International Journal of Sustainable Built Environment最新文献

The use of geosynthetic in soil and coastal engineering is increasing and improving due to improvements in its engineering properties and fabrication techniques. While some geosynthetic coastal structures have attained advanced stage in terms of applications and efficiency, others still lack well-structured design formulas and specifications on a sound scientific basis, hence continued experimental works for the better understanding of the hydraulic performance, stability and modes of failure of these structures. Coastal areas are dynamic with unique geomechanical feature such as soil instability, which in any case, may affect the overall performance of coastal defence structures constructed on soft soil or weak foundation. This paper reviews the developments and applications of geosynthetics in soil stabilization and protection of coastal areas with emphasis on shoreline protection. Relevant empirical research data are presented as well as the present and likely future challenges in the use of geosynthetics in soil stabilization and coastal defence structures.

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).

An attempt has been made to study the subsurface groundwater discharge (SGD) in the coastal Cuddalore region of south east India. Measurement for Radon, water level, Electrical Conductivity (EC) and pH in surface water for a total of twenty hours by hourly interval has been attempted and further correlated with tidal values calculated by WX Tide 32 software. The SGD measurements were made by using a modified seepage meter. The study reveals a match with water level variation and tide with minor variation due to influx of surface water. Saline discharges, fresh groundwater discharges and surface water mixing processes were identified along the coast. Lower SGD (37.24–79.16 cm/day) was observed during fresh groundwater discharge.

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.