 1-10. Punmia, B. C., Jain, A. K. & Jain, A. K., 2003. Basic Civil Engineering. New Delhi: Firewall Media. Totten, G. E. & Howes, M. A. H. eds., 1997. Steel Heat Treatment Handbook. New York: CRC Press. Thackray, R. & Burden, M., 2012. Applied metallurgy of steel. In: B. Davison & G. W. Owens, eds. Steel Designers Manual. Londona: John Wiley & Sons, pp. 305-330. Titan Timbers. 2012. Titan Timbers Glue Laminated Columns.. [ONLINE] Available at: http://www.timber-technologies.com/titan.phtml. [Accessed 06 March 15]. Tata Steel. 2014. http://www.tatasteelconstruction.com. [ONLINE] Available at: http://www .tatasteelconstruction.com/en/reference/teaching-resources/architectural-teaching-resource/elements/design-of-columns-and-struts/introduction. [Accessed 05 March 15]. Weiss,J. 2015. Stress-Strain Behaviour of Concrete. [ONLINE] Available at: http://www. theconcreteportal.com/cons_rel.html. [Accessed 04 March 15]. Read More