The Design Process and the Main Principle Requirements of a Project - Assignment Example

Part 1 - Building Process Identify the members of a typical building team and their respective roles. Describe the design process and the main principle requirements of a project. The Building Team Building is essentially a team process in which each member has an important role to play. The following are building team members and their respective functions. Building owner - The client; the person or organisation that finances and commissions the work. They directly or indirectly employ all other personnel, with particular responsibility for appointing the planning supervisor (usually the architect) and nominating the principal contractor. Architect – Engaged by the building owner as agent to design advice and ensure that the project is kept within the cost and complies with the design. Consulting engineers – Engaged to advice and design on a variety of specialist installations, e.g. structural, fire, services and security. They are employed to develop that particular aspect of design within the cost and physical parameters of the architects brief. Principal or main contractor – Employed by the client on the advice of the architect, by nomination or competitive tendering. They are required to administer the construction programme within the architect’s direction Contract’s manager or site agent – On large projects, the main contractor’s representative on site, with overall responsibility for ensuring that work proceeds effectively and efficiently, i.e. in accordance with the design specification and to time. Sometimes known as the general foreman, but this title is more appropriate on small to moderate sized contracts. Surveyor – Employed by the main contractor to check work progress and assist the quantity surveyor in the preparation of interim valuations for stage payments and final accounts. May also be required to measure work done for bonus and subcontractor payments. Estimator – Prepares unit rates for the pricing of tenders, and carries out pre-tender investigations into the cost aspects of the proposed contract Buyer – Orders materials, obtains quotations for the supply of materials and services. Accountant – Prepares and submits accounts to clients and makes payments to suppliers and subcontractors. May also have a costing department that would allocate the labour and material costs to each contract to assist with the preparation of accounts. Administrator – Organises the general clerical duties of the contractor’s office for the preparation of contract documents and payment of salaries, subcontractors’ and suppliers’ invoices, insurances and all necessary correspondence. Assistant contract manager – Often a trainee, in the process of completing professional examinations. Assists with the general responsibility for administering site proceedings. Nominated subcontractor – Engaged by the client or architect for specialist construction or installation work, e.g. lifts and air conditioning Site Investigation - A self-builder has approached you with a view to developing the site shown; he wants a full site investigation report of the site before he is prepared to proceed with the development. Describe the steps that you would take in preparing this report, the factors that you would consider and the materials & equipment you would use in the execution of your work. Type of foundations Foundations are broadly classified as being either shallow or deep foundations. This division is made not only on the relative level of the subsurface horizon or strata selected for bearing, but also on the supporting mechanisms used to achieve that bearing. Pad, ribbon and slab-on-grade are shallow foundations, they are generally used for small buildings, broadly distributed loads, and buildings that are located on soils with strong bearing capacities. Occasionally buoyant foundations may be used to overcome a high water table. Pad foundation: This is isolated columns that do not support large loads on a pad as shown in Fig.1 below. The size of the pad is based on the size of the applied load compared to the bearing capacity of the soil upon which it rests Fig. 1 Pad foundation Source: class notes (foundations) Strip and ribbon foundations Strip foundations are used where the bedrock is very shallow and thus the stem wall can rest directly on the bedrock with a very small narrow strip known as a footer being the interface between the bedrock and stem wall. Fig 2: Strip foundation Source: class notes (foundations Ribbon foundation is required where the bedrock is deep a ribbon or a wide strip footing may be required. The principle applied is that the higher the load applied and the weaker the soil, the wider the ribbon should be. Fig. 3 Ribbon foundation Source: class notes (foundations Deep foundations. Deep foundations are appropriate in a situation where the site for building has soils that expands or compressible. Deep foundations are usually necessary in building of large buildings which have highly concentrated loads. The common deep foundations are the pile and pier foundations. Piles are usually slender and are usually driven in the ground just like the tent pegs. In circumstances where the bed rock is very deed strike friction piles are used are put into use instead of end bearing loads. Fig. 4 Pile foundation Source: class notes (foundations While piles are usually driven into the ground piers are either drilled or excavated. Just like the case of piles the drilled piers can completely pass through the overburden into a socket in the bedrock beneath. In some cases the inherent shin friction on the shaft may be supplemented by the base into a bell shape Fig. 5 Pier foundation Source: class notes (foundations Failure in foundations Pad foundations develop shearing stress in the pad that can result in punching shear. This can be taken care of by making the pad thick to provide enough shear strength. Foundations which are on steep slopes may fail by sliding. Deep foundations will slide along the top of such sloped bedrock if not socketed into the bed rock. A common solution for shallow foundations on steep slopes is to step them in. In general it is best to keep the length of these steps as long as possible, and the height as small as possible. Piles may fail by buckling and this problem can be taken care of by using cluster piles and also through the use of battered piles which are driven at right angles. Ventilation - With regards to the appropriate approved document discuss the purpose of ventilation and the different types of ventilation. Discuss the ventilation requirements for domestic buildings. Discuss the term performance based ventilation. Part 2 - Materials Density 1)Calculate and then place in descending order the density (kg/M3) of the following materials: a)3.6m3 C25 concrete of mass 7920kg, b)3200 x 50 x 75mm Mahogany of mass 7800g, and D= = Density of concrete= 2200 kg/m3 Volume of Mahogany== 0.012 Mass of Mahogany (kg) = =7.8kg Density of Mahogany ==650kg/m3 2)A concrete lintel has the following dimensions 1.800m x 0.150m x 0.100m and a bulk density of 2100kg m3. The lintel contains 2 reinforcing bars of diameter 15mm which run its full length. If the density of the rebar is 7830kg m-3 calculate the mass of the concrete in the lintel. Mass of lintel = D×V=2100 × 1.800m x 0.150m x 0.100m =487.8 Mass of bars M= = 2.7658 Mass of concrete = 487.8-2.7658 = 485.0342kg Natural Stones 3) Which of the three types of rock has the greatest percentage porosity? How does this relate to the grain shape? Sedimentary rocks have the highest porosity. Spheroidal shapes have high porosity. 4) Provide an example of 1 type of stone from the rock classes – metamorphic, igneous and sedimentary and give examples of their use in construction. Examples Cedimentary: limestone. Metamorphic: marble. Igneous :obsidian. Sedimentary used in construction where complex shapes are required Ignatius- used as aggregate and where irregular shapes can be useful like in road and dam construction. Brick and Block 5) Define the term “Initial rate of absorption”. This is the measure of the rate of absorption of moisture when a dry brick comes in contact with water. 6) Define the term “capillary action” and the affect that pore size will have on this. This is the movement of water against the force of gravity in small conduits 7) How does initial rate of absorption affect the bond between bricks and the mortar? A very high initial absorption rate results into a weak bond between the brick and the mortar. This is because there is no enough water left for chemical reaction that will effect the bonding between the brick and the mortar 8) Water absorption is an important factor in the durability of a brick. State two adverse conditions that could arise from excess water in bricks. Excessive water in the brick will make it loose its strength and also can increase the dead load. This combination can make a building to collapse. Metals 9) What affect does the carbon content have on the ductile/ brittleness properties of mild steel? an increase in the amount of carbon makes the steel to be tough and brittle in contrast low carbon steel will tend to be more ductile 10) Describe briefly, the following heat treatment processes: a) Annealing, this is the process where cast iron is softened by to heating to a range of 760ºc to 815ºc for some time then cooling it slowly b) Normalizing involves heating the steel to about 30º c to 40º c above the higher critical point and then cooling in the air with the end results being a finer and more dispersed pearlite c)Quenching. This is done as part of the process of hardening cast iron. The cast iron is first heated to 815c 870c followed by the quenching process then tempering. The quenching process involves the cast iron being dipped in the oil during the cooling process. Water and air can also be used as the quenching media 11) Explain why high-carbon steels would not be suitable for reinforcement for concrete. The essence of reinforcing concrete is to withstand a higher tensile stress. This is because concrete can with stand a very high compressive stress but is very weak when under tension. To improve the capacity of concrete to withstand higher tensile load it need to be reinforced with material which are strong in tension. Therefore high carbon steel is not the best as is equally poor in supporting tensile forces just like concrete. Corrosion 12) Define the term “corrosion”. Corrosion is the disintegration of an engineered material into its constituent atoms due to a chemical reaction with its surrounding OR In the most common use of the word this means the electrochemical oxidation of metals in reaction with an oxidant such as oxygen. 13) Give an example of how each of the metals tested may be used in the construction industry. (a)Zinc used in galvanization (b) Mild steel used in manufacture of bars and plates which are used in construction industries (c) Aluminum, used as reflect surfaces and in buildings it is commonly used in urinals (d)Lead, Used for pipe network in buildings and roof coverings (e)Copper, Used for dump proofing buildings (f)Brass, and us to make pipe linings (g) Stainless steel. 14) How can corrosion of metals used in the construction industry be minimized or avoided? By painting, greasing or storing away from moist environment Cement, concrete and cement replacements 15) Briefly explain what cement replacements are and discuss why they are used in the construction industry. As the name implies, cement replacement materials can be used as a substitute for some of the Portland cement in concrete, partial cement replacement materials is a more accurate name. The materials can give useful modifications to the concrete properties for certain applications and as they are often a waste product from other industries they can also lead to a great reduction in costs. 16) Briefly discuss why heat is produced when hydration occurs and explain why this relationship should change with differing cement / replacement mixes. Heat production results from the different chemical process taking place in the concrete. This includes the heat of the wetting, heat of solution and the initial reactions of the aluminate phases. The amount of heat will change with different cement/replacement mixes. This is because cement is compost of different components which produce different amounts of heat of hydration. Some of the components include gypsum, calcium sulphaluminate,and tricalcium silicates.tricalcium silicate is responsible for production of most of the heat of of hydration and when different cement types with different amount of this compound are used it results in a change in the amount of heat of hydration produced. 17) Does the amount of water used in concrete mixes affect the strength and density of the concrete? If so why? The different components in cement react with water to form the compounds that make the concrete to have strength. If there is no enough water the chemical processes will not be complete and the resulting concrete will be weak. On the other hand when the water reacts with cement components there is formation of compounds that occupy a higher volume. If there is no enough water to complete hydration process the increase in volume will not be complete and there will be unfilled pore in the concrete thus making it to be porous. On the other excessive water will ensure that the hydration process is complete but there will also be remaining extra un-reacted water. When the water dries out there will be unfilled pores which will make the concrete to be weak and porous. The highest density and strength is obtained when we just have enough water to complete the hydration process.The engineer must decide what ratio will give the best result for the given situation. This is not an entirely free choice because the water/cement ratio needs to be about 0.25 to complete the hydration reaction. Typical values of w/c are between 0.35 and 0.40 because they give a good amount of workability without sacrificing a lot of strength. 18) Would you use a concrete of water: cement ratio 0.4 or 0.8 in high sulphate environments? Explain your answer. When sulphates penetrate into concrete they react with it destroying its quality. In a high sulphate environment it is advisable to use water cement ration that will not make the concrete to be porous. Thus a water cement ratio of 0.4 should be chosen over 0.8 Aggregate 19) List any three characteristics of concrete aggregate and discuss their influence on the properties of fresh concrete. They are inert, stiff and have strength, and are not porous 20) Would a well graded aggregate have a low or high porosity? Give reasons for your answer. Well graded aggregate will have low porosity, because of the fact that the grain sizes of the aggregates are such that there will be very small spaces within the aggregate which will be filled easily by the hydration process. 21) What percentage does the fine and coarse aggregate occupy in a concrete mix? Give 3 reasons why aggregates are used in concrete. The aggregate occupy 70 % to 80% of the concrete mix. Aggregates are used to act as filler material, they give concrete the desirable strength and they provide surfaces for reaction of water and cement components. 22) Materials passing a 75μm sieve are defined as what? At what sieve size does an aggregate change from being classed as a fine aggregate to a coarse aggregate? Timber, 23)Draw and label diagrams of the cellular structure of hardwoods and softwoods from the transverse view. From your drawings describe the differences between hardwoods and softwoods at the cellular level. Figure 4: Growth rings in a softwood Softwoods are composed mainly of two types of cell. The most numerous are tracheids which are long and thin, and are aligned with the stem and branch axis. The others are rays that are aligned in a radial pattern. Figure 5: Schematic diagram of the structure of a ring porous hardwood Hardwoods have a more complicated structure and have three main types of cells: vessels, fibres and ray 24) Define the term “coefficient of thermal expansion”. This is the comparison of the linear expansion recorded per unit length when the temperature is raised by 1 degree cent 25) Define the terms “Modulus of Elasticity” and “Modulus of Rupture” . Modulus of elasticity is the ration between the stress in the material and the strain in the material before the material reaches the yield point while Modulus or rapture is the ration between the stress in a material and the strain in the material when it is just about to break. 26) What are the main applications for hardwoods and softwoods in construction? Hard woods are used as structure components that are to sustain heavy loads or in components that are exposed to a harsh environment like exposure to water while softwood is used in areas that are protected from harsh environment and also when the timber is to be transformed into complex shapes. Plastics 27). What are the 2 elements that make up polymers? The two elements are Hydrogen and Carbon 28) Polymers are used extensively in construction applications- provide appropriate examples for nylon, polypropylene and polycarbonate. Polycarbons-polyethylene, polystyrene Nylon-rubber and shellac, Polypropylene- cellulose and DNA 29) Define the terms “elastic and plastic deformation”. Elastic deformation is where a material changes its shape when it is loaded but returns to the original shape when the load is released, on the other hand plastic deformation occurs when a material is deformed upon loading but when the load is released the material does not go to its original shape. 30) Draw a stress-strain curve and identify on the curve the areas for: a)The elastic region: between origin and B b)The plastic region: between yield point and brittle failure point c)The yield stress: stress at point B d)The ultimate tensile stress, stress at point d e)The elongation to failure: Elongation recorded after the yielding of the material f)The elastic (Young’s) Modulus. Gradient of line between origin and A Strain Part 3 – Loads and forces on buildings Discuss the different types of loads and forces which act on a building throughout its life cycle. When does gravity begin to affect the structure? The different types of load exerted on a building can be broadly be classified as live loads dead loads and superimposed loads. Dead loads are usually constant and may be due to the weight of the building itself. On the other hand live loads are those that can be movable and they are subject to fluctuation. The live loads can be due to equipment in the building, people, and stored goods like grains. Super-imposed loading – derived from the forces exerted onto the building by the climatic conditions prevailing. Describe compression and tension and give examples of where these can be found in structures. In structures like buildings the components that subjected to compression are the pillars of the houses. The lower parts of the beams are usually under tension Part 4 – Legislation What are the Building Regulations? What are the requirements of the Building Regulations? Discuss why buildings should comply with the Building Regulations. What do the Building Regulations cover? What building and building works are exempt from the Building Regulations? The Construction (Design and Management) Regulations 1994 This establishes mutual responsibility between the client, designer and builder for matters pertaining to the health and safety of site personnel throughout the duration of a construction project. The client has prime responsibility for appointment of a “project coordinator” (usually he architect) and a “principal contractor” (usually the main contractor), and for ensuring that both are adequately resourced, competent, and sufficiently informed of issues relating to the development. Buildings should comply with building regulations to make sure that building safe for occupation. The regulations also ensures that environmental issues are well taken care of during the construction period. Part 5 - Failure modes Identify and discuss the different types of failure modes that can occur within structures. What is the function of failure mode and effect analysis? Buckling Buckling is a failure mode characterized by a sudden failure of a structural member subjected to high compressive stresses where the actual compressive stress at the point of failure is less than the ultimate compressive stresses that the material is capable of withstanding. This mode of failure is also described as failure due to elastic instability. Creep Creep is the tendency of a solid material to slowly move or deform permanently under the influences of stresses. It occurs as a result of long term exposure to levels of stress that are below the yield strength of the material. Fatigue Fatigue is the progressive and localized structural damage that occurs when a material is subjected to cyclic loading. The maximum stress values are less than the ultimate tensile stress limit and may be below the yield stress limit of the material. Brittle Fracture In brittle fracture, no apparent plastic deformation takes place before fracture. In brittle crystalline materials, fracture can occur by cleavageas the result of tensile stress acting normal to crystallographic planes with low bonding (cleavage planes). In amorphous solids, by contrast, the lack of a crystalline structure results in a concordat fracture, with cracks proceeding normal to the applied tension. Impact In mechanics, an impact is a high force or shock applied over a short time period when two or more bodies collide. Such a force or acceleration usually has a greater effect than a lower force applied over a proportionally longer time period of time. The effect depends critically on the relative velocity of the bodies to one another. Part 6 - Additional Information Provide a glossary of technical terms used in the construction industry. A minimum of 40 words and their definitions must be given. Bidding Requirements: Written description of the procedures for submitting bids for construction of a project. BIM The acronym BIM is usually used to mean Building Information Model—the 3-D geometric model of a building made using software like Autodesk Revit, Graphisoft ArchiCad, or Bentley Architecture. Bridging Project delivery method in which the owner hires a design professional to perform conceptual and preliminary design Code Authorities Government and other agents that provide permits after approving relevant documents. Conceptual Documents The documents an owner or his design professional prepares to give instructions to a design-builder about how to design the project. Construction Documents: The documents describing what to build and how to build it. These usually are drawings and specifications. For small, simple projects, the specifications may actually be placed on the drawings. Construction Manager: charged with coordination and scheduling of contractors. Constructor Any entity performing construction. Contract Documents The documents describing the contractor's obligations. These include the construction documents and the contractual requirements. Contractor: Any entity who has a contractual relationship with another entity. In construction, the term contractor usually refers to a general contractor, who is the main contractor that the owner has a contract with (also known as a "prime" contractor). Contractual Requirements: The agreement between the two parties and the conditions of the contract. Descriptive Specifications: Construction specifications written to require certain products with specific physical characteristics. The specifier has already decided that the specified product meets functional needs. Design-Bid-Build: Project delivery method in which the owner hires a design professional to design the project and prepare construction documents, which are then issued to solicit bids from constructors. The owner-constructor contract is usually based on a lump sum fixed price. Design-Build: Project delivery method in which the owner hires a single entity to perform both design and construction. Design-Builder: Any single entity with which an owner or prospective owner contracts to perform both design and construction Design Criteria: The requirements of the owner and any regulatory agencies having jurisdiction. Designer: A design professional appropriate to the type of work being designed Drawings Construction drawings show where to build the project, sizes, shapes, and which products to use where. Facility: The preferred term for the result of a construction project. Outline Specifications: Very short product specifications, usually for purposes of owner review, estimator information, or financing agency approval. Owner: The person or entity that owns the facility or will own the facility once it is completed. Performance Requirements Statements regarding the performance of a facility, the built elements (parts) of a facility or the products the built elements are made of Performance Specifications: Specifications written to require certain functional characteristics; applies to entire facilities, parts of facilities (built elements), and products (materials and equipment). Prescriptive Specifications: Construction specifications written to require certain products with specific physical characteristics. Project Record Documents Construction drawings annotated to show all changes made during construction. In some cases, construction specifications annotated to show changes, substitutions, and products actually installed. Proposal Documents In a design-build situation, the design-builder's proposal describing what he intends to construct for the owner. It includes scope, time, cost, and quality information. If the owner has prepared an RFP, the proposal documents incorporate the RFP by reference and add any other material necessary. Proprietary Specifications Construction specifications written by referencing specific products by manufacturer and brand or model name; applies to materials and equipment. Regulatory Agencies Governmental jurisdictions or departments that issue laws, ordinances, and other regulations that design and construction must comply with. Request for Proposal (RFP) In a design-build situation, the RFP is the owner's document that explains what is required and how to make a proposal. An RFP usually includes: REFERENCES Akintunde E.O., 2008 Engineering Properties of Locally Manufactured Burnt Brick Pavers forAgrarian and Rural Earth Roads. American Journal of Applied Sciences 5 (10): 1348-1351, 2008 Available at: http://www.scipub.org/fulltext/ajas/ajas5101348-1351.pdf Accessed 10, May 2010 Consultation paper (2009) Removal of restrictions on the self-certification of the installation of combustion appliances: Helmenstine, A. M., 2010. Portland cement. Cement and Concrete Basics Available at: http://www.cement.org/basics/concretebasics_aggregate.asp Accessed 10, May 2010 Planning, building and the environment: Building Regulations Available at: http://www.communities.gov.uk/planningandbuilding/buildingregulations/ Accessed 10, May 2010 Property clinic, 2010. Planning, bricks and mortar and points of law http://www.telegraph.co.uk/property/propertyadvice/ Tsiskreli G. D.  and Dzhavakhidze A. N.,  1970. Granular composition of aggregate Available at: http://www.springerlink.com/content/g05128645382t94g/ Accessed 10, May 2010 Class notes.FV1207 Construction Technology Class notes. Foundations Class notes: Failure modes Class notes: Materials Read More