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Through this research, we measure the direct tensile strength of three important southeast Australian heritage dimension stones and compare the results with published values. The three stones are Sydney Sandstone, Victorian Bluestone and South Australian Black Granite. This information is crucial for stone masons when they are selecting and cutting stone for construction projects, as they need to ensure that the stone they use and the repair will be strong enough to withstand the loads and stresses it will be subjected to in its final location. Results show that direct methods of testing provide tensile strengths that are 30–63% of the indirect methods. When the direct tension to compressive strength ratio is considered, results of 2–7% are calculated for these stones. This is significantly less than the typically assumed 10% for intact rock. Three masonry bonding agents have been selected to determine their capacity to re-bond the dimension stone. Highly variable results were achieved, with re-bonded tensile strengths ranging from 6% to 104% of the intact strength. This variability is most likely related to the heterogeneity of the stones and the surface preparations. Based on these outcomes, it is recommended that stone masons carefully consider the product that is used for restoration works and that test samples be prepared to confirm capacities. Direct tension testing has been completed on Sydney Sandstone, Victorian Bluestone and South Australian Black Granite dimension stones. Direct tension results have not been previously published for these stones. Direct methods of testing provide tensile strengths that are 30–63% of the indirect methods on these stone types. When the direct tension to unconfined compressive strength ratio is considered, results of 2–7% are returned for these stones. This is significantly less than the typically assumed 10%. The performance of bonding agents on each of the stones provides variable results suggesting that careful selection of products is required and, if possible, test samples be prepared to confirm bond capacities. [ABSTRACT FROM AUTHOR]

Overhead wiring structures (OWS) provide physical support to overhead electrical wires that power trains. They are typically spaced at 50 to 70 m. In a rail network, tens of thousands of these structures are required. Although they are simple structures, due to their numbers; design, construction and maintenance often involve large capital investments. Their reliability is also crucial to a safe operating rail network. This paper presents a review of OWS in Australia. Electrification of train services began in the 1910s, making some of the OWS over 100 years old. Descriptions in this article include their structural forms, design, construction, assessment and maintenance. It follows with a structural assessment carried out on a century-old riveted OWS built in the 1910s. This OWS was decommissioned in a recent railway renewal project which allowed the assessments to carry out. The assessment provides insights into hundreds of similar aged OWS still being used today. Assessments carried out consisted of tensile tests, corrosion depth measurements, radiographic imaging, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDX). Crevice corrosion is common in locations where moisture accumulated. Material properties were similar to modern-day Grade 250 steel with satisfactory ductility. Corrosion depths were less than those predicted. Samples of riveted connection showed no sign of deterioration within connected plates. This study may provide insights into structural design, construction and maintenance of similar structures in Australia and abroad. [ABSTRACT FROM AUTHOR]

This paper presents experimental and numerical investigations into the post-fire cross-section compressive behaviour and resistances of circular recycled aggregate concrete-filled stainless steel tube (RACFSST) stub columns. Twelve stub column specimens, fabricated from concretes with three recycled coarse aggregate replacement ratios (0%, 35% and 70%), were tested after exposure to the ISO-834 standard fire for 0 min (i.e. at ambient temperature), 15 min, 30 min and 45 min. The experimental investigation included heating and cooling of specimens, cylinder tests and post-fire tensile coupon tests and stub column tests. The test results, including load–end shortening curves, failure loads and failure modes, were fully reported and the initial compressive stiffnesses and confinement effect were discussed. The numerical investigation was subsequently conducted, where thermal and mechanical finite element models were developed and validated against the test results and then used to perform parametric studies to generate further numerical data. Given the absence of design codes for stainless steel–recycled aggregate concrete composite structures after exposure to fire, the relevant design rules for circular natural aggregate concrete-filled carbon steel tube stub columns at ambient temperature, as set out in the European code, Australia/New Zealand standard and American specification, were assessed, using post-fire material properties, for their applicability to circular RACFSST stub columns after exposure to fire, based on the test and numerical data. The assessment results generally revealed that the European code and the Australian/New Zealand standard led to an acceptable level of design accuracy and consistency, while the American specification resulted in rather conservative and scattered post-fire cross-section compression resistance predictions. • The compressive behaviour of circular RACFSST stub columns after exposure to fire is investigated. • Post-fire compression tests on twelve circular RACFSST stub column specimens are conducted. • The influences of heating durations and RCA replacement ratios are analysed. • Thermal and mechanical FE models are validated against test results and then used to conduct parametric studies. • The relevant design codes are assessed against the test and FE data. [ABSTRACT FROM AUTHOR]

In recent years, high strength steels (HSSs) with a minimum nominal yield stress of 460 MPa have been increasingly used in structural applications. An HSS may exhibit continuous or discontinuous yielding, depending on the chemical composition and manufacturing process and procedure. However, no criterion has been proposed in the literature to predict the occurrence of a yield plateau. Meanwhile, the ductility of HSSs is often limited, making it essential to predict their fracture for a safe design. However, existing stress-strain models used for HSSs cannot meet this need. To develop versatile stress-strain models for HSSs, 212 test curves are collected from open literature. In addition, four curves are obtained from tensile tests of two types of HSS produced in Australia (Bisalloy 80 and 400). By analysing the collected test data, a criterion is proposed to determine the occurrence of the yield plateau according to the yield stress of the steel and its carbon content. Two stress-strain models are then proposed for HSSs exhibiting continuous and discontinuous yielding, respectively. Moreover, predictions from the discontinuous model are also compared with the test data of conventional mild steel, proving that the model can also capture the stress-strain response of the conventional mild steel. Finally, the proposed models are used in the simulation of HSS coupons and beams, which proves the feasibility of the proposed HSS models for structural analysis. [Display omitted] • A criteria is proposed to predict the yield plateau occurrence of HSS. • Two stress-strain models are proposed for HSSs with or without a yield plateau. • The discontinuous yielding model can also be used for conventional mild steel. • The proposed models have been used in the simulation of HSS coupons and beams. [ABSTRACT FROM AUTHOR]

Cold-formed steel (CFS) claddings are increasingly used in bushfire prone areas in Australia due to their non-combustibility and are recommended in the Australian standard AS 3959 for the design of buildings in bushfire prone areas. Thus, good knowledge and understanding of their behaviour at elevated temperatures is important for the safe design of buildings. However, the elevated temperature mechanical properties of thin CFS cladding profiles have not been investigated. Hence, this research investigated the elevated temperature mechanical properties of high strength CFS cladding profiles through steady-state tensile coupon tests. More than 100 coupons, taken from the crests of three different cladding profiles with thicknesses of 0.42 mm and 0.48 mm, were tested to failure at predetermined elevated temperatures. The elevated temperature mechanical property results were compared with corresponding results from previous studies conducted on CFS sheets and sections, and the predictions obtained from the Australian CFS design standard. These comparisons showed that currently available equations can be used to determine the elevated temperature stress–strain curves and mechanical properties of CFS cladding profiles except for ultimate and fracture strains. Since no suitable equations are available for ultimate and fracture strains of CFS at elevated temperatures, new equations are proposed for CFS with varying thicknesses. • Conducted elevated temperature tensile coupon tests of three CFS cladding profiles. • Cold-forming has minor influence on the elevated temperature mechanical properties. • Current mechanical property reduction factor equations can be used for CFS cladding • Two-stage stress-strain model can predict the stress-strain curves of CFS cladding • Proposed new predictive equations for ultimate and fracture strains. [ABSTRACT FROM AUTHOR]

• MDT of aged railway masonry arch bridge for masonry characterisation. • Influence of number of bed joints in the core samples on the compression strength. • High strengths of aged masonry than expected. • Comparison of mechanical properties obtained from flat jack and masonry core testing. • Digital Image correlation (DIC) technique as an efficient method for damage visualization and measurement. This paper aims to assess the strength of a 100 + year old masonry arch bridges in Australia that are currently in operation and routinely subjected to train loadings. Towards this end, 45 cores of 150 mm diameter with varied lengths and joint configurations were drilled from a typical bridge and tested. Out of these samples, 30 were tested under direct compression and 15 were tested for tensile strength with varying bed joint angles. The samples for compression testing were regularised by developing high strength mortar capping whereas, the samples for tensile strength were tested according to Brazilian testing method commonly used for evaluating the splitting tensile strength of materials. The typical failure mode of masonry under compression was due to vertical cracking in bricks, spalling and cracking in perpend joints. The average compressive strength of masonry was determined as 10.6 MPa. Young's modulus was also determined with a magnitude of 11,048 MPa which is comparable to an in-situ flat jack test conducted on the similar bridges. The increased number of perpend joints in masonry cores decreased the masonry compressive strength. Splitting tests revealed the average tensile strength of 1.34 MPa. From the results it can be concluded that the aged masonry used in the arch bridge has a higher strength than previously thought of and that the bridge seems to be capable of sustaining the current train loads, as observed at site. [ABSTRACT FROM AUTHOR]

The paper presents a series of four-point bending tests investigating global buckling of cold-rolled aluminium alloy channel beam members. These types of sections have been commercially fabricated in Australia using a roll-forming process as distinct from the usual extrusion process. A total of twenty specimens of three commercially available channel sections with two thicknesses and various lengths were tested at the University of Sydney. Mechanical properties of aluminium alloy 5052 material were reported on the basis of tests of tensile and compression coupons cut longitudinally from both flat and corner parts of the cross-sections. Prior to the testing of beams, initial geometric imperfections of each specimen were measured using a laser scanning method. A dual-actuator test rig was specially designed to maintain the load vertically applied through the shear centre of the channel section throughout the test. Flexural-torsional and distortional buckling modes were observed including interaction of these modes. The paper also details finite element (FE) models developed using the commercial ABAQUS software package to simulate the behaviour and ultimate member buckling capacities of cold-rolled aluminium alloy channel beams. The FE models with the incorporation of measured properties and actual imperfections are verified against the experimental results indicating good agreements. The test results are then compared with the design strength predictions from current specifications. The calibrated model results are laying the foundation for undertaking parametric studies and proposing new design rules for the global and distortional buckling capacities of these types of cold-rolled aluminium alloy channel sections in the subsequent work. Unlabelled Image [ABSTRACT FROM AUTHOR]

This study estimates the geomechanical properties of coal of varied ply lithotypes and mudstone by using the experimental Short Impact Load Cell (SILC) test. SILC is an alternative laboratory test for measuring tensile strength, stiffness, and specific fracture energy (fracture toughness). Available coal data is rare for low rank sub-bituminous coals that are the target for coal seam gas stimulation and extraction in the Surat Basin, Australia. Tested specimens include mini-core and irregular particles. The results demonstrate geomechanical properties can be derived and used in the reservoir numerical modelling investigation. [ABSTRACT FROM AUTHOR]