International Journal of Sustainable Built Environment最新文献

Environment is subject to many pressures. Climate change and the global warming constitute an additional pressure. The “climate change” and its consequences are more important than other challenges in 21 century. The global temperature has risen by more than 2.5 °C in recent years. Similarly, a global temperature rise of more than 2.5 °C increases the absolute number of people at risk of hunger by 80 million. Recent estimates indicate that 25% of the world’s mammals and 12% of birds are at significant risk of global extinction. The main reason for global warming is CO₂ increase that is obtained from burn reaction. According to California university, CO₂ emissions result from emissions of: transportation 49%, electricity 30%, industrial 11%, residential 7% and commercial 3%. In the mean time, CO₂ concentration is 360 ppm even, if severity plan will be applied as per Kyoto protocol it will arrive at 450–650 ppm in 2100. Thus, there is a global resolution for declining CO₂ emission and one of the practical approaches is CO₂ decreasing in electricity sector. Each of energies has strengths and weaknesses and we focus more on nuclear energy because its CO₂ emission is zero. It should be added, in most of countries there is a tax for gas e.g. in the U.K. 3.4$/gallon and in Italy 2.53 $/gallon, so fossil fuel is an income for their governments but for nuclear energy government pays subsidies. Therefore it is not possible to debate about it before removing tax and subsidy. In recent years, it has been stated about tax on carbon production that it is a step forward to low carbon economy and finding the real cost of fossil fuel with attention to external costs in the environment.

Concrete is the most widely used construction material in the world. Cement is the major manufactured material used in the production of concrete. It is an established fact that the manufacturing of one tonne of cement produces about one tonne of CO₂, which is a major Green House Gas (GHG), contributing to Global Warming, Climate Change and Ozone layer depletion. In this paper, the environmental impact of cement manufacturing has been assessed on the basis of literature review. The use of Supplementary Cementitious Materials (SCMs) such as Pulverized Fly Ash (PFA) and Ground Granulated Blast Furnace Slag (GGBS), Rice Husk Ash (RHA) and Silica Fumes (SF) have been used for reducing the weight of cement in the concrete mixes to achieve, the desired compressive strength of concrete for use in construction projects. Various trial mixes have been used with partial substitution of cement with PFA and GGBFS and SF to achieve the desired high strength concrete for structural uses. The addition of the SCM has reduced the cement proportion in concrete, thereby making it relatively sustainable. The results have been assessed on the basis of reduction in the embodied energy of the concrete. The paper presents a holistic review of concrete by using binary cement, incorporating Ground Granulated Blast furnace Slag (GGBS), Pulverized Fly Ash (PFA) and Silica Fumes (SF).

This paper is to study the unauthorized urban neighborhoods, which cause critical multifaceted difficulties. It explores the reasons that have resulted in the unauthorized urban neighborhoods generally and in Chabahar city particularly. This paper has performed a case study to analyze the socioeconomic, spatial, skeletal, and functional effects of the illegal neighborhoods in the Chabahar city with the help of academic methods and field observations. It reviews various theoretical ideas and experiences could assist the rehabilitation and reconstructing of the unauthorized urban districts. It discusses optimal strategic regional/urban revitalization planning procedures to solve the problems in Chabahar. Finally, this paper suggests a renewal/rebuilding possible development program, including eight mother projects. The results of the renewal program will be substituted with the present informal and eroded neighborhoods in the city. The renewal program made progress in both physical features of the city and urban life quality indicators simultaneously. The model suggested by this paper will be feasible in similar regions everywhere.

The study examined the factors responsible for the spatial variation in housing quality across the 36 states and the Federal Capital Territory in Nigeria using 33 housing characteristics. The data used are the 2006 Housing Characteristics and Amenities tables which were sourced from Nigeria’s National Population Commission (National Population Commission, 2006). Principal Component Analysis extracted three components. Component 1 accounting for 38% has electricity, water closet toilet, hygienic sources of water and high quality roofing, walling and flooring materials highly loaded on it. Component 2 (31%) comprised inferior walling, roofing and flooring materials, pit toilet, traditional and semi-detached house types, while component 3 (7%) had mainly zinc wall and public toilet highly loaded on it. Using these factor loadings as variables in discriminant analysis, three distinct regions of differing housing quality emerged corresponding to the western, eastern and northern geographical regions of the country with 97.3% of the states correctly classified and with the western (high) and northern (low) states at the opposite ends of the quality scale. It is recommended that non-conforming buildings, particularly, residential, and insanitary environment should be put in check through very strict and proactive enforcement of development control edicts and sanitary laws.

Climate change is expected to increase both the magnitude and frequency of extreme precipitation events, which may lead to more intense and frequent river flooding. This study aims to assess the flood hazard potential under climate change scenarios in Yang River Basin of Thailand. A physically-based distributed hydrological model, Block-wise use of TOPMODEL using Muskingum-Cunge flow routing (BTOPMC) and hydraulic model, HEC-RAS was used to simulate the floods under future climate scenarios. Future climate scenarios were constructed from the bias corrected outputs of three General Circulation Models (GCMs) for 2020s, 2050s and 2080s. Results show that basin will get warmer and wetter in future. Both the minimum and maximum temperature of the basin is projected to increase in future. Similarly average annual rainfall is also projected to increase in future, higher in near future and lower in far future. The extreme runoff pattern and synthetic inflow hydrographs for 25, 50 and 100 year return flood were derived from an extreme flood of 2007 which were then fed into HEC-RAS model to generate the flood inundation maps in the basin. The intensity of annual floods is expected increase for both RCP 4.5 and 8.5 scenarios. Compared to the baseline period, an additional 60 km² area of basin is projected to be flooded with the return period of 100 years. The results of this study will be helpful to formulate adaptation strategies to offset the negative impacts of flooding on different land use activities in Yang River Basin.

This work aimed to investigate effecting of using plastic waste as partial replacement of fine aggregate, on the fresh characteristics of self-compacting concrete (SSC). For this purpose, different self-compacting concrete mixes were designed at constant water-to-binder ratio of 0.32 and 520 kg/m³ of binder content. Class F fly ash was used as partial replacement of cement (30% by weight of cement). The six designated plastic waste contents of 0, 2.5, 5, 7.5, 10, and 12.5% and three different sized Plastic wastes (fine plastic wastes, coarse plastic wastes, and mixed plastic waste) were considered as experimental parameters. The workability properties of self-compacting concrete mixtures were performed regarding to slump flow diameter, T₅₀ slump flow time, V-funnel flow time, L-box height ratio, and L-box T₂₀ and T₄₀ flow times. The 28-day compressive strengths of self-compacting concretes were also measured. The experimental results of this work are showed that the plastic waste with the sizes and contents that used in this work can be used successfully as a fine aggregate in self-compacting concrete.