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A simple test method to determine the in-plane shear properties of pultruded materials, where the mat reinforcement is of randomly oriented continuous fibres, is presented. Existing standard test methods have a number of weaknesses, but a number of them can be overcome by using the 10° off-axis tensile test method proposed by Chamis and Sinclair in 1976. Straight-sided specimens have unidirectional fibre reinforcement oriented at 10° to the direction of tensile load. Tension generates a biaxial in-plane stress state that, by employing stress and strain transformations, enables the shear modulus to be determined. The mean shear moduli of web material in four shapes, from 20 coupon tests in batches of five, were found to be consistent at 4·2–4·8 GPa. Given that 10° off-axis coupons are easy to prepare, with no technical difficulties, this non-standard method is recommended to characterise the in-plane shearing of pultruded materials having continuous-filament (or strand) mat reinforcement. [ABSTRACT FROM AUTHOR]

This paper presents an investigation on axially loaded polygonal-shaped steel-tube columns filled with high-strength concrete. The tubes had triangular, hexagonal and octagonal cross-sections, the concrete had a nominal concrete compressive cylinder strength of 100 MPa and the steel had a nominal yield strength of 285 MPa. For each tube cross-section, two identical specimens of concrete-filled tubes and one specimen of a hollow tube were examined. Load shortening, strain histories and failure modes were recorded and compared. Finite-element analysis with three different existing constitutive models of concrete were also developed and validated against the experimental results. The load-carrying capacities of the concrete-filled tubes were compared with the derived values from BS EN 1994-1-1:2004, ACI 318-11/AISC 360-16 and GB 50936-2014. The feasibility of current design standards for concrete-filled steel-tube columns of different cross-sections is discussed. [ABSTRACT FROM AUTHOR]

Advances in technologies have allowed manufacturers to produce steel plates and sections with strengths of 690 MPa and higher. The use of high-strength steel has the potential for significantly reducing the material costs and the self-weight of structures. High-strength steel hollow sections can be either welded from steel plates or cold-formed from coils. Tests on different built-up high-strength steel hollow sections have been conducted around the globe, including Australia, China, Japan and the USA. The commonly used box-sections were tested; the slenderness limits and member capacities against compression were also studied. To investigate the performance of cold-formed high-strength steel hollow sections, the authors initiated a research programme in Hong Kong, which included both experimental and numerical investigations on cold-formed high-strength steel hollow sections. The sections include square, rectangular and circular hollow sections. Based on the results, recommendations on section slenderness limits and expressions for determining member capacity are proposed in these studies. This paper summarises recent research on high-strength steel hollow sections and also addresses the design recommendations and limits in codes for both built-up and cold-formed high-strength steel hollow sections. [ABSTRACT FROM AUTHOR]

The behaviour of seismic-resistant buildings relies heavily upon the inclusion of energy dissipating devices. For concentrically-braced frames, this function is accomplished by diagonal bracing members whose performance depends upon both cross-sectional properties and global slenderness. Traditionally preferred rectangular hollow sections are susceptible to local buckling, particularly in cold-formed tubes, owing to the residual stresses from manufacture. This paper explores the response of hollow and concrete-filled circular tubes under cyclic axial loading. The uniformity of the circular cross-section provides superior structural efficiency over rectangular sections and can be further optimised by the inclusion of concrete infill. A series of experiments was conducted on filled and hollow specimens to assess the merit of the composite section. Comparisons were drawn between hot-finished and cold-formed sections to establish the influence of fabrication on member performance. Two specimen lengths were utilised to assess the influence of non-dimensional slenderness. Parameters such as ductility, energy dissipation, tensile strength and compressive resistance are presented and compared with design codes and empirically derived predictions. [ABSTRACT FROM AUTHOR]

An introduction is presented in which the editor discusses various reports within the issue on topics including a literature review on elastic modulus of recycled concrete aggregates, the use of neural networks to optimise the strength of mortar with carbon nanotubes (CNTs) and nanoclays, and the adaptive neuro-fuzzy inference system for improved analytical model for predicting the shear strength of reinforced-concrete beams.

An introduction to the journal is presented in which the editor discusses topics within the issue including investigations on timber arched suspension bridge, effectiveness of shallow-angle bent-up bars used in reinforced concrete construction and evaluation of the generalised beam theory.

An introduction is presented in which the editor discusses various reports in the issues on topics including flexibility matric of a timber composite beam, risk assessment on class 3 buildings in Great Britain and decision model for choosing steel and concrete forms for an office block.