ALBERT

Description: Publication date: December 2017 Source: International Journal of Sustainable Built Environment, Volume 6, Issue 2

Description: Publication date: Available online 29 December 2017 Source: International Journal of Sustainable Built Environment Author(s): Yousef Al Horr, Ammar Elhoweris, Esam Elsarrag In an industrial climate where the reduction of carbon emissions is paramount to meeting industry standards for a sustainable future, the cement industry is looking for alternative and creative solutions to reducing its carbon footprint and energy consumption. The title thesis develops a novel process for the production of calcium sulfoaluminate (CSA) cement, a material produced in the Chinese construction industry for use as a rapid hardening binder for 5 decades; but now undergoing rapid change. The novelty of the proposed process lies partly in its source of sulfur. Typically provided by gypsum in conventional raw feeds, the novel process instead sequesters sulfur into the cement solids through the combustion of elemental sulfur. This combustion event, in turn, contributes towards the calorific value required to heat and maintain kiln temperatures by burning fossil fuel, e.g. natural gas. The combustion of sulfur also provides various added benefits. The resultant sulfur-containing atmosphere in the reaction system provides a protective environment which represses S volatilisation at the operating temperatures used for CSA production, ca 1200-1300°C. The novel process was developed with the intention for eventual commercial production in Doha, Qatar. The combustion of sulfur would be additionally beneficial due to the nation’s production of vast quantities of natural gas; elemental sulfur is a by-product of the Claus process, used for the desulfurisation of natural gas or sour crude. The proposed novel process would thereby utilise a waste product, i.e. sulfur, for the production of a low carbon cement product.

Description: Publication date: Available online 24 December 2017 Source: International Journal of Sustainable Built Environment Author(s): Alireza Salahi Moghadam, Ali Soltani, Bruno Parolin Every assessment of urban spatial structure requires determining the importance of activity centres. This paper gives an attempt to analyse the spatial and temporal changes experienced by major activity centres in the Sydney metropolitan area. The objectives of the research were first, to explore the role of main activity centres on the distribution of job opportunity across the metropolitan area, second to find out whether or not these key activity centres were influential in making the Sydney’s urban structure more poly-centric rather than being a mono-centric. It also estimates how accessible these activity centres are for the workforce and what their corresponding labour catchment areas are. Eleven activity centres were chosen based on the preliminary analysis of Sydney’s planning and development documents and exist evidences on living and working spots. A number of analysing techniques such as mapping of journeys to work in these centres, influence circles of centres, employment preference functions, and tabular data on the levels of employment were applied. The results of the analysis show that apart from the CBD, North Sydney, Parramatta and Inner City the remaining activity centres appear to exert slight impact on employment distribution across the metropolitan area. There does not seem to be evidence for a significant polycentric structure in Sydney metropolitan area in regarding with employment recruitment, seeking and retention.

Description: Publication date: Available online 16 December 2017 Source: International Journal of Sustainable Built Environment Author(s): Faiz Shaikh This paper presents the effect of silica fume (SF) on early-age and long-term mechanical properties of recycled aggregate concrete containing slag. In this study six series of mixes are considered. The first series is control concrete containing 100% ordinary Portland cement (OPC) and 100% natural aggregates. The second series is similar to the first series in every aspect except the natural coarse aggregate (NCA) which was partially replaced by 50% (by wt.) recycled coarse aggregate (RCA). The third series is also similar to the second series except the OPC which is partially replaced by 50% slag. The effects of 5, 10 and 15% (by wt.) SF on mechanical properties of concrete is evaluated in fourth, fifth and sixth series, respectively. Compressive strength, indirect tensile strength and modulus of elasticity of above concretes are measured at 3, 7, 28, 56 and 91 days. Results show that the addition of 50% slag significantly reduced the above mechanical properties of concrete containing 50% RCA at early age. Among three SF contents, the 10% SF improved the above mechanical properties of recycled aggregate concrete containing slag at early ages (3 and 7 days) as well as at 28 days. The addition of 10% SF also improved the 56 and 91 days compressive and tensile strengths of recycled aggregate concrete containing slag. It is also found that the long-term (56 and 91 days) compressive and tensile strengths of recycled aggregate concrete containing slag and 10% SF are even higher than the OPC concrete containing 50% RCA and control concrete, respectively. It is also observed that the slow pozzolanic reaction of slag contributed to the long-term compressive and tensile strengths of recycled aggregate concrete containing slag and 10% SF. Strong correlations of measured compressive strength with indirect tensile strength and elastic modulus of above environmentally friendly concretes are also established.

Description: Publication date: Available online 17 December 2017 Source: International Journal of Sustainable Built Environment Author(s): Moncef Krarti, Fedaa Ali, Alaa Alaidroos, Mahdi Houchati 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 2,500 MW in peak demand as well as over 5,400 kilo-ton per year in carbon emissions. In addition, over 4,000 jobs per year can be created when this large-scale energy retrofit program is implemented over 10-year period.

Description: Publication date: Available online 16 December 2017 Source: International Journal of Sustainable Built Environment Author(s): İbrahim Türkmen, Enes Ekinci, Fatih Kantarci, Talha Sarici During the last few years, an increasing interest has been appeared for earth as a building material. Earth-based materials have been studied because of energy efficiency and ecologically sustainability. The chromite deposites, 10% of the world reserves, are processed in Elazığ Ferrochrome Factory in Eastern of Turkey. Elazığ Ferrochrome slag (EFS) as a by-product of the factory is produced roughly 50.000 tons in a year. The disposal, removal and storage of this by-product is a serious problem. Therefore, the utilization of this waste material in building applications is very important. The aim of this work is to investigate effects of gypsum and EFS additives on mechanical and physical properties of unfired earth brick (UEB) materials in order to assess their potential advantages in building applications. The earth material was characterized by laboratory tests. Four different UEB samples were produced by using different compositions of earth, gypsum, EFS and straw fibers. Compressive strength, water absorption coefficient, drying shrinkage, ultrasonic pulse velocity (UPV) and density of the prepared UEB samples were determined. The experimental findings have showed that the usage of gypsum and EFS in stabilizing process of UEBs was advantageous.

Description: Publication date: Available online 16 December 2017 Source: International Journal of Sustainable Built Environment Author(s): Annina Takala Water supply and sanitation services are essential to human and environmental well-being. Globally one of the biggest challenges to sustainable development is lack of access to improved water supply and sanitation services. Yet it is less obvious what sustainable development means in countries with high coverage of these services. In this article sustainable development is explored from the perspective of Finnish water supply and sanitation services. The study consists of eight semi-structured interviews with water sector experts and their views are analysed in relation to literature. In this article sustainable development is understood as a learning process and dialogue of values. The interviewed water sector experts primarily perceive sustainable development from an environmental point of view, and treat it in a rationalistic and mechanistic manner. Challenges are tackled by technological fixes, such as improving energy and material efficiency. It is argued in this paper that this kind of approach undermines the complexity and dynamicity of sustainable development and can suppress learning. Sustainable development is mostly explored only from the perspective of water services, although some of the interviewees recognise their role for wider societal development. Interaction and dialogue between water sector experts and the community regarding sustainable development is lacking or skills to accomplish this interaction are inadequate.

Description: Publication date: Available online 14 December 2017 Source: International Journal of Sustainable Built Environment Author(s): Parvaiz A Bhat, Mifta ul Shafiq, Abaas A Mir, Pervez Ahmed The world has seen the development and growth of urban areas at a faster pace. The rapid urban growth and development have resulted in the increase in the share of India’s urban population from 79 million in 1961 that was about 17.92 percent of India’s total population to 388 million in 2011 that is 31.30 percent of India’s total population. This fast rate of increase in urban population is mainly due to large scale migration of people from rural and smaller towns to bigger cities in search of better employment opportunities and better quality of life. Urban sprawl has resulted in loss of productive agricultural lands, open green spaces and loss of surface water bodies. Hence, there is a dire need to study, understand and quantify the urban sprawl. In this study, an attempt has been made to monitor land use/land cover of part of Dehradun city over two periods of time i.e. from 2004 – 2014 for change detection analysis and to assess urban sprawl using IRS P-6 data and topographic sheets, in GIS environment for better decision making and sustainable urban growth.

Description: Publication date: Available online 16 December 2017 Source: International Journal of Sustainable Built Environment Author(s): Yousef Al horr, Mohammed Arif, Amit Kaushik, Ahmed Mazroei, Esam Elsarrag, Shashwat Mishra Purpose The purpose of the paper is to establish links between Indoor Environment Quality (IEQ) factors that affect occupant productivity and Global Sustainability Assessment System (GSAS) building rating system. The paper analyses the current state of GSAS using a desktop study, survey and brainstorming session organised in a workshop with GSAS Certified Green Professionals (CGP). Methodology/Design/approach The study was conducted in three steps. First, a comprehensive literature review was conducted to identify IEQ factors that influence occupant productivity in offices. The second step was a desktop analysis of current GSAS building rating system to identify criteria and submittals that may help to increase occupant productivity. It was followed by a facilitated workshop of GSAS CGPs that included a survey and a brainstorming session to highlight the current state of GSAS rated building performances on occupant productivity. The workshop was attended by 41 CGPs in Doha, Qatar. Findings The paper highlighted that GSAS needs to be updated to increase occupant productivity in GSAS rated buildings. A periodic post-occupancy survey in GSAS buildings should be mandated to ensure better occupant productivity. The paper also presented various methods to make GSAS rated buildings more occupant-friendly. Originality/Value This study is the first study to analyse green building guidelines in the context of occupant productivity, especially in Qatar.

Description: Publication date: Available online 15 December 2017 Source: International Journal of Sustainable Built Environment Author(s): M. Alwetaishi, M. Gadi, U.H. Issa 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.