Whilst looking through my records in preparation of writing this editorial, I came to realise that this is the 4th editorial that I have written for the Structures and Buildings in the last couple of years. Much like the previous editorials, this issue is full of high quality research, presented with both researchers and end-users in mind, and includes excellent images, data and analysis. For each editorial that I have been invited to write, I have been delighted to see such a variety of topics covered, from a diverse range of backgrounds, thus highlighting the growing ‘internationalism’ of the journal!
In this issue, there are 5 papers in total, with 4 being focused on new developments for concrete structures, and one focussed on steel structural applications. For this reason, I decided to place the steel paper first in the running order. This paper has been prepared by researchers from the International Institute of Earthquake Engineering and Seismology in Tehran, Iran (Arjmandzadeh and Moghadam, 2022). It is concerned with the provision of lateral restraint in steel structures through the use of unstiffened steel plate shear walls (SPSWs). These inherently offer great stiffness and ductility and are desirable for applications that require self-centring to reduce residual drift under earthquake load. The work presents details of numerical simulations based on the strip model published by the American Institute of Steel Construction. It is identified that the compression resistance of the shear wall strips, and ensuring that there is realistic pinching behaviour and energy dissipation of the bolts in post-tensioned connections are key aspects for accurately depicting the behaviour, developing a reliable simulation of a self-centring frames with SPSWs.
The second paper, presented by researchers from Babol Noshirvani University of Technology in Babol, Iran, studies the bond relationship between glass fibre reinforced polymer reinforcing bars in both normal strength and high strength concrete (Bahnamiri et al., 2022). It is stated that existing bond models are not effective for these types of rebars. Existing data from bond tests was obtained, and a non-linear least-squares fitting method was used to propose simple models to represent the bond in an accurate way.
The third paper also looks at fibre reinforced polymer bars but, in this case, made from basalt fibre reinforced polymer (BFRP)–and the paper focusses on BFRP tubular columns containing geopolymer concrete. It is presented by researchers from the University of Wollongong, Australia, and the Hong Kong Polytechnic University, Hong Kong (Hadi et al., 2022). The paper includes the details and discussion on an experimental investigation which was carried out on a novel type of concrete-filled tubular column, which uses geopolymer concrete for the infill, and BFRP reinforcing bars and BFRP outer tube. The geopolymer concrete was used in place of ordinary Portland cement concrete and the BFRP was used in place of steel to overcome corrosion challenges. It is shown that the specimens with geopolymer concrete were more ductile compared to those with Portland cement concrete. It was also shown that the presence of load eccentricity in the columns resulted in ductility enhancement for the BFRP-containing specimensand the opposite effect for steel-reinforced specimens.
The fourth paper is written by researchers at Alexandria University in Egypt (Shoukry et al., 2022). The paper provides excellent details and discussion on a series of experiments that were conducted on ten simply supported slabs subjected to an increasing concentrated load at the slabs’ centre. The main studied variables were concrete strength (56 and 123 N/mm2), fibre content (0, 1, 2, and 3%), fibre shape (end-hooked or corrugated), fibre size with the same aspect ratio, fibre type and material (steel, polypropylene or fibreglass). Therefore, a large number of variables were examined, covering a wide range of potential applications and making this work very relevant to various structural designs. The test results indicated the efficiency of using steel fibres in ultra-high-performance concrete slabs to enhance their punching shear strength, which is a positive result for this construction form.
Finally, and by no means least, this issue contains a very interesting paper on the behaviour of concrete columns with high-performance concrete jackets and polymer wraps presented by researchers from University of Wollongong, Australia (Algburi et al., 2022). The paper includes cross-sectional analyses of circular and square reinforced concrete columns strengthened with reactive powder concrete jacketing and fibre-reinforced polymer wrapping, employing the stress block method to determine the theoretical axial load–bending moment interactions of the columns. These were then compared with experimental results and found to be in very good agreement.
I very much hope that all readers of Structures and Buildings will enjoy reading these papers, and will take value from the contents in their own applications. It is clear that although there are many new materials, and novel product forms, the structural engineering community is still also producing excellent fundamental research for a wide range of practical applications. As always, comments and discussions from the readers of Structures and Buildings are encouraged and will be welcomed.
