Effects of layer orientation of CFRP strengthened steel hollow members

This paper reveals the effects of layer orientation on structural behaviour of three layers configured (LHL, HHL, LLH) CFRP strengthened circular hollow section (CHS) members subjected to bending. The beams were loaded to failure under four-point bending. The structural behaviour of the CFRP strengthened tubular steel beams with various layer orientations were presented in terms of failure load, stiffness, composite beam action and modes of failure. The LHL and LLH layers oriented strengthened beams perform slightly better than HHL layers oriented strengthened beams. The LHL and LLH layers oriented treated beams showed very similar structural behaviour.

Comparative durability study of CFRP strengthened tubular steel members under cold weather

In strengthening systems, the CFRP (Carbon Fibre Reinforced Polymer) materials typically have excellent resistance against environmental conditions; however, the performance of adhesives between CFRP and steel is generally affected by various environmental conditions such as marine environment, cold and hot weather. This paper presents the comparative durability study of CFRP strengthened tubular steel structures by using two different adhesives such as MBrace saturant and Araldite K630 under four-point bending. The program consisted of testing twelve CFRP strengthened specimens having treated with epoxy based adhesion promoter, untreated surface and one unstrengthened specimen and conditioned under cold weather for 3 and 6 months to determine the environmental durability. The beams were then loaded to failure in quasi-static manner under four-point bending. The structural responses of CFRP strengthened tubular steel beams were compared in terms of failure load, stiffness and modes of failure. The research findings show that the cold weather immersion had adversely affected the durability of CFRP strengthened steel members. Design factor is also proposed to address the short-terms durability performance under cold weather.

Extending building information models to construction specifications

This project examined the role that written specifications play in the building procurement process and the relationship that specifications should have with respect to the use of BIM within the construction industry. A three-part approach was developed to integrate specifications, product libraries and BIM. Typically handled by different disciplines within project teams, these provide the basis for a holistic approach to the development of building descriptions through the design process and into construction.

Emerging issues for road construction and maintenance – A futuristic view

In the coming decades the design, construction and maintenance of roads will face a range of new issues and as such will require a number of new approaches. In particular, road authorities will be required to consider and respond to a range of issues related to climate change, and associated extreme weather events, such as the extensive flooding in January 2011 in Queensland, Australia Figure 1). Coupled with diminishing access to road construction supplies (such as aggregate), water scarcity, and the potential for increases in oil and electricity prices, this range of challenges bear little resemblance to those previously faced. In Australia, state and federal authorities face further pressures given the variety of needs resulting from the country's geographical and population diversity, expansive road networks, road freight requirements and relatively small population base.

Who owns Superman? The Man of Steel fights trademark law

Who is Superman’s greatest threat? Evil genius Lex Luthor? General Zod from the Phantom Zone? The doppelganger Bizarro? Super-villain Brainiac? Kryptonite? Or is it intellectual property law?

Pull-through strength of high tensile steel cladding systems

The profiled steel roof and wall cladding systems in Australia are commonly made of very thin high tensile steels, and are crest-fixed with screw fasteners. A review of current literature and design standards indicated the need to improve the understanding of the behaviour of crest-fixed steel cladding systems under wind uplift/suction loading, in particular, the local failures. Therefore a detailed experimental study using a series of small scale tests and some two-span cladding tests was conducted to investigate the local pull-through and dimpling failures in the commonly used steel cladding systems. The applicability of the current design formulae for the pull-through strength of crest-fixed steel classing systems was investigated first. An improved design formula was then developed in terms of the thickness and ultimate tensile strenth of steel cladding material and diameter of screw head or washer. This paper presents the details of this investigation and its results. A review of current design and test methods is also included.

Structural identification of a laboratory-based steel through truss cantilevered bridge with suspended span using a layered genetic algorithm with patternsearch step (GAPS)

Structural identification (St-Id) can be considered as the process of updating a finite element (FE) model of a structural system to match the measured response of the structure. This paper presents the St-Id of a laboratory-based steel through-truss cantilevered bridge with suspended span. There are a total of 600 degrees of freedom (DOFs) in the superstructure plus additional DOFs in the substructure. The St-Id of the bridge model used the modal parameters from a preliminary modal test in the objective function of a global optimisation technique using a layered genetic algorithm with patternsearch step (GAPS). Each layer of the St-Id process involved grouping of the structural parameters into a number of updating parameters and running parallel optimisations. The number of updating parameters was increased at each layer of the process. In order to accelerate the optimisation and ensure improved diversity within the population, a patternsearch step was applied to the fittest individuals at the end of each generation of the GA. The GAPS process was able to replicate the mode shapes for the first two lateral sway modes and the first vertical bending mode to a high degree of accuracy and, to a lesser degree, the mode shape of the first lateral bending mode. The mode shape and frequency of the torsional mode did not match very well. The frequencies of the first lateral bending mode, the first longitudinal mode and the first vertical mode matched very well. The frequency of the first sway mode was lower and that of the second sway mode was higher than the true values, indicating a possible problem with the FE model. Improvements to the model and the St-Id process will be presented at the upcoming conference and compared to the results presented in this paper. These improvements will include the use of multiple FE models in a multi-layered, multi-solution, GAPS St-Id approach.

Effect of bond length on the behaviour of CFRP strengthened concrete-filled steel tubes under transverse impact

Concrete-filled steel tubular (CFST) columns have shown great potential as axial load carrying member and used widely in many mission critical infrastructures. However, attention is needed to strengthen these members where transverse impact force is expected to occur due to vehicle collisions. In this work, finite element (FE) model of carbon fibre reinforced polymer (CFRP) strengthened CFST columns are developed and the effect of CFRP bond length is investigated under transverse impact loading. Initially the numerical models have been validated by comparing impact test results from literature. The validated models are then used for detail parametric studies by varying the length of externally bonded CFRP composites. The parameters considered for this research are impact velocity, impact mass, CFRP modulus, adhesive type, and axial static loading. It has been observed that the effect of CFRP strengthening is consistent after an optimum effective bond length of CFRP wrapping. The effect of effective bond length has been studied for above parameters. The results show that, under combined axial static and transverse impact loads CFST columns can successfully prevent global buckling failure by strengthening only 34% of column length. Therefore, estimation of effective bond length is essential to utilise the CFRP composites cost effectively.

Reducing the environmental impact of road construction

The practice of road construction and maintenance is inherently lean and efficient; a result of the economic benefits that are gained by minimizing wasted resources. In this age of conservation and environmental management, the inbuilt sustainability of existing road construction practices is being developed and extended to produce variety of environmentally sustainable options. A new concept of a “sustainable road” has emerged through both academia and industry, and is defined to be a road that is: - constructed to reduce environmental impacts; - designed to optimise the alignment (vertical and horizontal including considerations of ecological constraints and operational use by vehicles); - resilient to future environmental and economic pressures (e.g. climate change and resource scarcity); - adaptable to changing uses including increased travel volumes, greater demand for public and active (cycling and walking) transport, and; - able to harvest the energy to power itself.

Sustainable construction trends in journal papers

Sustainable construction is gaining worldwide attention and has inspired research to identify and solve the problems involved in its implementation over a project lifecycle. While an impressive number of papers have been published on the topic to date, little has been done to review these papers to identify current research status or provide guidance for future research. This paper reviews existing sustainability papers in 12 internationally renowned construction journals. Based on a three-stage literature review, sustainability papers published in these journals from 2000 to 2012 are analyzed in terms of the annual number of papers published and the research interests involved. The number of sustainability-related papers in construction increases from 30 papers in 2000 to 127 papers in 2012, which shows an increasing trend in sustainability topics. A content analysis identifies seven major research interest in sustainability, including: (1) sustainable project management; (2) sustainability assessment/evaluation; (3) sustainable technology/innovation implementation; (4) sustainable building/infrastructure performance; (5) government policy on sustainability; (6) enterprise sustainability, and; (7) sustainability education. The results of this study provide a reference for scholars and academics to understand the current status of sustainability research in major construction journals.

An investigation into challenges facing distributed teams: Case of South Australian construction projects

There is increasing momentum within the construction industry to deploy distributed teams on projects, yet the major challenges that companies face for managing teams in distributed arrangements have yet to be explored in the construction context. Driven by such need, this study is intended to present an account of the major challenges encountered throughout the life cycle of offshore outsourcing arrangements within the South Australian construction industry. To this end, the study describes the observations made within the natural contexts of one construction project in terms of the challenges to the success of deploying distributed teams for outsourcing of works. Discussions remain in dialogue with relevant theories and the pertinent literature to explain the interpretations and lessons learned and to underpin the conclusions made. It is contended that this study contributes to the field by providing an illuminating insight into potential challenges facing distributed teams being implemented in outsourcing tasks in construction projects. Discussions also offer practical guidelines for construction project managers and assist them in dealing with potential challenges of offshore outsourcing through the lenses of distributed team working principles.

Improving the competence of construction management consultants to underpin sustainable construction in China

As a vital component of construction professional services (CPS), construction management consultancy is in nature knowledge-intensive and client-tailored. Although recent studies have acknowledged the increasing role of this subsector of CPS in the attainment of sustainable construction, little attention has been given to the education and training of its main body, namely construction management consultants (CMCs). This study investigated the competence and knowledge structure of CMCs by taking China as an example. Using the methods of interview and questionnaire survey, three key competences of CMCs and the underpinned knowledge structure were identified. The identified competences are personnel quality, onsite practical skills, and continuing professional learning. Underpinned these competences are the knowledge structure composed of a number of disciplines including construction cost planning and control, civil engineering and construction, engineering contract and law, and construction project management. The research findings lay a solid foundation for future studies to probe into the role of construction management consultants in the area of sustainable construction.

Market structure of international construction professional services: Evidences from top design firms

Construction professional service (CPS) in the international arena has been very competitive despite that the industry is proliferating at a high rate. To excel in international business, CPS firms have the importance of building overseas competition strategies on a proper understanding of the international CPS (I-CPS) market. However, subject to borderless trade, information technology–based networking, global outsourcing, and changing forms of procurement, the I-CPS market structure has become more covert, intricate, and unstraightforward than before. Through examining business competition among top international design firms, this study aims to identify the attributes of the I-CPS market structure from two perspectives—concentration and turnover. Data from Engineering News-Record over the period 2001–2011 were collected to calculate market concentration ratios and turnover indices. The results show that I-CPS competition is characterized by atomism, much turbulence with a steady increase in competition intensity, and the predominant role of new entrants and exiting firms in market turnovers. The combination of concentration and turnover is found useful to address the attributes of the I-CPS market structure, which favors I-CPS firms to formulate international competition strategies in due ways.

Education for sustainability in construction management curricula

In response to the call for sustainability education in construction courses, higher education institutions have started to incorporate sustainability components into their construction courses to some extent. This research aims to investigate sustainability embedded in construction management (CM) courses using the Queensland University of Technology as a case study. A content analysis of its CM course structure, unit aims, learning objectives and lecture materials is conducted to examine the sustainability elements incorporated into the CM curriculum. The results show that the course incorporates sustainability components into the existing course structure mainly through horizontal integration, embedding sustainability into general units rather than as an add-on subject. Additionally, the sustainability topics embedded in the course cover a comparatively broad and balanced range of sustainability categories, i.e. background knowledge, policies and regulations, environmental issues, social issues and economic issues as well as technology and innovation, although social sustainability aspects need to be further strengthened. This research addresses the need for urgency in the development of an effective sustainability education framework for construction courses. It is expected that the findings from this study will facilitate the improvement of sustainability education in construction courses generally.

Submarine record of volcanic island construction and collapse in the Lesser Antilles arc: First scientific drilling of submarine volcanic island landslides by IODP Expedition 340

IODP Expedition 340 successfully drilled a series of sites offshore Montserrat, Martinique and Dominica in the Lesser Antilles from March to April 2012. These are among the few drill sites gathered around volcanic islands, and the first scientific drilling of large and likely tsunamigenic volcanic island-arc landslide deposits. These cores provide evidence and tests of previous hypotheses for the composition and origin of those deposits. Sites U1394, U1399, and U1400 that penetrated landslide deposits recovered exclusively seafloor sediment, comprising mainly turbidites and hemipelagic deposits, and lacked debris avalanche deposits. This supports the concepts that i/ volcanic debris avalanches tend to stop at the slope break, and ii/ widespread and voluminous failures of preexisting low-gradient seafloor sediment can be triggered by initial emplacement of material from the volcano. Offshore Martinique (U1399 and 1400), the landslide deposits comprised blocks of parallel strata that were tilted or microfaulted, sometimes separated by intervals of homogenized sediment (intense shearing), while Site U1394 offshore Montserrat penetrated a flat-lying block of intact strata. The most likely mechanism for generating these large-scale seafloor sediment failures appears to be propagation of a decollement from proximal areas loaded and incised by a volcanic debris avalanche. These results have implications for the magnitude of tsunami generation. Under some conditions, volcanic island landslide deposits composed of mainly seafloor sediment will tend to form smaller magnitude tsunamis than equivalent volumes of subaerial block-rich mass flows rapidly entering water. Expedition 340 also successfully drilled sites to access the undisturbed record of eruption fallout layers intercalated with marine sediment which provide an outstanding high-resolution data set to analyze eruption and landslides cycles, improve understanding of magmatic evolution as well as offshore sedimentation processes.