Development of self-compacting concrete

Self-compacting concrete (SCC) can be defined as a fresh concrete which possesses superior flowability under maintained stability (i.e. no segregation) thus allowing self-compaction-that is, material consolidation without addition of energy. It was first developed in Japan in 1988 in order to achieve durable concrete structures by improving quality in the construction process. This was also partly in response to the reduction in the numbers of skilled workers available in the industry. This paper outlines a brief history of SCC from its origins in Japan to the development of the material throughout Europe. Research and development into SCC in the UK and Europe are discussed, together with a look at the future for the material in Europe and the rest of the world. Research and development of SCC is being conducted by private companies (mainly product development), by universities (mainly pure research into the material's properties), by national bodies and working groups (mainly the production of national guidelines and specifications) and at European level (Brite-EuRam and RILEM projects on test methods and the casting of SCC, respectively). Although SCC is not expected to ever completely replace conventionally vibrated concrete, the use of the material in both the precast and ready-mix markets in the UK, Europe and the rest of the world is expected to continue to increase as the experience and technology improves, the clients demand a higher-quality finished product and the availability of skilled labour continues to decrease

Understanding procurement methods in practice: an alternative perspective

The aim of this paper is to propose an agency-structure perspective on understanding how procurement methods are enacted in practice. It is argued that procurement methods manifest within a complex web of interconnections between various actors and the industrial structure. As an example, this paper focuses on the interrelations between the quangos' promotions of procurement initiatives and construction firms' responses to these initiatives. An understanding of such interrelations is achieved by integrating three sources of data regarding procurement developments. First, an analysis of the industry is considered as structural forces which influence procurement developments. This knowledge will be obtained through a literature review of the industry, including the overall economic conditions, the state of the industry itself, and the nature of construction demands. Second, the business path development of construction firms is regarded as responses to procurement initiatives. The method of case study will be applied to understand how construction firms' business path is related to procurement initiatives of time. Finally, a review of quango construction reports will be undertaken. Each report's key recommendations and impacts related to procurement initiatives will be identified. The three sources of data will then be plotted onto a timeline graph in order to form a more in-depth analysis. An assessment of the three sources of data at a chosen point/s for interconnections and causal relationships would then be undertaken. It is concluded that considering the interrelations between the three sources of data will offer a greater understanding of procurement methods in practice

Hybrid corrosion protection of a prestressed concrete bridge

The Kyle of Tongue Bridge in Sutherland, Northern Scotland opened in 1970, has an overall span of 184m of 18 approximately equal spans and carries a single lane dual carriageway. The bridge was repaired in 1989 due to chloride induced corrosion. However, inspections from 1999 onwards reported on-going corrosion and structural deterioration. A refurbishment contract was let in 2011 to extend the service life of the structure for a 20 year period by providing corrosion arrest and prevention. This paper describes how hybrid corrosion protection was used to offer protection to the prestressed concrete beams of the bridge. The results indicate that hybrid anodes provide an attractive alternative to other corrosion protection systems as they can be targeted to specific areas of need. They offer a temporary energising phase to arrest corrosion, followed by a permanent galvanic mode phase which is particularly beneficial for prestressed concrete structures in order to reduce the risk of hydrogen embrittlement

Nanotechnology in construction and demolition: What we know, what we don’t

Self-cleaning windows, very high strength concrete and thin, super-efficient insulation are just three examples of new building materials promised by nanotechnology, which manipulates matter at the atomic level. But for all their purported benefits, little is known about the risks posed by very small, engineered particles and fibres. Some long and very thin strands might act like asbestos if they are inhaled, for instance. To begin addressing this knowledge gap, the Institution of Occupational Safety and Health (IOSH) sponsored a research team at Loughborough University, led by Professor Alistair Gibb and Dr Wendy Jones, to investigate where these materials are used, how widespread this use is, what the potential risks are and how workers in construction and demolition might manage them. The executive summary of that report, released in January, is reproduced here with IOSH’s permission

Construction and repair with wet-process sprayed concrete and mortar

Purpose of the report The aim of the report is to provide practical guidance for designers, specifiers, contractors and clients on all aspects of low-volume wet-process sprayed mortars and concretes. It provides information on both new construction and small-scale repair and covers choice of application method, materials and mixes, specification, pumping and spraying, finishing, curing, testing and performance. The information is a combination of existing good practice and new knowledge acquired during a recently-completed three-year research project conducted at Loughborough University entitled ‘Wet Process Sprayed Concrete for Repair’. This was funded by both the UK Government (the EPSRC) and industry, namely Balvac Whitley Moran, Fibre Technology, Fosroc International, Gunform International Ltd and Putzmeister UK Ltd. This document concentrates on wet-process mortars and small aggregate concretes (< 8 mm) applied in thin layers (<100 mm) at low/medium output rates (< 5m3/hr), in some cases with mesh or fibre reinforcement. The report uses terminology standardised by the European Federation of National Associations of Specialist Repair Contractors (EFNARC), namely ‘sprayed concrete’, with mixes containing aggregate with a maximum size of 3-4 mm being classed as mortars and anything larger as concretes

Anticipating tomorrow: the future of the European construction industry

Executive summary: Exploring alternative feasible futures through engaging in a collaborative futures scenario development process has identified and prioritized a series of Key Actions for the ECI and its member organisations over the next 10 to 20 years. The very real challenges of how to most effectively address uncertain futures and rapidly changing working environments catalysed this work. The ECI Futures Task Force worked alongside the Big Ideas research team at Loughborough University to investigate and debate the range of issues and factors that might impact upon the European construction industry in the next couple of decades. This resulted in a set of four possible future scenarios for the industry and a series of five key characteristics for ECI’s preferred future for the industry. The work from the Task Force has identified two priority areas concerning the future of the European construction industry which are perceived to warrant further proactive intervention. Consequently the creation of two new Task Forces has been proposed – on ‘people’ and ‘collaboration’. These topics were chosen as being key areas in which ECI and its members could instigate proactive change and that would have a significant positive effect on the future of the European construction industry. The ‘collaboration’ topic also aligns closely with the vertical scenario axis. The horizontal scenario axis of energy scarcity and stabilised supply reflects more the wider background in which the construction industry operates, and which we therefore have less tangible control, and was therefore not chosen as an ECI Task Force. The focus of these proposed Task Forces would involve additional ECI members in further investigating future issues and taking a lead in implementing some of the Key Actions to help ECI and its members prepare for the future challenges ahead. It was agreed that the Industry Futures Task Force would produce the following outputs: • Final report highlighting methodology • ECI preferred future action Fact Sheet • Key actions from Fact Sheet • Recommendations for potential New Task Forces It was agreed that the Industry Futures Task Force would continue with its existing members plus the Chair persons of the newly created Task Forces, meeting twice per annum. It would provide a futures overview to ECI and the other Task Forces, engaging in horizon scanning, highlighting new issues as they emerge, and providing futures advice and expertise to ECI and the other Task Forces as they require