Question:
Assignment -2,
What is LCA?
- Give the definition of operational and embodied energy?
- How do you conduct an impact assessment?
- How do you conduct an LCA? Give the description with flow chart within 1000 words.
- What are the structural grading rule for Australian Timber? Give detail descriptions.
- What are the differences between visual stress grading and machine stress grading? Explain with figures.
- What are the factor effecting in brittle structure?
- What are the reasons for corrosion in steel structure and how can you prevent the structure from corrosion?
- What are the factors effecting in fatigue life on a steel structure? Explain with figure.
Answer:
Construction materials
Life-cycle assessment, (LCA), also referred to as life-cycle analysis or even life-cycle eco-balance among other names is a method which is used to assess the environmental impacts which are related with the stages of product life (Finnveden et al., 2009). The assessment is able to involve the analysis of the different stages which a product is able to pass through until it reaches its final product. That means from the analysis of the product from the raw material stages during extraction then the processing, manufacturing, distribution, usage, repairing and maintenance stages then the disposal or recycling stages. This process is key to analyze the products and it helps the designers of the different products to critique and analyze their products properly. Most importantly, this process is able to avoid narrow outlook on environmental issues in relation to the products. Some of the key environmental issues which are analyzed in this process revolve around the compilation of inventories, which are related to energy and material inputs and their impacts to environment when released. Moreover, this process is related to evaluation of the potential effects which are related to the identified product inputs and the effects of their release to the environment. Lastly, this process is able to interpret the result from the data derived from the different products stages in relation to the environment (Finnveden et al., 2009). This stages helps to derive an informed decision in dealing with the effects of the product life-cycle to ensure it enhance the environmental protection.
The main aim of LCA is to enhance the comparison of full range environmental impacts assigned to products and services through quantification of all inputs and outputs of material flows. It then goes to an extend of assessing the effects of material flows to the environment (Singh & Bakshi, 2009). The acquired information helps to improve the product processes , enhance policy support and enhance decision making in environmental conservation. The process aims to provide fair and holistic assessment of the product cycle processes to enhance proper environmental conservation. There are two key types of LCA, which include attributional LCA and consequential LCAs. Attributional LCAs looks to establish the burdens which are related with productions and use of products or which are related to a services at any given moment. On the other hand, consequential LCAs looks to identify any environmental consequences resulting from a decision or change of system which is under observation. It extends to monitoring of market and economic implications which are achieved due to a decision which is taken. Lastly, another key LCA which is under development is the social (Steinbach and Wellmer, 2010). This looks to analyze the social effects and can be seen as a complimentary to the environmental LCA.
- Give the definition of operational and embodied energy?
Green energy has to key aspects which are related. These are the aspect of green energy at the manufacturing or production method or the green energy at the application point. These two aspects are able to differentiate operational and embodied energy. Embodied energy is related with the cumulative energy which is used in extraction of raw materials, their manufacturing and transportation of the product to the final application destination (Adams, Connor and Ochsendorf, 2010). In other words, this is the energy which is consumed by all processes during the production stage. Nevertheless, the embodied energy does not include the operations and disposal energy produced during the product life-cycle. The operational energy is related to amount of energy a product is able to consume or use after it has been installed to the system or applied to it (Hamilton, 2011). Occupants and their usage of energy is able to contribute to the overall operational energy amount.
- How do you conduct an impact assessment?
Impact assessments are procedural and are able to follow a systematic procedure. This is because the processes on which the impact assessments are done a systematic in nature. The selection of impact categories is the first process which is carried out. The existence of the different impacts during the assessment is a key step which has to be identified earlier enough to ensure that the assessment has a specific goal to achieve. Category indicators and characterization models are developed at this stage to enhance the assessment criteria on the impact extend (Curran, 2011). Classification stage is the other stage which is followed when the impact assess men is being conducted. Inventory parameters are assigned different impact categories to enhance proper achievement of the results. Lastly, impact measurement is the last stage which is carried out during the conducting of the impact assessment. Specified methodologies are usually followed to ensure that impact measurement are well achieved. Recommendations on the impact assessment improvement is usually carried out at the end to ensure that the cons are mitigated to ensure that the enhancement of the different factors is achieved. The criteria of impact assessment ensures that different stages are able to monitor the different aspects of each process and come up with viable solution at the end of the assessment.
- How do you conduct an LCA?
There is a systematic way of conducting an LCA in order to achieve the set goals. As noted, an LCA can be conducted to Achieve different scopes and goals. This goals vary from different aspect such as the products being considered to the impacts and relation of processes and the environment (Cooper & Fava, 2006). Nevertheless, each LCA has a defined procedure which can be followed in order to achieve the set goals. The process of conducting an LCA starts with definition of goals and scope of the assessment. Th definition of the goals and scope is a key strategy mechanism, which is key for any LCA. This process defines the need and what need to be achieved at the end of the assessment period. The perfect elements of each LCA are addressed at this stage, whereby the relevant question are asked and their solution be searched. The needs to of the LCA are addressed since the key questions will aim at achieving the key goals and scope of the assessment (Malmqvist et al., 2011). Additionally, this area will ensure that the required sustainability of the assessment approach is achieved. In the aim of answering the questions raised, the process will look to use economical means to enhance the adoption.
Inventory analysis is another key step which is required during the conduction of the LCA. The elements assessment are placed on table and measured accordingly. Analysis of the depth of the product and the key measurement are done at this stage. This stage is able to enhance the understanding of the key elements of the product and the way to achieve the required goals. The inputs and output of the assessment are analyzed at this stage to enhance the achievement of the products assessment (Malmqvist et al., 2011). Data collection and verification in order to enhance adoption of the proper solution is carried through this stage. The inventory analysis is able to ensure that the elements of the products are well documented to enhance result derivation. The analysis of the different aspects of the all elements of the product process is well enhanced through the inventory analysis.
Life cycle impact assessment is another key step involved in the conducting of LCA. This stage ensures that the analysis of the process is well analyzed and the achievement of the key step is achieved. This step takes the inventory data and then conduct it to the required indicators in each of impact categories (Cooper & Fava, 2006). This key step ensures that the answers to the earlier questions are achieved. Moreover, interpretation of the data at any step is key to ensure that all the product elements are analyzed and correct solution is derived.
- What are the structural grading rule for Australian Timber? Give detail descriptions.
Structural grading of the timber is a key element in Australian category. Stress grades are key structural grading which is applied in grading of timber. F-grades have been used for a long time in the analysis of the structural grading of timber in Australia. The F grading is able to range from F2 to F34. The different gradings are able to define the different strength of timber.
- What are the differences between visual stress grading and machine stress grading? Explain with figures.
Visual grading is a key element where the analysis of the timber situations are analyzed from visual inspection. The visual stress grading is able to compose of what inspectors can see and then be able to identify the structural class which the timber is likely to lie. The visual grading is based on how the defects are able to affect the appearance of timber and their strength. The defects are able to result on the different uses which the timber can be used for.
Under machine stress grading, a machine is used to analyze the stiffness of the timber and therefore grade them according to the results regardless of their appearances. The machine normally bends the timber piece and uses the loose correlation between the stiffness and strength to grade the timber. Through the derivation of the stiffness parameter, other elements of timber can then be achieved such as tension, compression and shear strength of the timber. This makes this method more effective than the visual grading method.
What are the factor effecting in brittle structure?
Temperature changes is one of the key factors which affect the brittle structure. Each member and element has a specified temperature at which they can withstand at the exceeding of the temperature beyond that limit is able to affect the brittle structure of the material. Grain sizes of the different members are able to result to the brittleness of the member. Small grains are able to compact themselves more and therefore increasing the brittleness structure of the member (Ortner, 2008). Lastly, crystal strength of the individual grains determine the brittle structure of the whole member. Increase on the crystal strength of the grains results to an increased structural brittleness in the member. The effect of the structure is affected from the internal properties of the grains and this affect the brittle structure of the members.
- What are the reasons for corrosion in steel structure and how can you prevent the structure from corrosion?
Corrosion in steel is caused by presence of key elements which promote the development of the corrosion. One of the key reasons for corrosion to occur on steel is due to its reactivity (Whirlwind Team, 2015). Steel is a more reactive metal and this is a key factor which accelerates the corrosion process. In presence of oxygen and water, the reactivity of steel is able to accelerate the corrosion process. Secondly, presence of gases is able to accelerate the corrosion process of steel. Presence of air, moisture and steel section is able to offer an environment which the corrosion process occur. Additionally, presence of impurities is able to lead to corrosion on steel. These impurities are able to offer conducive environment where the corrosion process can occur. Lastly, electrolyte presence are able to accelerate the corrosion process on the steel structures.
There are different methods which can be applied to prevent corrosion on steel structures. Cathode protection is one of the methods. This method is able to alter electrode potential of the steel structure and making them lie on immune region where the process cannot occur. This process makes the steel structure stable and this unable to react with the elements which facilitate corrosion. Use of corrosion inhibitors is another key method to prevent corrosion on steel structure (Whirlwind Team, 2015). Presence of foreign molecules on the steel structure is able to affect the surface reaction. The inhibitors are able to either attached on the surface of steel structure or be absorbed directly to them.
- What are the factors effecting in fatigue life on a steel structure? Explain with figure.
Fatigue in steel structure is affected by different parameters. Stress application is one f the key factor which affect the fatigue life of steel structure. Loading the steel structure more than the required loading increases the stress factor and thus affecting the fatigue life. Fabrication and material properties is another key factor which affect the fatigue life of a steel structure (Stephens & Fuchs, 2009). Material hardness and fabrication nature is able to affect the fatigue life of the steel structure. Moreover, the environment were the steel structure is exposed to is able to affect the fatigue life. High temperature, presence of corrosive atmosphere and high humidity are able to reduce the fatigue life of a steel section. Lastly, geometry structure of the steel structure affects the fatigue life of the structure. Scratches and weld defects are able to reduce fatigue life of the steel structure.
References
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