Search results

Due to the high demand of concrete, significant volume of natural resources is required, including virgin aggregates. Many studies have shown that the production of concrete has one of the highest CO₂ levels. Although efforts are in place to recycle, enormous effects on landfill and the wider environment remain. Research has suggested the importance of reusing construction and demolition waste such as aggregate for use in recycled concrete. However, robust construction and demolition waste reduction strategies are required. There have been numerous researches on the use of recycled concrete and its management in the construction industry. This paper further consolidates this position.

This paper exhibits the barriers and benefits of using recycled aggregates for construction industry. This is achieved via reviewing the current construction and demolition waste reduction strategies used mainly in three countries: the UK, Australia and Japan. These countries were selected since they seemingly have similar construction industry and environment. Subsequently, evolving barriers and benefits of using recycled aggregates for construction industry are also reviewed and discussed. And to support such focus, robust construction and demolition waste reduction strategies will be advocated.

The findings are summarized as follows. The recycling construction and demolition waste could have a positive net benefit compared to the procurement and production of virgin aggregate materials with the same properties. This is not only financially beneficial but also environmentally viable, as fewer resources would be required to produce the same aggregate material. There are effective ways to achieve a high recycle rate target, as demonstrated by Japan. The implementation of a similar recycling process could be implemented globally to achieve a more effective recycle rate through the help of governments at all levels. By creating awareness about the financial and environmental benefits of using recycled aggregate products, large recycling companies can be also enticed to follow suit.

The findings from this paper can ultimately support the construction industry to further consolidate and advocate the use of recycled aggregates.

To achieve the research aim, this paper reviews some of the main sustainability factors of recycled aggregates (including coarse and fine aggregates) and provides comparison to virgin aggregates.

As a part of adaptive and complex system thinking, geographic information systems (GIS) are beneficial particularly for transportation projects, where uncertainty is frequent. Accordingly, this paper aims to examine the utilization of GIS in line with adaptive and complex system thinking, as the basis of the methodical formulation of perceived gaps within the integrated transportation planning (ITP) specifically for the mega transportation projects. Such a framework is undertaken, as the mega transportation projects although may seem straightforward, however, are problematic and require more consideration than the traditional triple bottom line factors. Using the Sydney Metro as the case study, the outcome demonstrates the significance of the fourth separate dimension of engineering into the aforementioned bottom-line factors.

The research examines the utilization of adaptive and complex system thinking, as the basis of the methodical formulation of perceived gaps within the ITP. The use of Sydney’s Metro project is a novel example of the proposed methodical formulation and its empirical assessment and provides a better understanding of the use of mapping and planning tools for mega transportation projects.

Aptly, using the developed conceptual framework, this research further validates the inclusion of a separate engineering dimension with the usual triple bottom line factors. Such inclusion is paramount in responding to the existing ITP gaps found within the current literature.

This research uses GIS and ITP process to support the aforementioned adaptive and complex system thinking. This, in turn, is used as the basis of a methodical formulation framework in dealing with mega rail transportation infrastructure. To support such a proposition, Sydney Metro is examined as the basis of a case study.

Through the significance matrix, this paper aims to investigate and explore the main sustainability factors of mega transportation infrastructure projects. Sydney’s Metro mega transportation infrastructure is used as a case study. Sydney’s Metro was selected because of its sustainability challenges faced because of the areas’ diverse ecological zones. Sydney’s Metro is thus examined as the basis of best practice for the determination of the sustainability factors of transportation infrastructures.

Using the significance matrix as a methodology, this research evaluates the environmental impact assessment and environmental assessment processes, to alleviate the problems of the mega transportation infrastructure.

This research found that a more comprehensive determination is needed to further analyse the sustainability factors of mega transportation infrastructures, use of a significance matrix would further assess the environmental complexities of mega transportation infrastructures and the sustainability factors of mega transportation infrastructures should include a nonlinear and asymmetrical scheme highlighting its components and carefully outlining its integration and consolidation.

Although there is concurrent research into sustainability factors of mega transportation, this paper undertakes a new methodology for such infrastructure. While the significance matrix is not a new concept, it has never been used specifically for mega transportation infrastructure. Subsequently, using the significance matrix as a methodology, this research undertakes such environmental analysis and assessment and thus produces a qualitative risk analysis matrix. The findings from this research will ultimately assist the key stakeholders of mega transportation infrastructures to better plan, monitor and support similar projects.

The purpose of this paper is to provide an overview of condition monitoring using artificial neural network (ANN) integration as a part of transportation infrastructure systems.

This paper will review the concept of ANNs and its core functions for the optimization (to manage the asset in such a way that the condition does not fall below an acceptable minimum condition) of transportation infrastructure systems, in particular, the maintenance processes. In doing so, a specific and factual example of performance and condition measurement for roads will be also instigated.

This paper demonstrated that ANN has many advantages if the problems cannot be solved by the clear algorithm. In addition, ANN has the ability to be instructed to handle large data set. There are various intelligent algorithms available and accordingly ANN is not a new concept. However, the ANN’s overall ability to solve complex and interchangeable system problems (such as one, which is found within the transportation infrastructure systems) is its core advantage.

Although condition monitoring using ANN integration has been researched extensively, this paper provides additional example of integrated ANN for transportation infrastructure systems.

This paper aims to trial a novel method of improving the performance of rail systems. Accordingly, an evaluation of rail system dynamics (SD) using discrete event simulation (DES) will be undertaken. Globally, cities and their transportation systems face ongoing challenges with many of these resulting from complicated rail SD. To evaluate these challenges, this study utilized DES as the basis of the analysis of Melbourne Metro Rail's SD. The transportation SD processes including efficiency and reliability were also developed.

Using DES, this research examines and determines the Melbourne Metro Rail's SD. Although the Melbourne Metro Rail is still in progress, the DES developed in this research examined the system requirements of functionality, performance and integration. As the basis of this examination, the Melbourne Metro Rail's optimization was simulated using the developed DES. As the basis of the experiment, a total of 50 trials were simulated. This included 25 samples for each of efficiency and reliability. The simulation not only scrutinized the SD but also underlined some of its shortfalls.

This study found that information and communication technology (ICT) was the pinnacle of system application. The DES development highlighted that both efficiency and reliability rates are the essential SD and thus fundamental for Melbourne Metro Rail system functionality. Specifically, the three elements of SD, capacity, continuity and integration are considered critical in improving the system functionality of Melbourne Metro Rail.

This particular mega rail infrastructure system was carefully analyzed, and subsequently, the DES was developed. However, since the DES is at its inception, the results are relatively limited without inclusive system calibration or validation process. Nonetheless, with some modifications, such as using different KPIs to evaluate additional systems variables and setting appropriate parameters to test the system reliability measures at different intensities, the developed DES can be modified to examine and evaluate other rail systems. However, if a broader system analysis is required, the DES model subsequently needs to be modified to specific system parameters.

Through evaluation of Melbourne's Metro Rail in the manner described above, this research has shown the developed DES is a useful platform to understand and evaluate system efficiency and reliability. Such an evaluation is considered important when implementing new transport systems, particularly when they are being integrated into existing networks.

Efficient rail networks are critical for modern cities and such systems, while inherently complex, aid local economies and societal cohesion through predictable and reliable movement of people. Through improved system functionality and greater efficiencies, plus improved passenger safety, security and comfort, the traveling public will benefit from the enhanced reliability of the transportation network that results from research as that provided in this paper.

This research paper is the first of its kind specifically focusing on the application of DES on the Melbourne Metro Rail System. The developed model aligns with the efficiency optimization framework, which is central to rail systems. The model shows the relationship between increased efficiency and optimizing system reliability. In comparison with more advanced mathematical modeling, the DES presented in this research provides robust, but yet rapid and uncomplicated system enhancements. These findings can better prepare rail professionals to adequately plan and devise appropriate system measures.

The aims and objectives of this research are to establish whether or not the transition into green building in high-rise construction is practical. This is after considering several perspectives including financial, economic, environmental, and social. This subsequently leads to an evaluation on whether or not the continuation with a standard conventional build of high-rise buildings remains to be the most feasible option. Such objectives, therefore, aim to allow for validation of how and why high-rise construction designs are impacted through green buildings effects.

Through six defined steps, the methodology commences with an introductory section of what it means to build green. This section is further broken down to evaluate what factors are involved in constructing a green building. Furthermore, the life cycle energy (LCE) is used as a framework to evaluate the knock-on effects of green buildings and subsequent high-rise construction design implications.

Through defining the ongoing relationship of green materials and sustainable design, various implications for high-rise constructions were discovered. First and foremost, it was determined that the LCE is the central consideration for any high-rise building design. In evaluating the LCE, and overall operating energy of the 50-year cycle of a building was carried out. As the results showed, the operating energy represents around 85% of the total energy that is consumed at the end of the 50 years cycle of the building. Precise LCE calculation can lead to a more efficient design for high-rise buildings. As a result, an increased understanding of the current status of green buildings within the construction industry is paramount. This understanding leads to a better insight into the contributing factors to green building in high-rise construction and the construction industry in general.

The potential contribution that can be gained from this research is the awareness that is raised in the research and development of green buildings in high-rise construction. This can be achieved by using certain materials such as new energy-efficient building materials, recycled materials and so on. This research will contribute to defining a new way of sustainable buildings, particularly for high-rise construction. The outcome of the research will be beneficial for practitioners such as design engineers and other related professions.

The purpose of this paper is to review the Fuzzy Markov development for assessing the structural integrity of buried transportation bridges. In doing so, the appropriateness of Fuzzy Markov will be assessed, leading to the subsequent model.

This research will utilize the Fuzzy Markov techniques as the conceptual framework. Such methodology is further supported via the utilization and evaluation of 30 buried transportation bridges using the developed Fuzzy Markov model.

Subsequently, through a developed Fuzzy Markov model, this research found that as the basis of structural resilience, specific matrices for age-dependent transition probability can be compiled using conditional survival probabilities in the various structural states; as the basis of structural integrity, specific environmental and economic schemes can also be established based on inspection intervals, intervention systems and failure phases; exact inspection and maintenance intervals can be scheduled to further prolong an asset’s life; and clear and early warning signs can also be formulated for immediate intervention when the structural integrity of the asset are indeed compromised.

The gap within the literature currently surrounds the limitation of computational analysis for some buried structures such as bridges. Specifically, to streamline such evaluation and regimes, a Fuzzy Markov is developed and reviewed.

The purpose of this paper is to evaluate the green building certification systems. In doing so, a validation process, using confirmatory factor analysis (CFA), was undertaken.

An extensive literature review was conducted to highlight the paramount aspects of green building certification systems. Then, using a grounded theory, key findings of the initial literature review were explored. This was necessary to form a broad theoretical framework. Finally, CFA was performed to evaluate various green building certification systems.

Initially, it was noted that accreditation process was the central key for effective building certification systems, particularly at the international level. Further, using CFA, it was also determined that to increase the sustainable performance of the green building certification, meeting the increasing expectation of the system user is paramount.

When evaluating the green building certification systems, it is recommended to focus on a specific aspect of the programmes holistically. This needs to be done particularly towards delivering a clear message to the stakeholders globally; doing so may alleviate the many challenges of green building certifications.

Currently, various green building certification systems have been developed for local purposes. This raises the question of the adaptability of these systems across varying climates and geography in differing regions. Using CFA, this research will examine various green building certification systems to evaluate their applicability at a global level.

In successfully meeting city and metropolitan growth, sustainable development is compulsory. Sustainability is a must-focus for any project, particularly for large and mega rail infrastructure. This paper aims to investigate to what degree social, environmental and economic factors influence the government when planning sustainable rail infrastructure projects. To respond to such a matter, this paper focuses on two Australian mega-rail projects: the South West Rail Link (SWRL) and the Mernda Rail Extension (MRE).

As the basis of an experimental evaluation framework strengths, weaknesses, opportunities and threats (SWOT) and factor analysis were used. These two methods were specifically selected as comparative tools for SWRL and SWRL projects, to measure their overall sustainability effect.

Using factor analysis, in the MRE, the factors of network capacity, accessibility, employment and urban planning were seen frequently throughout the case study. However, politics and economic growth had lower frequencies throughout this case study. This difference between the high-weighted factors is likely a key element that determined the SWRL to be more sustainable than the MRE. The SWOT analysis showed the strengths the MRE had over the SWRL such as resource use and waste management, and natural habitat preservation. These two analyses have shown that overall, calculating the sustainability levels of a project can be subjective, based on the conditions surrounding various analysis techniques.

This paper first introduces SWRL and MRE projects followed by a discussion about their overall sustainable development. Both projects go beyond the traditional megaprojects' goal of improving economic growth by developing and enhancing infrastructure. Globally, for such projects, sustainability measures are now considered alongside the goal of economic growth. Second, SWOT and factor analysis are undertaken to further evaluate the complexity of such projects. This includes their overall sustainable development vision alignment with environmental, economic and social factors.

Environmental impact assessment (EIA) for transport infrastructure should consider geological constraints, legislative regulations, public policy and other strategic considerations. These strategic considerations and constraints that are often seen as the most challenging issues facing transportation planners are critically reviewed. Subsequently, this study aims to evaluate the enviromnetal impacts of civil transport infrastructure.

Using a mixed-method approach, this study examines the EIA and environmental impact statement (EIS) dimensions of transportation infrastructure.

Through the development of the EIA and EIS policy framework for transport infrastructure, this paper found that to better enhance the EIA and to effectively calculate various indicator variables, a hybrid approach to the method, known as input–output analysis (IOA), needs to be adopted. Knowing that a feasible cost breakdown is usually available within projects, it can be concluded that it is plausible to add an input–output (I–O) model into an existing EIS to obtain results not only for on-site effects but also for off-site effects. Moreover, some of the benefits of implementing a hybrid IOA can significantly improve the completeness of any conventional EIS for a range of quantifiable indicators, improve the ability to rank alternative options and provide a valuable overview of indirect impacts to be used for streamlining the EIA audit. For these reasons, input–output techniques could be incorporated as optional elements into the EIA standards.

With input from the Australian Bureau of Statistics and national I–O tables of the industry sector, this research was able to determine that indirect effects within transport projects are not being considered for what they are worth. This enables us to answer key questions dealing with the effects of EIAs on the transportation sector. This, in turn, can assist with planning through the commissioning of such projects.

The I–O model introduced in this paper will ultimately lead to better incorporation of various environmental elements. The findings of the paper can thus assist transportation planners in better aligning environmental impacts with EIA. This, in turn, can result in improvements in the completeness of any conventional EIS, enhance the ability to rank alternative options and provide a valuable overview of indirect impacts to be used for streamlining the EIA audit.