Why are walls important?

Why are walls important? Why are walls important? Walls are very important parts of buildings, they have several useful functions: * Protect us from dangerous animals and people * Provide shelter from elements such as wind and rain * Makes a ‘secure home * Bears the loads of the roofs, floors and furniture Block work Standard blocks are 6 times larger than standard bricks, this means that bricklayers can build the wall more quickly, therefore taking less time and reducing labouring costs. For the walls, the external walls will be cavity walls made from aerated concrete blocks and the internal walls will be made from dense concrete blocks. The reasons for these choices will be explained further on. What are and Aerated Concrete blocks and why I have chosen Duncan Marshall (2008) says that; Aerated blocks consist of water, cement, pulverised fuel ash, sand and lime. Aerated concrete blocks are very versatile as they can be used in many different parts of the building, such as party and solid walls, cavity walls (internal and external leaves) and foundations. We will be using Celcon aerated concrete blocks, which are BBA certified (British Board of Agrà ©ment, which is the UKs major authority offering approval of construction products). Sizes (in mm): 215 125 440 Reasons for using Aerated blocks for the inner and outer leaf: * Good thermal insulation (Thermal conductivity is 0.15W/mK, Thermal conductivity is the ability of a material to transmit heat, the lower the value the better) * Easy to handle for labourers/bricklayers, as theyre relatively lightweight and can be cut and chased * Closed cell structure means they have good water penetration resistance * Good fire protection Class O surface spread of flame (the best rating) * Non combustible * Relatively strong (Strength 3.6 N/mm ²) What are Dense Concrete blocks and Why I have chosen them? Dense concrete blocks consist of cement, aggregate (fine and coarse). We will be using Celcon Hi (7) Strength blocks. Sizes (in mm): 215 150 440 Reasons for using dense concrete blocks for the internal walls (party/solid walls): * Very strong (7.3N/ mm ²) * They provide a good surface for most renders and plasters * Good sound protection This is an illustration of a building regulation (part A) for the compressive strength needed of walls. For the external walls it will be a cavity wall comprising of aerated concrete blocks (7.2N/mm2), and the inner walls will be a solid wall of dense concrete blocks (7.3N/mm2). Height of wall Length Minimum thickness Not exceeding 3.5m Up to 12m 190mm for whole height Exceeding 3.5m but not 9m Not exceeding 9m 190mm for whole height 9m 12m 290mm from base for 1 storey and 190mm for remaining height Exceeding 9m but not 12m Not exceeding 9m 290mm from base for height of 1 storey and 190mm for rest of height Exceeding 9m but not 12m 290mm from base for the height of 2 storeys and 190mm for rest of height This is a table from the building regulations (Part A) about the thickness of walls. For our design, the internal and external walls both exceed 290mm, therefore the walls will have the correct thickness. Mortar Mortar is needed to bond the blocks together to provide stability for the wall, therefore building. It also seals gaps between the blocks to prevent water getting through the gaps when it rains. Blocks (aerated and dense) Duncan Marshall (2008) recommends our buildings will have a mortar ratio of 1:1:6 (cement: lime: sand). The reason for having a low amount of cement (cement provides the strength) compared to the sand (sand gives volume), is that making the mortar not that strong is so that it doesnt limit movement and will cause cracks in the joints rather than the concrete blocks. This mixture is recommended by a professional concrete company, therefore it wont be too weak, as then the mortar will fail. Jointing/pointing bucket_handle.gifAll of the buildings will have the bucket handle design. This is because Duncan Marshall (2008) says it helps seal the joint, also it compresses the mortar slightly and the shape improves resistance to water penetration. Walls Quoins Out of these three different types of bonding block work we will use 5 (reveal quoin), because its the most simple bond, therefore easier for bricklayers to build the wall, and reducing the likelihood of errors occurring. Also 3 bonding will be used if needed to keep the whole wall to the correct dimension. Cavity Walls For all our cavity walls in our buildings, they will be partial fill cavity walls. Kingspan Insulation says; one of its main advantages is that it prevents rain getting to the inner leaf, which would cause dampness in the walls, therefore weakening the walls. One disadvantage with partial fill cavity walls happens in the physical construction of the wall takes place, if the walls arent sealed completely, airflow in the wall leads to an enormous amount of heat loss within the wall (shown by red areas in 2). This can be caused by dirty ties and mortar snots, which are pieces of mortar which have dropped into the cavity, and cause moisture. 125 75 20 125 20 Block Cavity Insulation Plasterboard 365mm F . Cavity Walls Wall ties Duncan Marshall (2008) says; as we are having a partial fill cavity we have to use this special tie with plastic retainer. In the 2004 Regulations (Approved Document A) there is a requirement to use stainless steel ties. Building regulations says the tie should be bedded at least 50mm in each leaf. In terms of the tie angle, it should be slightly sloped toward the outside leaf; otherwise the other leaf will get damp. Cavity Walls Movement joints The materials that make up a wall will expand and contract because of reasons such as temperature and moisture content. Because concrete blocks are made of cement, they will shrink slightly. Therefore, the big sections of wall need to be shortened to accommodate for the movement, if movement joints are placed correctly, this will prevent the wall from cracking. Duncan Marshall (2008) says that the movement joints of internal concrete block walls should have movement joints approx every 6 metres, but the 1st joint should only be 3 metres away from a corner or bend in the wall. We will incorporate this into our designs. Cavity Walls- Jambs The blue line is the window Damp proof course prevents water penetration from the jamb of the window frame Cavity Walls Lintels Duncan Marshall (2008) say that the lintels carry the distributed load of brickwork across the top of the window frame. Lintels can be up to lengths of 4500mm and when constructed should have at least 150mm bearing on the wall either side. Lintel with insulation to prevent cold bridging, cold bridging happens when heat is lost from the inside of the building to the outside because the material (this case the lintel) is the ‘bridge for the heat loss. When the insulation is there, it has a higher thermal conductivity than the lintel (galvanised steel), so the heat ‘bridges to the insulation and not outside the building. 10 This is very important concept of insulation, that also applies to cavity and solid walls where insulation is used. Insulation External Walls Insulation boards are used to keep the heat within a room/building so that the living/working conditions are favourable. We will have WT20 insulation boards (size is 1200x600x20mm) from warmtiles.co.uk Board Sizes Thermal Conductivity (W/mK) Resistance (k-value) U-value (W/m ²K) Weight (kgs) 1200 x 600 x 20 mm 0.029 0.69 1.45 0.45 The U value is the amount of heat which will flow through 1 square metre of a wall for every degree in temperature difference between the inside and outside. Resistance is the resistance to heat flow of a material of a given thickness. Now I can calculate the U-value for the walls. U value for cavity walls (Thickness/Thermal Conductivity = Resistance) This transitions into weep holes; weep holes allow the water to exit the cavity. As we are only using blocks, we will use plastic weep holes that are placed every 450 mm. Weep holes, damp proof courses and the bucket handle mortar are excellent parts of the wall that allow it to prevent water penetration. Cavity Walls-Sills Cavity Walls joining cavity walls to internal walls This is how we will join the inner leaf to the internal walls, also where two internal walls (could be party walls) join, it will be toothed in. Walls Door and Window frames (Openings) The building regulation below specifies the sum of openings (w1+w2) shouldnt be more than 2/3 ‘L. Opening heights should be less than 2.1m, and the width less than 3m. This ensures the wall is not weakened significantly under compression by openings. We used this formula for a standard room (not disabled). Length of whole wall Door sizes Thickness= 40mm 2040 mm 826mm Windows A very common part of walls, and obligatory for accommodation buildings are windows. Window sizes (British Standard: 2003) 1050 mm 1800 mm *Purple segments are windows that open (white arrows indicate what direction they open), orange segments are fixed. This type of window is called ‘Left-hand multi light. Sound Control One of the functions of the walls is to control the airborne sounds, such as aeroplanes and cars travelling outside of the building. The internal walls will be made out of dense concrete blocks, as this provides good sound protection. Celcon aerated blocks also have just as good of a level of sound protection. Osbourn and Greeno (2007), say the Sound reduction index (SRI) is a way of measuring the effectiveness of construction insulating airborne sound. We will have a block cavity wall which is plastered, this has a SRI number of 49, and 150 mm dense concrete walls which have a SRI number of about 46. These are relatively acceptable SRI values to be used in construction. Finishes There are different finishes you can have for aerated concrete blocks; plastered, rendered and painted. For the outside of the external walls we will render the walls (10mm wide). For internal walls (dense concrete blocks) we will have plaster boards (20mm wide). Cement Rendering After the mortar and blocks are bonded, render will be applied. For our design we are using aerated concrete blocks for the external walls, therefore we should not use strong renders (Duncan Marshall, 2008), because when the dense mix shrinks, it will go past the limit of stress that the blocks can handle, therefore cracking will occur. Our building will have a very similar aesthetic appearance to this building (right), except for the colour. References David Littlefield, et al., 2008, Metric handbook, 3rd Edition, Duncan Marshall ,2008, Construction Website 0809 (unframed construction) http://learn.lboro.ac.uk/file.php/1183/UWE08/index.htm Dereck Osbourn and Roger Greeno, Mitchells Introduction to Building 4th Edition Julian McKenzie (Lectures) Sizes of concrete blocks http://www.sigexpress.co.uk/Aerated-Concrete-Blocks/Celcon-100mm-Standard-Block.htm Partial Fill Cavity Walls http://www.insulateonline.com/index1.htm?walls2.htm~main Insulation Boards http://www.warmtiles.co.uk/category.php?id_category=17 Analytical Essay: The Teaching Of Speaking Analytical Essay: The Teaching Of Speaking The theme of the research paper is The Teaching of Speaking. For the teacher it is very essential to know how to teach speaking foreign language correctly and to be able to do that. That is why there are several methods and manners how to give the knowledge in an easier manner to the students. The aim: To investigate what methods are used to teach speaking are used mostly and find out as many as possible teaching speaking methods. The enabling objectives: to find out and study theory on the teaching of speaking(mention the theme) to collect and summarize the gained data to draw conclusions The research question: Which methods are used to improve teaching the teaching of speaking? The methods of research: analysis of the theoretical material case study The tools of research and data collection: analysis of the teaching of speaking methods 1.THE TEACHING OF SPEAKING What is speaking? In fact, speaking is an action carrying out the information or expressing feelings and emotions, persons thoughts in spoken language. Speaking is also the process of building and sharing meaning through the use of verbal and non-verbal symbols, in a variety of contexts (Chaney, 1998, p. 13). By the teaching of speaking is meant to produce the English speech sounds and sound patterns, use word and sentence stress, intonation patterns and the rhythm of the language, select appropriate words and sentences according to the proper social setting, audience, situation and subject matter, organize their thoughts in a meaningful and logical sequence and use language as a means of expressing values and judgments (Online 2). 1.1Strategies for Developing Speaking Skills According to the internet source, students often think that the ability to speak a language is the product of language learning, but speaking is also an important part of the language learning process. Effective instructors teach students speaking strategies using minimal responses, recognizing scripts, and using language to talk about language (Online 1). These strategies can help students to enlarge their knowledge of language. If the students are confident in speaking, it would be more easier to receive the other information while learning. 1.1.1Using minimal responses Language learners who are not confident about their ability to participate successfully in oral disscussions often listen in silence while others do the talking. One way to encourage such learners to begin to participate is to help them build up a stock of minimal responses that they can use in different types of exchanges. Such responses can be especially useful for beginners (Online 1). Minimal responses are predictable, often idiomatic phrases that conversation participants use to indicate understanding, agreement, doubt, and other responses to what another speaker is saying. Having a stock of such responses enables a learner to focus on what the other participant is saying, without having to simultaneously plan a response (Online 1). 1.1.2Recognizing scripts Some communication situations are associated with a predictable set of spoken exchanges a script. Greetings, apologies, compliments, invitations, and other functions that are influenced by social and cultural norms often follow patterns or scripts. So do the transactional exchanges involved in activities such as obtaining information and making a purchase. In these scripts, the relationship between a speakers turn and the one that follows it can often be anticipated. Instructors can help students develop speaking ability by making them aware of the scripts for different situations so that they can predict what they will hear and what they will need to say in response. Through interactive activities, instructors can give students practice in managing and varying the language that different scripts contain. 1.1.3Using language to talk about language Language learners are often too embarrassed or shy to say anything when they do not understand another speaker or when they realize that a conversation partner has not understood them. Instructors can help students overcome this reticence by assuring them that misunderstanding and the need for clarification can occur in any type of interaction, whatever the participants language skill levels. Instructors can also give students strategies and phrases to use for clarification and comprehension check. By encouraging students to use clarification phrases in class when misunderstanding occurs, and by responding positively when they do, instructors can create an authentic practice environment within the classroom itself. As they develop control of various clarification strategies, students will gain confidence in their ability to manage the various communication situations that they may encounter outside the classroom. 1.2How to teach speaking According to the given internet sources, now many linguists and teachers consider that students can improve their communication and speaking skills working into groups together with other students and playing real-life situations in the target language. To achieve the goal of speaking well, the students need to improve their language fluency (speaking smoothly), pronunciation (saying words properly) and enunciation (saying words and phrases clearly) (Online 4). Fluency comes from practice. Every English speaking person cannot improve speaking smoothly in some two months, it comes after longer time. T o get to the aim, there should be made speech of long, complicated sentences. For example, to build more fluent speech, a helper could be discussions, presentations, role plays, negations, debates, interviews and meetings. Pronunciation is the ability to say words properly with the correct sounds in the correct places (Online 4). To make words sound correctly, it can take very long time to develop the pronunciation. As suggested in the internet source, the student should focus on working on specific vowels, trouble consonants, and working on understanding movement and location of mouth and tongue when making sounds (Online 4). In phonetics, enunciation is the act of speaking. Good enunciation is the act of speaking clearly and concisely (Online 5). If the enunciation of the speech is pure, others will not be able to understand speakers speech. To avoid misunderstandings in the communication towards others, according to the internet sources, the student should pay attention to trouble word combinations, reductions, sentence and word level stress points and sentence level intonation patterns. 2.WHICH TEACHING METHODS ARE MORE PREFERABLE FOR STUDENTS THEMSELVES If there were a questionnaire, the aim of it would be to clear up which of the teaching methods are more understandable and useful for the students themselves. No one can answer to this question more precise and honestly as the students. CONCLUSIONS The teaching of speaking means that the teacher gives the knowledge to the student how to communicate with others, to produce sounds, words correctly and clearly, to use precisely intonation patterns, to choose appropriate themes which to speak to the proper social setting and audience. There are a lot of teaching methods which can be used in the teaching process, but, in my opinion, more preferable methods are those who are easier and understandable for the students. For instance, to make your speech more fluent and clearer, it can be enough to read articles with complicated vocabulary and sentence structure aloud every day. Rounding up, if the teacher is teaching in a simple manner and understandable for students. THESIS Speaking is an action carrying out the information or expressing feelings and emotions, persons thoughts in spoken language. Many linguists and teachers consider that students can improve their communication and speaking skills working into groups together with other students and playing real-life situations in the target language. To build more fluent speech, a helper could be discussions, presentations, role plays, negations, debates, interviews and meetings. Fluency comes from practice. Every English speaking person cannot improve speaking smoothly in some two months, it comes after longer time. Effective instructors teach students speaking strategies using minimal responses, recognizing scripts, and using language to talk about language.