Overview of Construction Materials - Coursework Example

Construction materials: An overview: Construction industry is one of the richest industries that have experienced a boom in the past few decades, although the scope of construction has always been large. Innovative designs and rich architecture employed in the construction of buildings has changed the look of the world over the years. These fancy buildings speak of the advancement made in the fields of Science and Technology. The Construction industry is also very important for the economic health of a country because various other industries depend completely upon the Construction industry for their existence and progress. Few such industries are the Steel industry, the Concrete industry, the Timber industry and the Masonary. Beautiful combinations of these materials are designed to erect adorable structures. And the approach is not a new one, various buildings in which these materials have been used purposefully have been constructed in the past in general, and in the present age in particular. These materials not only add to the aesthetics of the buildings, but also serve various purposes, unable to achieve for the builders without using them. In this paper, various disadvantages and advantages of each of the above mentioned materials and restrictions in their use in construction are analyzed: Steel: Advantages: Steel is known for its high tensile strength. The strength of steel is quite large as compared to its weight that makes its strength-to-weight ratio the highest among all other construction materials. One of the most appreciable characteristic features of steel is that it is uniform in nature. This uniformity is ensured through a well shaped procedure of refining of the raw steel, and every bit of the final product exhibits same characteristics and strength. Its finishing is smooth, fine and accurate. Often, other chemicals are mixed with to produce Galvanized steel that does not even need to be painted to escape corrosion and can be used as such in grills, doors, containers and various other items. The most appreciated characteristic of steel is that is a fire-resistant material, and contributes much in the prolonged resistance of the structure against demolition when it catches fire. Besides, steel recovered from a demolished building can be recycled and reused for it does not loose its strength and properties over time. Steel does not need to be protected against termite or other insects. Steel does not exhibit any cracking or swelling. Disadvantages: The biggest disadvantage of steel is that it is corrosive in nature and can not be exposed to open air unless covered by a layer of paint. Due to its rich and complex manufacturing and processing, the steel available in the market is very high in cost. Although steel members do not catch fire, yet they collapse because of their high thermal conductivity. This particular characteristic feature of steel requires the provision of additional insulating materials in order to regulate the building temperature. Normally, projects experience a shortage of labor skilled in handling steel and certain equipment necessary for steel construction. Arrangement of these causes the owners to incur additional expenses that they could have escaped had they chosen to use some other material for construction. Limitations: The very high thermal conductance of steel requires heavy cooling procedures for the buildings in warm weather. “Building with steel might not be as cost-effective when you take into account the need for exterior insulation.” (Malin cited in Hiltz, 1999). Also, steel should not be exposed to open atmosphere unless protected with a layer of paint or unless the steel is galvanized in order to prevent the steel from catching corrosion. Steel is not quite suitable as the main structural material in areas near sea or which are high in atmospheric moisture. Masonary: Masonary construction makes use of domestically available materials like bricks and blocks that are bonded with one another with the mortar. Individual essential components like bricks and blocks are also referred to as masonary. Advantages: The materials are cost effective, domestically produced and easily available. The process of making bricks or blocks is also very simple and cheap. This is what makes their availability easy. These units are produced in different strengths as per the need in different parts of the structure. Very high strengths can also be achieved if needed. Bricks extracted from a demolished structure can be reused in some new masonary construction. When used in Reinforced Concrete Structures (RCC), masonary can be used to make cheap and sound partition walls. Disadvantages: Very low strength of Masonry as compared to Concrete discourages its use in the construction of load bearing structures. The finishing of masonary is rough, and masonary walls need to be plastered and painted in order to achieve a finished look. Masonary construction consumes a lot of time and is slow. Masonary construction requires a lot of labor and needs to be watered regularly till several days after erection. Masonary is only capable of taking compression and cannot offer to take tension. Limitations: Since masonary is capable of taking only compression and not tension, this limits its use in construction of compression members and it not be used to construct tensile members in a structure. Masonary construction is not a good option to be chosen in fast track projects. Use of masonary is justified in horizontal construction and can not be made in towers. Timber: Advantages: Timber is one of those materials that are naturally equipped with a very rich and beautiful look, and texture. One of the most appreciated characteristic features of wood is that it is a good insulating material. It can be cut in any size and shape, which permits its usability in members of all types, size and shape. It is very light in weight and adds a lot to the aesthetics of the building. The process of producing / shaping raw timber is also very simple and timber is readily available in almost every place in every season. Small huts may be made up of timber in earthquake prone areas for safety. It is frequently used in construction of portable temporary structures. Disadvantages: Timber is not a load taking material. It needs to be protected against termite. Use of timber calls for anti-termite treatment of the subsoil and foundations of the building. It needs to be protected from water, otherwise it may swell if it comes in contact with water. Timber can not be manufactured and is drawn from natural forests. Timber walls are very light in weight and can not bear loads. Accordingly, it can not be used as a “structural” material. Because of the presence of knots in timber, its strength is not uniform all along the length of a bar and accordingly, a considerable percentage of the whole lot of timber goes wasted. Limitations: Due to its low strength and light weight, timber is not eligible as a load bearing material in the construction of multi-storey buildings. Also, it can not be exposed to open atmosphere unless covered by a layer of paint or polish in order to prevent its surface from coming in contact with water. Concrete: Advantages: Concrete is known as the best compression taking material. The best feature of concrete is that its characteristics can be enhanced as per the demand of the situation with the use of admixtures. It is the most suitable material for use in multi-storey structures and offers good protection against the extremities of weather. Color pigments can be used in concrete to generate a fine and smooth, colored and finished surface. Concrete does not need to be plastered provided that the formwork is well-shaped, fine and smooth. With the use of Tunnel-formwork, whole storey can be cast at a time. Disadvantages: Concrete is weak in tension. It is very costly. With an initial setting time of concrete as low as 30 minutes, it can sometimes make the contractors incur heavy financial losses if they do not manage to make the formwork ready within 30 minutes of arrival of concrete on the site from the batching plant. Concrete needs to be cured for a considerable length of time after its pouring, therefore needs the contractor to spend a lot on purchasing a constant water supply in order for concrete to gain its maximum strength. At times, the complex design of steel reinforcement and formwork require a very high water/cement ratio in the concrete in order for it to reach all areas hidden inside the formwork which is not possible for a dense concrete with a low water/cement ratio. But this is achieved on the cost of the strength of concrete which is inversely proportional to the water/cement ratio kept by the manufacturers. Limitations: Due to its very low tensile strength, the use of concrete is limited to structures meant to take only compression. But it is unnatural for a structure to be exposed to only compressive stresses, because various factors like earth pressure, wind and other forces induce the development of tensile stresses in the structure that is likely to develop cracks if concrete is not reinforced with Steel. References: Hiltz, E., 1999. “The Strength of Steel - use of recycled steel in new home construction - Brief Article”. Available at: http://findarticles.com/p/articles/mi_m1594/is_2_10/ai_54233055/. [Accessed 4 May 2010]. Read More