The use of a portable lightweight deflectometer (LWD) for construction quality control or material investigation for earthworks and road construction is increasing around the world. LWD is reviewed as a field evaluation tool, the test variables and data quality are discussed, and the usefulness and limitations for a variety of earthwork and road assessment scenarios are described. A state-of-the-art reference document is provided for LWD users, consultants, material specifiers, contractors, and clients. Data from road foundations (subgrades, granular capping, and subbase) and fully constructed in-service (thinly surfaced) roads were reviewed to demonstrate the flexibility of the LWD and to show that its determination of stiffness modulus may differ from that of the conventional falling weight deflectometer to a varying extent. A series of laboratory investigations was undertaken to demonstrate the sensitivity to uniformity of plate-surface contact and the limitations in the interpretation of peak displacement from the device. A good understanding of the device workings and careful specification of the test variables are required both to analyze the data correctly and to permit comparison between data sets. It is concluded that the device is a useful and versatile field quality control and pavement investigation tool if an understanding of the device issues is considered by data users.

Lime stabilisation is a versatile technique applied during earthworks operations. Modern soil recycling units are much more efficient at pulverising fill material and intermixing the added binder/water than machinery available 20 years ago. While supplier innovation adds flexibility to the site working method, specifications have not been sufficiently updated to permit optimal application. This review paper details the physico-chemical changes instigated through the lime–clay soil reaction, updating previous reviews. It aims to assist scientific debate, current practitioners and future specification changes. For example, the application of the minimum 24 h mellowing periods (mandatory to UK specifications) with high reactivity, quicklime powders is concluded to cause increased air voids in the compacted fill. Increased air voids are associated with reduced long-term strength and potential volume change from water ingress, which is of particular concern for sulfate swelling. Shorter mellowing periods and/or use of hydrated lime may lesson this issue; however, a ‘one size fits all' approach is discouraged in preference to site-specific methodologies refined to suit the fill material and project requirements. The discussion also summarises working methods which may lower the risk of sulfate swell and defines areas requiring further practical research.

Artificial sport surfaces, for team outdoor sports, are growing in number in many sports including soccer (association football), rugby, hockey, and football (American and Australian). The science of their behaviour has, it is argued, been under-researched in comparison to the development of artificial turf products and also the development of many of the sports with respect to athleticism and advances in equipment such as footwear. This paper reviews artificial turf design requirements and behavioural aspects to develop the science, and draws from a range of up-to-date literature to identify the key principles of behaviour and gaps in knowledge. The relationship between the material types used in the substrate support and surface system (comprising some form of shockpad and turf, the turf infilled or unfilled) behaviour is demonstrated in regard to the key performance factors of player–surface interaction – for both impact and traction. The data demonstrate the relatively complex behaviour of surface systems, and highlight the pitfalls of current simple mechanical tests in relation to human loading. Degradation and the role of maintenance to sustain long-term performance are issues also highlighted and discussed. Surface safety is discussed through a short review of studies related to injury risk, albeit most were associated with the contrast between natural turf and artificial turf; however, there is clearly more research required in injury surveillance to include aspects of objective surface measurement. This paper additionally provides the reader with a state-of-the-knowledge review of where current thinking is now, and where future research is considered to be of merit, in developing sport surface science.

To introduce a performance specification, pavement foundations must be designed using analytical methods incorporating the laboratory measured parameters of resilient elastic modulus and resistance to permanent deformation of the subgrade and foundation materials. This paper presents results from a program of repeated load triaxial tests performed on a range of fine-grained subgrades prepared in a number of states to evaluate these parameters for various design conditions. The results highlight several difficulties in measuring small strains on “undisturbed” soils over a large strain range and in predicting and modeling long-term behavior. However, testing at higher strains has shown that the deviator stress at which the cumulative permanent deformation starts to increase significantly, termed the “threshold stress,” approximates to 50% of the deviator stress at failure. In addition, the resilient modulus of the soils is shown to approach a low asymptotic value at higher deviator stress. Comparison betwee...

Sustainable construction and supply chain management (SCM) have, in recent years, become two of the most important performance-related issues within the construction industry. To achieve corporate sustainability within any organisation, it is essential that sustainability issues are addressed throughout the organisation's whole supply chain, a process referred to as sustainable supply chain management (SSCM). The implementation of SCM and sustainability is, however, an extremely complex undertaking. Through an extensive literature review and detailed interviews, this research has identified the conditions and strategies for achieving SSCM within construction organisations. The research also investigated the meaning, barriers and enablers, issues, tools and techniques for achieving successful SCM and SSCM. The study was based on the perspectives of senior managers of exemplar organisations with a proven track record in sustainability and SCM. It has been possible to identify best practice from which other organisations can learn, thus supporting the industry in the move towards more sustainable construction practices.

During sports movements the cleats (also termed studs) penetrate and interlock with the playing surface generating traction forces. The ability to generate traction between a player's footwear and a sporting surface is a crucial factor influencing the player's performance as well as safety from lower limb injury. The traction produced for a given shoe–surface combination is dependent on a number of interacting factors operating at the interface, including the sport movement, the surface system composition, the footwear design and environmental conditions. Prediction and understanding of the mechanism providing traction has remained elusive. This paper presents experimental laboratory and field-based research conducted to assess the physical properties of third generation infilled synthetic turf surface components and the system's influence on the resulting measured rotational traction behaviour. Element testing of the crumb rubber infill was carried out to determine compressibility and shear strength. Systems were then constructed in the laboratory, altering aspects of carpet type, infill mass and density. The current industry standard equipment used to measure rotational traction in accordance with performance limits in soccer (i.e. FIFA) was utilized and also adapted to evaluate its suitability as a method for assessing rotational traction behaviour of synthetic turf surface systems. The results show the net bulk density of the infill layer can be a key controlling factor for the traction produced by the surface system as a whole. The net bulk density derived for the infill is shown to be dependent on a number of contributing factors, including the carpet type, infill size distribution, thickness of the infill layer, the level of compaction and the subsequent loading applied to the infill during testing. The stud configuration used was also shown to be a slight factor in system behaviour; however, the greatest effect on peak rotational traction resulted from changing the static normal force applied (i.e. static weight applied to the test device during a test).