جستجوی مقالات مرتبط با کلیدواژه "ارزیابی چرخه حیات" در نشریات گروه "عمران"

With the increasing population and decreasing of earth's resources and the pollution of water, soil and air in the last few decades, environmental problems have become more visible than before. One of these problems is the excessive use of resources and excessive production of waste. Therefore, important measures have been taken in this field in recent decades, which are mostly offered in engineering and waste management. One of the important management strategies that have been implemented in this field is source reduction (reduction of produced waste in order to preserve resources and reduce waste) as the main goal and in the next stages recycling waste into the life cycle and preventing its burial through Material-energy recycling. WARM model (waste reduction model) is a tool for managers in this field, which is a road map for managers who make decisions for the future of waste management of a city or a country. This model is able to compare different management scenarios with the current situation. In this study, a proposed plan for the waste management of Tehran province for a 20-year perspective is presented in order to reduce the landfill by 30%. All input items are the default WARM model, and according to the available information and schematically, after examining several scenarios with regard to the composition of Tehran's waste and comparing them, a decision has been made about the optimal scenario.

Traditional patterns could be an effective solution for water consumption and pollution-related problems in the construction industry. However, the water footprint of traditional buildings in Iran has not been investigated. Iran has rich experience in constructing traditional buildings. This paper presents a comprehensive analysis of the grey and blue water footprints of the construction of traditional buildings in Iran with emphasis on different climate zones. The results are compared with modern buildings (concrete and steel). High-quality data related to 11 materials factories and 34 traditional buildings (stone, wood, clay, and brick) are presented. Blue and grey water footprints of building materialization are calculated using the water footprint network and life cycle assessment methods. The focus is on the structures of buildings. The grey and blue water footprints of modern structures are 327 times and 1.5 times larger than the grey and blue water footprints of traditional structures, respectively. Steel and cement production are influential parameters in the greywater footprint of modern structures. Employee meals have the greatest impact on the water footprint of traditional structures. The blue water footprint dominates the water footprint of traditional structures, which is 2.26 times larger than the greywater footprint. Stone structures have a blue water footprint of 0.85 m3/m2, which is dominated by the blue water footprint of employees' food (38.82%) at construction sites. They have a smaller blue water footprint than adobe and brick structures (1.41 - 1.42 m3/m2) and are close to the water footprint of wooden structures. The water footprint of brick structures is mainly influenced by the energy used (57.04%) for brick production. On the other hand, the greywater footprint dominates the blue water footprint of modern structures, which is 99.61 times larger than the blue water footprint. Steel structures have a blue water footprint of 1.86 m3/m2 and a greywater footprint of 208 m3/m2, the main pollutant of which is cadmium. Concrete structures have a blue water footprint of 1.60 m3/m2 and a greywater footprint of 137 m3/m2, with mercury as the main pollutant. From the water footprint viewpoint, it is better to use concrete structures than steel structures if both have suitable properties for the conditions they are used in. According to the results, the non-use of traditional buildings leads to an increase in water consumption and pollution.

In today's world, Environmental life cycle assessment is recognized as one of the complete methods for assessing the environmental impact of buildings. This study aimed to select the best way for assessing the environmental impact of life cycle in high-rise construction with full coverage of environmental impact classification. In this study, seven important categories of environmental impacts were analyzed in eight widely used life cycle assessment method using SPSS software, and finally, the ReCiPe method was selected as the most appropriate method. This method has then been studied for 16 high consumption materials in a residential building of construction phase in Tehran. Conclusion In this study, after comparing the midpoint and endpoint approaches using the ReCiPe method, the midpoint results are comprehensive while the endpoint results are brief. However, the endpoint approach provides more information on the environmental damage that should be considered to use a midpoint supplement. This study's findings can help project designers and builders before the construction of high-rise residential projects by estimating the environmental impact at the level of two approaches in selecting environmentally friendly materials. It should be noted that any misuse of these two approaches may affect the evaluation results and lead to misleading findings.

As the population and urbanization increase, policymakers consider urban water management more often; however, these policies can positively and negatively affect the urban water system. In recent years, following the increase in the water crisis in Isfahan province, pressure management has been applied to reduce access to water as a new water demand management policy in different cities of this province. The present study investigates the environmental effects of such policy in the new city of Baharestan (Isfahan province) during the 2018-2036 period, using a life cycle approach and different percentages of available water shortages. SimaPro software is used to conduct the life cycle assessment for processes such as network failure and energy consumption at the pumping station. The life cycle assessment is performed based on the conditions of the study area. The results show that significant part of the environmental effects in the water supply and distribution network is caused by network failures, which, compared to energy consumption, have many effects on most midpoint and endpoint environmental effects. So that the endpoint environmental effects of network failures are, on average, 2.2 times greater than that of pumping systems. The water distribution network and pumping system can minimize their environmental impact by implementing a pressure management policy. With pressure management, the endpoint environmental effects in both short-term and long-term scenarios are reduced by 14.7% and 20.2%, respectively.

Construction industry has been one of the most energy and material consuming industries in recent years. Environmental assessment of construction methods that includes energy consumption and emission release are important for implementation of improvement option to life cycle of construction. Despite the significant effect of selecting appropriate method on reducing amount of material, energy and emission, the studies often do not consider or incompletely model the environmental impact. The research has studied the energy consumption and carbon emission of two conventional and industrial methods of construction for concrete buildings: in-situ concrete and pre-cast concrete structural methods. This study has figured out how implementing precast concrete structure affects on environmental sustainability of the construction process. In addition the features of construction methods that can help the designer to achieve more sustainability have been assessed. The model developed to use the life cycle assessment (LCA) as a comprehensive sustainability methodology to quantify the environmental impact of several phases of building construction from extraction of raw materials to end of construction phase (cradle to gate). To investigate the environmental impact of each construction method two designed concrete structures with in-situ and precast elements modeled in building information modeling (BIM) and linked to the designed spread sheet.
Extracted results indicated using the high strength concrete for precast concrete structure, just in construction periods, is an effective way that reduces energy consumption of process and decreases carbon dioxide but in manufacturing process precast concrete consumes more energy and emits more carbon to environment. In Recognition of different features of energy consumption, material use and emission release of proposed method of construction, assist the project team in better decision making from environmental impact point of view and enable designers to provide recommendations toward achieving sustainable construction methods.

Solid Waste is one of the unavoidable products of every society that necessitates the establishment of municipal solid waste management (MSWM) system. One of the most important parts that could play an important role in promoting municipal waste management system is waste disposal method. Selecting appropriate waste disposal method is a complicated and multi criteria issue that should be considered regarding environmental, social, economic and technological aspects [1]. The aim of this study was to compare different scenarios of municipal solid waste disposal options in terms of environmental and economic and select the best scenario using Life Cycle Assessment (LCA) approach. In accordance with the ISO standard ISO - 14044 (2006), an LCA consists of four interrelated phases (Fig. 1) [2], and are presented as follows: