International Journal of Sustainable Built Environment最新文献

This paper evaluates the economic, environmental, and social benefits of large-scale energy efficiency programs for new and existing buildings in Qatar. Using data obtained from detailed energy audits, several proven energy efficiency measures have been analyzed through optimized based analysis to assess their impact on the energy performance for both new and existing buildings in Qatar. Moreover, a bottom-up analysis approach is considered to quantify the multiple benefits for implementing large-scale building energy efficiency programs for the building stock in Qatar. In particular, a more stringent energy efficiency code for the new constructions and three energy retrofit levels for the existing buildings are considered in the analysis. A novel macro-economic analysis using the concept of energy productivity is used to assess the cost-benefit of large-scale energy efficiency programs in Qatar. It is determined that the implementation of a government funded large-scale energy retrofit program for the existing building stock is highly cost-effective in Qatar. In particular, it is found that a large-scale energy efficiency retrofit program of existing buildings can provide a reduction of 11,000 GWh in annual electricity consumption and 2500 MW in peak demand as well as over 5400 kilo-ton per year in carbon emissions. In addition, over 4000 jobs per year can be created when this large-scale energy retrofit program is implemented over 10-year period.

In order to arrest the incidence of global warming brought about by the emission of greenhouse gases notably CO₂ into the atmosphere, the use of materials that can substitute the material responsible for greenhouse gases is being promoted world-wide. One of these is rice husk ash (RHA) which has been found suitable by researchers to partially replace Portland cement in the production of concrete. This paper presents a comprehensive and up-to-date review of the work of numerous researchers on structure and properties of concrete containing rice husk ash (RHA) as partial replacement of ordinary Portland cement. Some of the findings are: (i) controlled incineration is required to produce RHA with structure that can result in structural concrete, (ii) the use of RHA resulted in increased water demand, (iii) up to 10% cement replacement with RHA will result in strength development comparable to the control specimens, and (iv) the use of RHA in concrete result in impervious RHA-concrete microstructure to agent of degradation like, sulphate attacks, chloride ingress, etc., as well as good shrinkage properties, and thus produce durable concrete when used. However, some areas such as the bending and shear responses (and allied properties) of reinforced concrete slabs and beams with RHA are presently not yet covered by researchers; they are therefore recommended for future investigation.

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.

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.

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.

Selecting a ventilation system for a certain building has always been considered as one of the critical problems for designers. Kingdom of Saudi Arabia (KSA) is characterized by a large area of significant climatic changes. In this research, five criteria are identified to compare and select one of the most popular ventilation systems, mechanical or natural. The identified criteria include Energy efficiency in buildings, Building function, Thermal comfort, the Maintenance cost of building, and Microclimatic conditions. The use of a mechanical system may be useful for achieving the building function and thermal comfort, while it seems to be more expensive. On the other hand, the natural ventilation system saves energy in the long run but it may not meet a comfort level for many users. Three regions which cover most of the climatic variations in the country are selected as a case study. A Ventilation Decision Making Model (VDMM), depends on the Analytic Hierarchy Process (AHP) as a multi-criteria analysis technique, is proposed and developed. For feeding data to the VDMM, field measures for indoor air temperature and relative humidity are conducted as well as applying an energy simulation model to predict indoor energy performance in the selected regions. Based on the results of VDMM application on the investigated case study, a decision to KSA construction market is introduced. The results absolutely support using the mechanical system in both Riyadh and Jeddah regions while utilizing the natural system in Abha region is more preferable. The VDMM is characterized by its flexibility, accepting more alternatives or criteria and its validity to be applied to other regions inside or outside KSA.