For more than two decades, construction industry leaders have made attempts to attract more women into professional roles to ease skills shortages and diversify the workforce. However, the number of women working in the industry has not improved significantly. This paper reviews previous literature on gender diversity in the construction industry and disseminates findings from a survey which investigated whether there are significant differences in self-perception between men and women in construction consultancies operating in the United Kingdom (UK). The survey questionnaire was completed by 60 men and 57 women. Analysis of the result confirmed that women tend to follow 'zig-zag' career development paths and that 'global self-worth' of women over the age of 40 is the lowest among all ages. However, little variation was found on initiatives to improve retention of women in construction consultancies. The results reveal that both men and women regarded 'improved flexible working-arrangements', 'transparent promotion criteria', 'return to work training', 'outreach programmes to schools' as the most crucial initiatives to retain women. This reinforces the call for organizations to introduce innovative strategic plan to change the masculine culture of the construction profession and to modernise working practice away from the existing rather outdated traditional structure.

The safe disposal of waste tyres has been seen as having a negative impact on the environment. To mitigate this impact, the components of waste tyres can be used in the production of green concrete. This study explores the effects of the curing and drying regime on the mechanical properties and permeation characteristics of concrete containing both crumbed rubber and steel fibres that are removed from waste tyres. Five concrete mixes were designed and concrete cubes, cylinders, and prisms were cast using waste tyres extracts. Crumb rubber was treated by submersion in sodium hydroxide and then used to partially replace 10% and 30% of fine aggregates in the concrete mix. Extracted steel fibres were added at the rate of 1% and 2% per volume of each mix. Compressive, indirect splitting tensile as well as flexural strengths were conducted after normal curing while observing several drying conditions. Additionally, air permeability was assessed using a portable apparatus which was developed to assess permeability easily. For the concrete test specimens containing 10% partial replacement of fine aggregate by crumb rubber and 1% steel fibres, it was discovered that the splitting tensile strength and flexural strength were higher than that of the control mix by 21% and 22.6%, respectively. For specimens, that included the 10% crumb rubber and 1% steel fibres, when exposed to oven drying at 105°C for 12 hours, the compressive strength results increased by 17% compared to the control specimens exposed to the same conditions. Unlike the compressive strength results, the splitting tensile and flexural strength results decreased after exposing the specimens to elevated temperature. The addition of crumb rubber and steel fibres as a partial fine aggregate replacement resulted in increasing the air permeability of the concrete to different degrees depending on the percentages used. The oven drying curing regime improved the permeability by reducing it in specimens containing the 10% crumb rubber and 1% steel fibres as indicated by increasing their permeability time index by 15% when compared to air-dried specimens. Using waste tyre extracts as a partial replacement of concrete fine aggregate can be recommended for both indoor and outdoor applications. This study showed that this was a viable, economic and environmentally friendly method for reducing carbon footprint.

Circuits of mutually supported elements (MSEs) can produce novel 3-dimensional spatial structures. In the creation of a circuit, the basic concept is that the primary members rely on each other for support. These novel structural arrangements may give rise to complexity in the configuration geometry and structural behaviour due to the creation of an eccentricity between elements. An experimental programme was designed to aid understanding of the primary behaviour of structures composed of MSEs. This investigation concentrated on the structural performance, under applied static loading, of a dodecahedric MSE space structure. The main objectives of the experimental investigation were to confirm behaviour as being linear elastic within a predermined appied load range, to understand the distribution of stress and the displacements of the structural elements, later to be compared with that predicted by numerical modelling. Displacements of closed MSE circuits with different spatial orientations were considered. Differences in the recorded strains were also considered. The experiment highlighted the difficulties associated with monitoring MSE circuits, particularly support stiffness and displacements of circuits with arbitrary 3-dimensional spatial orientations. The recorded strains were complex in nature in as far as they included the effects of axial forces, bi-axial bending, shear and torsion. It was found that the maximum applied load did not cause yield of the material according to the von Mises ductile material failure criterion.

Novel architectural forms can be created by connecting reciprocal frame (RF) and mutually supported elements (MSE) circuits together. These networks produce interesting architectural and engineering opportunities and challenges. The opportunities include the creation of roof and standalone structures that have distinctive architectural expression. The challenges include the determination of the often-complex configuration geometry between the elements and their connection system. A key feature of sloping RF and MSE geometry is that at the joint locations the element's centroidal axes generally do not coincide. An eccentricity at these positions has therefore to be incorporated within the connection system. This has a direct impact on element sizing, connection design, fabrication and erection sequences. RF and MSE spatial structure networks give rise to complex structural behaviour. Element-to-element connection eccentricity orientation is a controlling key feature in the determination of how the forces, moments and stresses are distributed between MSEs. The orientation of the eccentricity can be random or aligned to produce a vertical intersection distance as generally used in RF construction. The eccentricity derived from the common perpendicular to the centroidal axes is more commonly used in MSE circuit assembly. This paper considers the various methods used to connect RF and MSE networks and discusses their impact and comparative design advantages and disadvantages.

Highlights• PEG 400 admixture was used in concrete mixes produced for hot weather conditions • Dry materials, mixing water and curing temperatures simulated hot weather • Properties of PEG samples were found to be superior to the control concrete • Results cannot to attributed only to prevention of pore water escape by PEG 400 • A proposal was made to explain the results based on information from the literature ABSTRACT Hot climates prevail in many regions of the globe. The average summer temperature of hot arid areas is in the range of 40-50°C with temperatures exceeding these values under direct solar radiation. Curing concrete in these regions may be challenging due to limited availability of suitable water for curing and/or rapid loss of curing water by evaporation. For many years self-curing admixtures were recommended as an alternative to water curing, however, limited studies have been conducted on their performance in hot weather conditions. In this investigation, the effects of a hot climate on the fresh and hardened properties of self-curing (SC) concrete and normal conventional concrete (NC) in hot weather were studied. A watersoluble polymer self-curing agent, polyethylene glycol (PEG 400), was added to the SC mixes. The testing parameters were concrete dry materials (25 or 50 O C) and/or mix water temperatures (5, 20 or 35 O C) at the time of mixing. NC samples were continuously water cured at 25 or 50 O C, whereas the SC ones were air cured at the same temperatures. The tested properties were workability, compressive strength, splitting tensile strength, and flexural strength. It was found that SC outperformed NC under varying conditions. The results could not be simply attributed to the retention of mix water by the self-curing admixture. A more comprehensive explanation for the observations is proposed.