Strength and durability of composite concretes using municipal wastes

The influence of different types of polyethylene (PE) substitutions as partial aggregate replacement of micro-steel fiber reinforced self-consolidating concrete (SCC) incorporating incinerator fly ash was investigated. The study focuses on the workability and hardened properties including mechanical, permeability properties, sulfate resistance and microstructure. Regardless of the polyethylene type, PE substitutions slightly decreased the compressive and flexural strength of SSC initially, however, the difference was compensated at later ages. SEM analysis of the interfacial transition zone showed that there was chemical interaction between PE and the matrix. Although PE substitutions increased the permeable porosity and sorptivity, it significantly improved the sulfate resistance of SCC. The influence of PE shape and size on workability and strength was found to be more important than its type. When considering the disposal of PE wastes and saving embodied energy, consuming recycled PE as partial aggregate replacement was more advantageous over virgin PE aggregate replaced concrete

An Overview of Solid Waste Management and Plastic Recycling in Qatar

Municipal solid waste management (MSWM) constitutes one of the most crucial health and environmental problems facing authorities in the Arabian Gulf. Recent literature on current solid waste management (SWM) in Qatar has been reviewed in this paper, and a focused study has been carried out to provide a review on the total amount of municipal solid waste generated, stored, collected, disposed as well as the constituents of the waste. The analysis showed that Qatar produced around 2,000,000 tons of solid municipal waste annually, corresponding to a daily generation rate per capita of about 2. 5 kg. About 60% of MSW is organic material and about 300 kg is composed daily. Landfill and composting is considered the most appropriate waste disposal techniques in Qatar. Um-Al-Afai landfill has nearly 80% of MSW. Because of the increased migration in Qatar, there is a sharp rise in the volume and also in the variety of solid waste. It is important to alleviate societal concerns over the increased rate of resource consumption and waste production; thus, policy makers have encouraged recycling and reuse strategies to reduce the demand for raw materials and to decrease the quantity of waste going to landfill. An example of the benefit of mechanical recycling of plastics compared to land filling and composting was conducted by GaBi 4 life cycle analysis tool which showed the benefits to the global warming and human toxicity. Recycling is the favored solution for plastic waste management, because it has a lower environmental impact on the defined impact categories, from Global Warming Potential (GWP) and Human Toxicity Potentials (HTP) indicators.Acknowledgments This work has been supported by QSTP, Qatar Science and Technology Park. The authors also acknowledge the support provided by Qatar University for this work.Scopu

EIA and EMS integration : Not wasting the opportunity

Environmental tools such as environmental impact assessment (EIA) and environmental management systems (EMS) can be applied to ensure that major projects are constructed and operated using an approach that enables effective environmental protection. Previous research has shown that these tools are frequently applied in isolation at different stages of the project life cycle. The extent of EIA/EMS integration amongst nine of the biggest UK waste management companies was investigated through semi-structured interviews with environmental staff and thematic analysis of their responses. The research found that partial integration of EIA and EMS is widespread. Companies recognised a range of potential benefits to more closely integrating their processes such as system efficiencies, data availability and recognition from the regulator. However, significant barriers to further integration were identified in the form of cost, company structure and the size of the organisation. In a context where the regulation of the waste industry is increasingly aligned towards a risk-based approach, there is a new opportunity to use EIA outputs in an enhanced EMS. More generally, companies should seek to maintain continuity of personnel across the project life cycle and structure their environmental functions so that EIA and EMS staff can work more closely. This would help ensure that the greatest benefit is derived from both tools.Peer reviewe