This paper reports the results of a series of material performance tests undertaken to compare Chinese and Australian 500 MPa reinforcing steel. After providing some background to modern high strength reinforcing steel, this paper compares the chemical and mechanical requirements of the reinforcing steels in Chinese codes with those in Australian standards. The results of tensile strength and ductility tests are reported. From the requirements of the standards and the analysis of the test data, several conclusions are drawn. Small differences in the chemical composition cause some differences in mechanical properties. Because of the higher percentage of carbon, the tensile strength of Chinese reinforcing steel is generally higher than that of Australia’s normal ductility (N) reinforcing steel. The ductility of Australia’s normal ductility reinforcing steels is somewhat less than that of Chinese reinforcing steels, due to the higher percentages of the chemicals phosphorous and sulphur. However, because of the lower value of Ceq and carbon content, the weldability of Australian steel is higher than Chinese steel. By adding the trace elements V, Nb and Ti into the steels, the seismic ability of Chinese steels has been improved. Both Chinese and Australian reinforcing steels tested had adequate yield stress levels. In each country the test results indicated that the tested steel achieved the requirements of the applicable standard.

The choice of the best floor solution has always been a key issue in the design and construction of multi-storey timber buildings. Strict performance requirements such as effective acoustic separation of inter-tenancy floors, thermal mass, fi re resistance, limitation of deflection, resistance to vibrations and effective diaphragm action are very hard to comply with if only timber is used. The main purpose of this paper is to present the preliminary and some ongoing research in the short- and long-term carried out ainly at the University of Canterbury, New Zealand, for the realisation of a semi-prefabricated laminated veneer lumber (LVL)-concrete composite floor system in both the local and Australasian market. The paper discusses a novel semi-prefabricated LVL-concrete composite system where panels made from LVL joists and plywood flooring are prefabricated off-site. Once the panels are lifted onto the supports and connected side-by-side, a concrete topping is cast-insitu so as to form a continuous slab connecting all the panels. Composite action between the concrete topping and the panels is achieved using different types of connectors, such as various forms of notches cut from the LVL joists and reinforced with coach screws or toothed metal plates pressed in the LVL joists. After pointing out the advantages of the proposed system over traditional only-timber and only-concrete floor solutions, the paper describes push-out tests in the short-term on connections used in the LVL-concrete composite. Tests to failure of small LVL-concrete composite blocks (push-out tests) with different types and shapes of connection systems were performed at the University of Canterbury, New Zealand, and at the University of Technology Sydney, Australia. The results are parametrically evaluated and discussed in detail. The failure mechanism of the notched connection is highlighted together with the strength and stiffness values for each tested connection system. Subsequently, the four best connection systems were identified and used in beam specimens of 8–10 m in span. The experimental program on the beams is presented briefly in order to provide information of the different phases of the project.

This paper investigates and provides experimental evidence of the bond characteristics between carbon fibre reinforced polymer (CFRP) and steel plates under elevated temperature exposures. A series of tensile tests was carried out on CFRP/steel plates specimens joined together in double-lap shear joints and subjected to a range of environmental temperatures between 20 °C up to 60 °C, which would be usually encountered in civil infrastructure applications. High modulus (640 GPa) unidirectional carbon fibre plies were used in wet lay-up fabrication method to strengthen the composite matrix. Three different epoxy resins were used for the fabrication of the CFRP/steel specimens. The objective of the current experimental work is to determine the ultimate strength, failure patterns, elongation development, and lap-shear stress and slip variation under those exposures. This will help in enhancing the competency of using CFRP in retrofitting steel structures at high-temperature environments, usually experienced in civil construction applications.

"Erratum to “The use of characteristic strengths in masonry design”." Australian Journal of Structural Engineering, 8(1), p. 99

Review(s) of: K-E. Kurrer, The History of the Theory of Structures: From Arch Analysis to Computational Mechanics, Ernst & Sohn, Berlin, 2008, ISBN 9783433018385. Pagination on item given as p. 1-2, and relates to p. 73-74 of issue.

Risk assessment techniques need to be developed to quantify the safety hazards and economic losses posed by explosive blast loading, and the assessment of risk mitigation measures. The paper applies a probabilistic risk assessment to explosive blast damage caused by terrorist attacks to built infrastructure. Window glazing is adopted as a typical load-capacity system for detailed analysis. Fragility and blast reliability curves are developed for annealed and toughened glazing, for various threat scenarios comprising combinations of explosive charge weights and stand-off distances. Knowledge of the relative likelihood of these threat scenarios are then used to calculate probabilities of glass failure for a typical building facade. A life-cycle cost analysis is used to assess the sensitivity of the most cost-effective design solution for glazing to the attack probability.

Buildings and people working within the buildings are becoming increasingly vulnerable to terrorist attack. The use by terrorist groups of large vehicle bombs in areas accessed by the public is a matter of great concern. Government authorities worldwide are taking a closer look at the safety of infrastructure, energy supply, nuclear power plants and buildings. Structural engineers today need guidance on how to design structural systems to withstand various acts of terrorism and threats. This paper addresses the potential effects of a postulated bomb blast and identification of protective measures to mitigate risk. It briefly discusses background and definitions for explosive loads, general principles of blast loads and response prediction, and some recommendations for protective design of building structures.

Nowadays, a great number of heritage buildings are affected by structural defects. This paper presents the particular case of the Our Lady Cathedral of Tournai (World Heritage – UNESCO). According to historians and archeologists, the gothic choir of this building shows signs of weaknesses (problems affecting the flying-buttresses, the buttresses and the very slender pillars) since its erection. Over the centuries, several teams of engineers and architects have studied the problem, trying to understand the behaviour of the structure in order to propose a solution to preserve it. Unfortunately, using contemporary theories and calculations (graphostatic approach and limit analysis) these experts have not succeed in finding a convenient solution and the structural problems still exist today. A few years ago, a team from the Polytechnic Faculty of Mons began to study the building using Finite Element Models. From very simplified models, they began to understand the particular behaviour of the flying-buttresses. Then, by coupling their work with a team of archeologists and historians, they advanced their understanding of the building, making models more complicated and more precise. The analysis is based on “2D1/2” models taking into account the superstructure itself. All the materials involved in the study are assumed to be linear elastic. Some non linearities are introduced with a discrete iterative approach to simulate crack propagation. The results obtained confirm the result of preliminary studies but the observed pathologies are much more understood than with previous simplified models. By using FEM the behaviour of the building can be studied at each step of its life and the mistakes made by the engineers of the past can be better understood. Now, the effective behaviour of the flying-buttresses is better known and an effective solution for the future can be planned.

The behaviour of reinforced concrete one-way slabs subjected to horizontal translational end restraint is described in this paper. The presence of the end restraint induces compressive membrane action in the slab, increasing its strength and stiffness above that calculated using ßexural theory. The experimental component of this investigation involved the fabrication and testing of 16 one-way slabs, which were load tested under various boundary conditions. A very stiff reaction frame was used to impose the boundary conditions on the slabs. The results showed a significant increase in load-carrying capacity (up to 2.5 times greater) when the slabs were subjected to horizontal translational end restraint compared to simply supported slabs. This increase can be attributed to the presence of compressive membrane forces in the slabs. The results from these tests were compared to non-linear finite element models and a method of analysis developed by Rankin and Long.1 Good agreement with the experimental results was obtained using both finite element analysis and Rankin and Long’s method. Variables that affected the peak load, according to Rankin and Long’s method, were also investigated.

This paper utilises the strut and tie method, recommended in the AS3600–2001 concrete structures code¹ to develep a corbel design chart for 20 to 100MPa concrete. The method encompasses a trial and error procedure to determine the amount of tension reinforcement required in a corbel to resist the anticipated loading. Relevant design constraints from various major design codes are highlighted and a modified efficiency factor is used to enable the chart to be used for concrete strengths up to 100MPa. The results of recent research are used to ascertain the adequacy of the design charts developed. The chart provides a useful tool for designers by eliminating the need for an iterative design procedure, enabling the direct design of concrete corbels to take place.