How the Initial Rate of Absorption Affects the Bond between Bicks and the Mortar - Assignment Example

The Running Head: Calculation     Your name:   Course name:             Professors’ name: Date: Part 1 Density Q.1. calculates the density of the following and arranges them in descending order? Density= Mass/Volume a. 7920kg/3.6m (square) = 2200 kg/m3 b. 0.01x1, 000,000/10=1000 kg/m3. c. 7800/3.2x0.05x0.075= 650,000 kg/m3. d. 160/2=80 kg/m3 650,000 kg/m (square) (first) 2200 kg/m(square) 1000 kg/m(square) 80 kg/m(square) (last) Q2. Volume: 1.6x0.16x0.1= 0.0256m3 Bulk density: 2100kgm3 Density= 7830kgm-3 x 2 =15660kgm-3/1000 =15.66kgm3 2100-15.660 =2084.34kgm-3 Mass= Density x Volume 2084x0.0256=53.38/2=26.67kg Q3. Define the terms “Bulk density” and “Solid Density”. Bulk density: can be defined as the weight per unit volume of material, this density is usually used for powders or pellets, including the voids in a bulk sample of the material (Fujii 2004, p.12). Solid density is the weight of a fixed volume of a material or matter (Fujii 2004, p.12). Natural Stones Q4. Identify the three classes of stones Natural stones are divided into 3 groups: igneous rocks or sedimentary rock or metamorphic rocks. Igneous rocks: The natures of these rocks are hard and crystalline and they make up most of rocks found on the earth surface. These rocks were formed as results of cooling of hot molten magma from the volcanic eruption. Examples of these rocks are granites and quartz (Graham 2004, p.2). Sedimentary rock: Examples of stones which fall under this category are sandstones and limestones. They are formed through weathering and erosion of pre historical rocks. These rocks have natural holes which will allow fluids like rain to enter into the rocks. These rocks are not durable because the usually disintegrate because of many factors (Graham 2004, p.2). Metamorphic rocks: these rocks have been formed as a result of alteration of other rocks and this is as results of heat and pressure. These rocks cannot be used in construction because they are not durable (Graham 2004, p.2). Q.5. which rock has the greatest percentage porosity? Sedimentary rocks: The shapes of these rocks are smaller and round in shape because of continues disintegration due other factors such as rain and pressure (Graham 2004, p.3). Q.6 Provide an example of 1 type of stone from the rock classes – metamorphic, igneous and sedimentary and, Metamorphic rocks: gneiss and slate. Igneous rocks: granites and quartz Sedimentary rocks: sandstone, and Metamorphic rocks: gneiss and slate is used in construction Q7. From your results answer the question: “Does a high porosity value increase or decrease the water absorption coefficient?” High porosity decreases the value of water absorption in rocks, while low porosity increases water absorption in rocks. Q8. Define the terms “Initial rate of absorption” and the term “capillary action” and the affect that pore size will have on them. Initial rate of absorption, this is the amount of water which can be absorbed by any material until it reaches saturation- cannot absorb more than it can handle, while capillary action is the tendency of a solid material to absorb or attract-within it pores, narrow tubes- liquid, in other words it is the intermolecular attraction within the liquid (water) and solid material (rocks) (Graham 2004, p.6). Q9. How does initial rate of absorption affect the bond between bricks and the mortar? Those bricks with higher initial rate of absorption will have weaker bonds; they will be readily disintegrated easily, while those bricks with lower rate of absorption will have strong bonds; their disintegration will not be easy (Graham 2004, p.6). Q10. Water absorption is an important factor in the durability of a brick. State two adverse conditions that could arise from excess water in bricks. When there is excessive water in bricks the level of saturation may be reached and the brick starts to disintegrate, secondly the chemical factor of that brick might be changed (Graham 2004, p.2). Metals Q11. What affect does the carbon content have on the ductile/ brittleness properties of mild steel? Iron ore or ‘cast iron’ is brittle in nature because of high concentration of carbon, phosphorus and sulpur content. In order to make steel to be strong (not brittle) carbon and other minerals should be removed, because (Bloxam 1999,p.24). Q12. Describe briefly, the following heat treatment processes: a) Annealing: this is when a metal is heated to a specific temperature and then allowed to cool slowly, this means the metal will be soft and can be cut and shaped more easily (Bloxam 1999,p.34). b) Normalizing: this heat treatment process is applicable in ferrous metals only, after the metal has been heated with higher temperature it is removed from the furnace for air cooling. The reasons for this are to remove the internal stress which is induces as result of heat treatment, welding etc (Bloxam 1999,p.34). c) Quenching: this is a phase in transformation of metal and it takes place during the heating of steel or cooling process. This technique is use to increase the hardness of steel, the process involve dissolving alloying metals into base metal; so the alloy metals will be trapped within the crystal structure and it will not allow them to precipitate out separately (Bloxam 1999,p.34). Q13. Explain why high-carbon steels would not be suitable for reinforcement for concrete. increases brittleness and reduces weldability in metallic materials. Corrosion Q14. Electrolytes this is any substance that contain free ions and it makes the substance to be electrically conductive. When you put metal in an electrolyte, metal corrosion will take place because electrolyte will help provide oxygen to the anode of the metal, as oxygen combines with the metal, electrons are liberated causing corrosion (Bloxam 1999,p.64). Q15. Define the term “corrosion”. Explain the terms “Cathodic Protection” and “Sacrificial Anode”. Corrosion: this is degradation of metal by chemical means, metal usually react with chemicals that are found in the environment and returns to the combined form- rust is a form of iron oxide. Cathodic Protection: this is a electrochemical process of controlling corrosion in metals. This process usually minimizes the anodic dissolution of structure of metal, when you reduce the electrical potential energy difference that exist between the anodic and cathodic sites that is found on the surface of the metal that has been placed into a conductive electrolyte. There are two different methods that can be used to apply cathodic protection in metals: sacrificial (galvanic) anodes and impressed current (rectifier) cathodic protection (Bloxam 1999,p.54). Sacrificial Anode: is made up of an alloy of magnesium, zinc or aluminum, different alloy will use different electrolytes such as soil or seawater. Different sacrificial anode will give different sources of cathodic protection current as a result of higher electrical potential energy of the anode in relationship to the structure it intended to protect (Bloxam 1999, p.54). Q16. What affect does pH have on corrosion? Between pH 4 to pH 10, metal corrosion will be independent of the pH of the solution in contact with the metal, this is because the rate of metal corrosion will be depend largely on the rate of oxygen which reacts with absorbed atomic hydrogen, this will depolarize the surface of metal which will allow reduction reaction to continue. For pH which is below 4.0, ferrous oxide (FeO0 will be soluble, in other words, the oxide formed will dissolve than being deposed on the metal surface in the form of a film. For pH above 10, the rate of corrosion is observed to fall as the pH is increases (Bloxam 1999, p.28). Cement, concrete and cement replacements Q17. Briefly explain what cement replacements are and discuss why they are used in the construction industry. Cement industries in the world produce significant greenhouse gases on their plants, there is an increase in demand for cement in construction industries worldwide and this means more pollution of environment. There is need for cement replacement technology that will reduce greenhouse gas emissions in the construction industries. One way you can replace cement is to recycle cement waste that is being used in construction industries (Mindess, 2002, p.14). Q18. Briefly discuss why heat is produced when hydration occurs and explain why this relationship should change with differing cement / replacement mixes. Heat of hydration refers to the heat that is generated when there are chemical reactions between water and cement. The heat generated in this process will cause the concrete to first expand and then shrink as it cool off. If the temperature generated is restrained, then cracks will occur. The two factors which will determine excessive heat to be produced will be to pour large amount of cement or water and vice versa (Mindess, 2002, p.24). Q19. Portland cement can be vulnerable to attack from sulphates and chlorides, this problem can be reduced by using PFA or GGBS, why? GGBS (Ground Granulated Blastfurnace Slag) and PFA (Pulverized-Fuel Ash) are by products of industry and they are mostly used because they are environmentally friendly. On the other hand GGBS and PFA is being used to replace cement because of the following reasons: one, they are long term durability of concrete in terms of resistance to chloride and sulphate attacks, the heat of hydration which is a problem because of cracks in buildings is minimized, and lastly the structure which used these products will remain serviceable for longer period (Mindess, 2002,p.34). . Q20. Yes the amount of water will affect the strengths and durability of the concrete, this is because too much water will make excessive heat of hydration to be produced, at same time less water used will make the cement not to mix well and this will make a weaker bond. Aggregate Q21. List any three characteristics of concrete aggregate and discuss their influence on the properties of fresh concrete. Concrete aggregate are the materials which are use with cement to create concrete which is hard, strong and long lasting in nature. For concrete aggregate to be effective, it must be hard so that keeps its shape without deforming when it is used in concrete, aggregate must be clean, in other words it must be free of any chemicals, clays and any leached materials that will interact with the concrete; this may interfere with concrete aggregate (Mindess, 2002,p.54). Lastly, they should be strong because weak concrete aggregate will weaken the concrete. Q22 Define porosity? Explain how grain shape influences porosity. Would a well graded aggregate have a low or high porosity? Give reasons for your answer. Porosity is the level of air space between the soil particles, the shape of grain particles plays a role in porosity. Those grains which are packed on top of each other will have higher porosity than those grains shaped which are not packed together. While a mixture of different grain sizes will have lower porosity than that particle size of same materials. But the diameter of grain particles will not affect the porosity of the material (Mindess, 2002,p.54). . Q23. What affect will chloride salts have on reinforcing bar within in concrete and therefore on the concrete as a whole? Chlorides, including salts (sodium chloride) will accelerate corrosion of embedded steel rebar if the concentration of chloride is high. Chloride anions which are found in most mixtures will induce both pitting corrosion and generalized corrosion of steel reinforcements in most construction industries. For this reason during construction, one should use fresh water and the fine aggregates don’t contain traces of chlorides. Timber Q24. 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 and discuss the function of the cells identified. The difference between hardwood and softwoods trees is their difference in their cellular structures. Softwood has a simpler cellular structure while that of hard wood is complex. Cellular structure of a tree will help a person to determine the age of that tree (Scallan 1993, p. 23). Softwood hardwood Q25. Define the term “coefficient of thermal expansion”. Coefficient of thermal expansion can be referred to as the degree of expansion of materials which is divided by the change in temperature of the same material. Coefficient of thermal expansion will varies with temperature. When environmental temperature is increased, the wood will expand and vice versa and this will have an effect on the wood itself; cracks may appear as a results of varying temperature (Laidler 2003, p.12). Q26. Define the terms “Modulus of Elasticity” and “Modulus of Rupture” for both a hard wood and softwood. Calculate the “Modulus of Rupture” using the figures obtained from the experiment you carried out. Modulus of Rupture (Nmm2) = 1.5 P x L / Width x depth2 Where: P = Load at failure (N) L = Length between sample supports (mm) “Modulus of Rupture” this refers to the ability of a material to resist deformation under a load, while Elasticity is the ability of a material to restore to its original shape after it has been distorted with a load (Laidler 2003, p.22). Q27.Draw and label a diagram to show where the forces of compression and tension acting would act on a timber sample during the static bending test and state on which side did failure occur? Plastics 28) Draw a schematic of the structure of the following monomers: a) Nylon, b) Polypropylene, c) Polycarbonate. 29) Discuss the hazards of polymers/ plastics in fire situations. These materials usually produce toxic which are harmful to human body, they are largely made of carbon and can deprive someone of oxygen during fire situation because carbon will mix with oxygen to form carbon dioxide. 30) Draw a stress-strain curve and identify on the curve the areas for: g) Define the terms “elastic and plastic deformation”. Elastic refers to a stretchy material and can return to it original form after it has been stretched and plastic deformation: when force is applied on the material it will undergo non reversible changes of shape, for example a metal or plastic (Laidler 2003, p.53). Part 2 Building Process Project manager this is a person who is responsible for the accomplishing the objectives of the project. Some key responsibilities for a project manager include creating clear and attainable objectives of the project, he/she builds the requirement of the project, and he/she also manages the triple constraint for the project. This includes cost, time and qualit (Bezelga 1990, p.29). Construction manager, he/she makes sure the project is brought into successful completion within the allocated time frame. He/she in charge of overall planning of the project, he/she coordinate the project, and he/she control the project from it inception to its completion within the authorized cost and to the required quality standards (Bezelga 1990, p.29). Project Architect, his/her main responsibility is to oversee the architectural aspects of the development of the design- production of construction plans and specification needed. With the consultation with other personnel involved in the project, also, the project architect may take the responsibility to perform the management tasks that is related to the running of the Architectural project (Bezelga 1990, p.29). . Design Engineer, he/she make sure to take care the inner working of a design which is involved in construction, he usually work with a team of engineers to develop the preliminary design which is the most critical part in construction industry (Bezelga 1990, p.29). Design process For any construction process there must be a need; the need here can be defined as the market research. At any time a need should be defined in a highly detailed way such as in writing. For any design process, there should be research on the project before any work begins, the person in charge of design process should study existing solution and concepts, this way he/she will be able to evaluate the weakness and strengths of that process; search engines are helpful for this task, but relevant books can be found in libraries. Concept, based on your research, you can choose the relevant concept that suit you, for example, the person in charge of the process can choose to create a draft of the plan by pen and paper or use simple vector graphics programs such as CAD, or he/she can choose Diesel or Stirling engines for stationary electric generators. Planning, for any process to be completed, it should involve planning (Bezelga 1990, p.39). Site Investigation This is the process of gathering of information about a particular site where proposed project will be undertaken. Also, site investigator he/she is able to determine whether there is contamination present at the site and he/she is able to collect data for purpose of risk assessment at the proposed site; this investigation at the sites is normally carried out in stages of the project. Deskstudy, this is the first phase in investigation, its involves collecting of relevant information from a variety of sources in the construction site. This relevant information includes geological and hydrological setting of the construction site and the historical uses of the construction site. Subsequent, site walkover: it provide detailed of the conditions of the construction site such as if there is any potential contamination and site environmental practices. The second phase in site investigation involves soil, water and gas sample analysis, whether the land in question is used for farming or intended to be used for other purposes such as hospital building so on or the site in question can impact negatively on the environment (Bezelga 1990, p.59). Foundations A deep foundation is embedded into the ground. In other words a shallow foundation will transfer building loads near the surface of the earth, rather than to subsurface layers as does a deep foundation. Example of: Shallow foundations: Spread footing, a spread footing is used to help support the foundation or piers below a building. Mat-slab Mat-slab foundations are used to distribute heavy column and wall loads across the entire building area, to lower the contact pressure compared to conventional spread footings. Slab-on-grade Slab foundation that is to serve as the foundation for the structure is formed from a mold set into the ground. Deep Foundation: Helical Foundation Impact driven pile Foundation drilled shafts Foundation While deep foundation consists of helical and impact driven pile, drilled shafts, caissons and piers in the house construction (Brown 1996,p.12). Foundation failure can be brought about as results of many factors, some of the factors include foundation movement as a result of shrinking of clays caused as a result of changes in moisture content in the clay, compression of a soft layer in the ground, soil softening, frost heave, vibration from nearby construction sites and improper back filling. Also, inadequate design of basement walls and footing before the main construction is accounting for 85 per cent of all the problems that is associated with foundation failure (Brown 1996,p.13). Foundation failures are usually identified into two broad classes: lateral pressure and differential settlement. Flooding of basement have been recognized to be a serious problem in foundation failure and this should be prevented at all cost, during construction right construction materials should be used and this include initial planning of the house. Bricks swelling can be prevented if clay backfill in making bricks should be replaced with gravels or any other non swelling material (Brown 1996,p.16). Ventilation Ventilations is a process of “changing” of air in a building, it is used to remove that air which is unpleasant and excessive moisture in a placed which is installed, it also help the interior of a building air to circulate, thus prevent stagnation of air in the building. Ventilation is categorized into two groups: Mechanical ventilation; uses of powered equipment, e.g. fans and blowers, to move air or control air quality inside a building; excess humidity, odors and contaminants is being controlled via dilution. Natural ventilation; uses natural ways of regulate ventilating a place with outside air without using fans or powered equipments. The uses of ventilations are as follows: to keep flammable gases in a company below their flammable limit, to keep the flow of air movement at a recommended level, to reduce odors, to control dusts and other particles found in a place and to limit carbon dioxide which might build up in a particular place (Butler 2009,p.24). . Ventilation requirement Those buildings with habitable rooms and toilets are required to be vented by natural or mechanical means. In natural ventilations habitable rooms in a building will require one or more ventilation openings and the total area to be ventilated must not be less that 1/20 th, floors areas of the room and some part of the room in a building must be more than 1.7 meters above the floor level. When using mechanical means to ventilate a building, one air change/hour must provided to habitable rooms inside the building and 3 air changes/hour to bathrooms and kitchens (Butler 2009,p.25). Performance based ventilations; this is when a ventilation machine is working to its optimum level. Part 3 Types of loads and forces which act on a building throughout its life cycle. In a building, we can define force as any agent that will cause stress or compression in the building. Apart from forces of gravity that will push the building down, there are two types of forces that will be experienced in a building: Pull force -> Stress effect Push force -> Compression effect. Loads which act on the building are either static loads ( not moving) or dynamic loads, example of static loads are the weight of the building beam, cement, glasses, while dynamic loads in a building comprises of people weights, furniture, desks, tables and anything that is inside the building (Fujii 2004,p.34). Describe compression and tension forces Tension forces; is a pulling force that will try to stretch or lengthen part of the building, for example, the beams of a building. While compression forces; will try to shorten part of a building, for example roof of a building (Fujii 2004, p.54). Part 4 Failure modes Briefly discuss the main aspects of behavior of plastics, steel, concrete and wood in fire conditions. When plastics and wood are exposed to wood, both products are mainly made up of carbon and they will burn. Wood will burn to ashes, while plastic will sublime. When metal is put in fire, noting will happen until it has reach that temperature when the metal will melt to liquid, but if it is allowed to cool down, it will return to its original form. Nothing will happen when concrete is exposed to fire (Press 2003,p.24). Things can fail in a variety of different ways and this can be as a result of the component geometry, or direction of load, or environmental conditions. By understand how a component can fail, engineers that is in charge of designing the component will be able to minimize the failure of that component (Press 2003,p.24). There are various modes for failure of a component, such as: Corrosion; these is chemical alteration of the material and this is as a result of environmental exposure to corrosive elements such as water. For example, iron or steel metals. Creep; this is slow deformation of a material over a period of time; this is as a result of applied loads to that material and to some extent increased temperature (Press 2003,p.24). Fatigue; this is the reduction in the ultimate strength of the material and this might be as a result of cyclic loading of a part of that material; micro deformation of the material can occur to that material. Fracture; material in question having cracks, with time those cracks will become critical and the item will break (Press 2003,p.24). Thermal shock; this will occur as a result of the component moving from extreme temperature to another, for example if metal is suddenly cooled with cold water. Wear; this is the gradual disintegration of a material and this can be as a result of environmental effects or the material rubbing against each other (Press 2003,p.24). Failure Modes and Effects Analysis (FMEA); this is a method which can be used to analyze potential problem of a component early during its development cycle, FMEA is done because it will be easier to make correct to the component, thereby enhancing reliability through design. It main use of FMEA is to identify failure modes of components and to mitigate the failure on time if it occurs. Part 5 Legislation Discuss the importance of the Building Regulations, identifying the different Approved documents and highlight the main points of guidance given in each. Building codes, these are rules and regulations that have been put in place to provide a means of safeguarding life and protect the public welfare during designing, construction and the materials which are used in the construction- including fire performance (Vitale 2007,p.23). The rules that are found in building regulations plans are necessary so that to provide a notice to the local authority building control service that is found in the country. The codes have put in place to safeguard life and at same time protect the public through regulating the design and materials that will be used in the construction of the building. Some of the building documents that will be used are: title deed of the land, building plan, environment impact assessment document, and the document that you have given a go ahead to construct the house (Vitale 2007,p.23). Part 6 Additional Information B-Bidding Requirements BIM- Building Information Model Code Authorities Conceptual Documents Construction Documents Construction Manager Construction Manager Constructor Contract Documents Contractor Contractual Requirements Reference List Bezelga, A. (1990). Management, Quality and Economics in Building. London, FN Spon Publisher. Bloxam, C. (1999). Metals, their properties and treatment. London, Appleton and Co. Publisher. Brown, R. (1996). Practical foundation engineering handbook. London, McGraw-Hill Publisher. Butler, W. (2009). Ventilation of Buildings. London, BiblioLife Publisher Fujii, K. (2004). Density, London, Institute of Physics Publisher. Graham, I. (2004). Rocks: A Resource Our World Depends on. London, Heinemann Library Publisher. Laidler, J. (2003). Physical chemistry. London, Houghton Mifflin Publisher. Mindess, S. (2002). Cement and concrete: trends and challenges. New York, American Ceramic Society Publisher. Scallan, M. (1993). Timber and its composite products: their benefits as interior surfaces. South Wales, University of New South Wales. Read More