Characteristics and Properties of Construction Materials - Assignment Example

CONSTRUCTION MATERIALS Name Institution Instructor Date Question 1: Introduction Modern construction of structures widely involves construction of frames which are either formed from concrete, timber, steel or even a combination of two or all the three materials of construction. Each one of the construction materials has got a distinct group of merits and demerits in their usage and the material choice is largely dependent on the nature of building or construction project being undertaken (Shi and Mo, 2008). Characteristics and properties With regard to properties and characteristics concrete frames, it is possible and much easier to make then into a various shapes and forms through creation of appropriate formwork. This permits the formation of surfaces that are intricately textured as well as the formation of smooth curves. On the contrary, this is more difficult and tedious with the use of timber in the construction of frames and other structures. This only leaves timber for use in most construction applications that requires straight line framing (International federation for structural concrete, 2002). Advantages and disadvantages Most of domestic homes currently are either constructed using timber frames or concrete frames. Both of these construction materials have got their pros and cons. Timber frames The advantages of the pros f or use of timber frames in building and construction of structures include the fact that structures that are prefabricated can be erected on a construction site within a very short time and a slightly lower cost. There is also no loss of much time in the process of construction since their use in construction is not dependent on weather. The use of timber frames in construction makes it possible to use stud wall panels in running services. Another advantage that is associated with the use of timber framed construction is that more accurate edges and corners can easily be achieved as a result of factory built aspect. There are also disadvantages and challenges facing the use of timber as a construction material in constructing frames and other structures. These include the fact that they are poor in terms of strength and durability, the structure have a higher likelihood of being either weakened or destroyed in harsh environmental conditions (Dhir, Newlands and Paine, 2002). Concrete frames The use of concrete frames and concrete in general as a construction materials advantageous with regard to the fact that architects and other building and construction experts are more familiar with the building process and as well as several designs. It is also much easier to make alterations if the foundations are not accurately laid. Concerning the disadvantages in the general use of concrete as material in construction of frames and other structures, the achievement of thermal insulation within a proper level is much difficult. The concrete framed structures are also more vulnerable to large shrinkage and settlement cracks. Construction of concrete framed structures is long tedious and consumes a lot of resources due to the fact that is highly dependent on weather conditions and that it is very slow in drying (Schittich, 2008). Cost The use of timber as a material for construction of frames is cheap as compared to the use of concreted and it does not require a lot of expertise in order to effectively work with them. This makes timber frames to be widely used in a wide range of applications. The use of concrete frames in construction on the other hand is more expensive and demands appropriate form working expertise and skills which may need the hiring of services of a skilled workers. There also exists several cost difference when it comes to construction of either timber or concrete frames structures or buildings. However, considerable savings can be made in costs in the longer term when it comes to the use of timber-framed constructions home due efficiency with regard to energy consumption. Timber frame structures and buildings are subjected to sealing so that the maintain ace of their design does not incur a lot of maintenance cost (Farrelly, 2009). Durability Reinforced concrete frames in the building and construction is widely used due to its stability as a construction material. Structures including frames that are reinforced using concrete as a construction material are more durable and are capable of resisting compression, tension as well as shear forces. Appropriately constructed concrete buildings and buildings are capable of lasting for much extended periods of time. By contrast, wood-framed structures are less durable and can easily be destroyed or weakened by decays or even earthquakes. They are also very flexible and will definitely experience failure when subjected to compression, tension as well as shear forces. Wood-framed buildings and structures are also more vulnerable to damage by water as well as infestations by molds and wood-boring insects. Concrete framed building and structure are comparatively impermeable to water as well as boring by insects and are capable of sustaining damage swelling and contracting due to changes in temperature and moisture (Porteous and Kermani, 2013). Climatic resistance The higher density and mass of concrete-famed building and structures makes it to serve appropriately when it comes to insulation. A building or structure with concrete frame construction has the capability of retaining heat as well as cold in comparison to buildings and structure with wood-framed construction. A lot of structural timber used in framed construction in most parts of the world comes from forests that are managed and is climatically sustainable and renewable. The use of timber a construction material in its plantation is also beneficial to the environment. The harvesting of timber, its production as well as transportation are processes that emit less carbon dioxide in comparison to other construction materials like steel and concrete. The climatic benefits of timber frame construction are subjected to a reduction when the importation of timber is made from external sources and those that require a significant amount of fuel consumption in its transportation (Adegoke, 2012). Ease of assembly and adaptation A concrete framed structure with regard to ease of assembly and adaptation is constructed in a quite different manner from that of timber.  Builders and experts deliver their construction services at the site of construction, in the presence of various weather conditions as they build the structure brick by brick, while they are required to bring the tasks to completion before the next stages are started. All walls that are load bearing are constructed using concrete blocks, partitions and other internally located walls are constructed from stud frames of timber. Precast concrete frames can be erected with the use of spatial beam column or linear elements. Concrete beam-column as well as sub-assemblages are advantageous in that the existence of connecting faces in the middle of the sub-assemblages are able to be positioned away from regions of critical frame; however, linear components are more preferred due to the fact that there are difficulties that are related to handling, formation and the erection of spatial components (Dhir, Newlands and Paine, 2002). The use of linear frame components basically means the positioning connecting faces at the junctions of beam-columns. The concrete frames can be placed on corbels within the columns, in order to make the process of construction easier and to assist in the transferring that takes place from the frame to the column. The joints of beam-column that are obtained in this manner are subjected to hinges. However, rigid concrete frames are connections that are used in some situations, when the stability and adaptability of longitudinal reinforcement has got to be achieved. By contrast timber framed structures are delivered at the site of construction in in panels that are fixed and require the use of cranes in order to lifted and positioned into place. The availability of timber frame that is constructed off site, greatly leads to a reduction in the vulnerability of schedules of work resulting from any exposure to adverse weather (Adegoke, 2012).  References ADEGOKE, B. (2012). Assessment of criteria for selection of timber as building material for building construction projects within Lagos Metropolis. München, GRIN Verlag GmbH. AMERICAN INSTITUTE OF TIMBER CONSTRUCTION. (2012). Timber construction manual. Hoboken, Wiley. DHIR, R. K., NEWLANDS, M. D., & PAINE, K. A. (2002). Composite materials in concrete construction: proceedings of the international seminar held at the University of Dundee, Scotland, UK on 5 - 6 September 2002 ; [during the Congress Challenges of Concrete Construction]. London [u.a.], Telford. FARRELLY, L. (2009). Construction and materiality. Lausanne, AVA Academia. INTERNATIONAL FEDERATION FOR STRUCTURAL CONCRETE. (2002). Precast concrete in mixed construction: state-of-art report. Lausanne, fib. PORTEOUS, J., & KERMANI, A. (2013). Structural timber design to Eurocode 5. SCHITTICH, C. (2008). Interior surfaces and materials: aesthetics, technology, implementation. SHI, C., & MO, Y. L. (2008). High-performance construction materials science and applications. Singapore, World Scientific. Question 2: a) Percentage moisture content of the timber Timber % moisture content = (new mass – original mass) / original mass x 100 = (3.87 – 3.27) Kg. / 3.27 Kg. x 100 = 18.35 % b) Hygroscopic material A hygroscopic material refers to a material that is involved in the attraction of water moisture from the atmosphere when not guarded from the atmosphere. These materials can be protected from the atmosphere through storage under dry gas or under vacuum. Certain materials of this nature absorb a lot of water to an extent of formation of solution and are described as deliquescent. c) Why timber for internal use requires specific moisture This is because the moisture content of a timber affects its strength and hence its area of application or use. The strength of a timber is lowered by reduced moisture content and raised by increase in moisture content. The width as well as thickness is also influenced the level of moisture content. d) Visual and olfactory signs of dry rot and the sequence of action taken to eradicate their outbreak The visual and olfactory signs of dry rot in timber include the presence of rust like decays on the timber sections, shrinking, darkening, cracking, presence of destructive fungus on timber surface and also the detection of rots or decaying matter in concealed areas of the timber or timber structures. The outbreak of dry rot in timber could be eradicated through sequential actions as follows; Removal of timbers that are affected followed by replacement of those that is pre-treated. The remaining timber is then subjected to treatment through an effective use of fungicide. Where other materials are also contaminated, they should be isolated and subjected to sterilization. Question 3: a) Table of percentage on and percentage passing each sieve of sample 2 Sieve size (mm) Mass (g) % on sieve % passing 125 0 0 100 75 0 0 100 63 88 2 98 37.5 55 10 90 20 87 20 80 10 98 33 67 6.3 95 38 62 3.35 102 42 58 2 129 44 56 1.18 89 48 52 0.6 85 53 47 0.3 90 57 43 0.212 92 64 36 0.15 84 68 32 0.063 90 72 28 b) Graph of distribution of particle size c) The distribution of particle size for this particular sample aggregate is not as widely distributed as those of the sample one aggregate and therefore the may be applicable for use in few construction activities. The particle size distribution of sample one aggregate on the other hand is widely distributed and therefore widely applicable in construction. Read More