'Smart repair' strategies using advanced metrology for enhanced structural health monitoring

Much of our current infrastructure, built of modern materials such as concrete, has or will require extensive repair, in service - often after even a relatively short period of its design life or to extend that life and reduce the costs on 'new build'. Currently an estimated ~600M is spent annually on the repair and maintenance of concrete infrastructure in the UK alone, a figure that is multiplied many times across the developed nations. Serviceability and enhanced whole life performance are critical to effective use and the long-term monitoring of such structures is invaluable to ensure full structural capability, to minimize risk to the public and give value for money. Further, there is a clear future for concrete infrastructure: the advancement of lightweight materials with a long service life is seen as essential to sustainable development, for example using highly durable lightweight, low energy concrete which can be used in a novel and pre-cast products and incorporating within it advanced monitoring systems. However, critical to achieving the maximum value from our infrastructure is a fuller understanding of the needs and challenges of allowing for better assessment of existing structures during their service lifetime as well as the creation of better structures for the future, using new materials. In both cases effective monitoring systems, installed or retrofitted and used to give reliable and informative data, having the confidence of the user community and industry, need to be developed and used widely. Thus monitoring and evaluation of the efficacy of repair strategies, as a key aspect of structural health monitoring, is the target of this proposal. This is made possible, uniquely in this project, by two factors coming together - the availability of a bridge where the damage conditions that have been applied since the bridge was moved to its present site will be well known and closely documented (as part of work done by NPL), as are the repair strategies that have been and will be applied to it. Addressing this in this project is the use of new, calibrated monitoring devices applied both during the repair procedure itself and subsequently, in both cases to allow the effects of the repair on the bridge to be monitored quantitatively and the work is thus very complementary to and adds value to research currently at NPL. Conventional SHM provides an assessment which allows the owners of large engineering assets to schedule maintenance more accurately, and can give an early warning of possible structural failure. The sort of system proposed in this project will provide early warning of potential problems and help in the better planning of maintenance and repair: the proposal herein will allow the repair strategies to be determined, monitored and evaluated. The overall aim is thus for better information to predict the likely potential for failure, the need for repair, the efficacy of the repair and thus the likely lifetime of a structure such as a bridge. This recognizes the wide industrial need for predictive systems that can monitor structures and inform the asset holder on its state of health, both in terms of its physical structure and chemical changes, where the type of structure could include bridges, buildings, power plant, aircraft, chemical plant etc. Even just considering the situation with bridges, a simple clear indication of the structure's health will provide substantial economic benefits since there are over 10,000 bridges worth more than 1M each in the UK alone - offering effective repair and thus cheaper maintenance and lower running costs would thus be of significant benefit.

A major aim of the work is to make a real impact on the industry and thus on the public at large. There are likely to be significant beneficiaries of the research outputs within the 'user communities', both immediately and in the longer term. For example, in the commercial private sector it is likely that the collaborating SME will be a beneficiary in being able to broaden its experience in the field and being able to bid to licence the exploitation of the 'know how' and explicitly the sensor systems which are developed in the course of the work. Other companies, such as sensor manufacturers will also be given the opportunity to bid for such a licence if necessary and this aspect will be led by the Technology Transfer Office (TTO) at City University. In addition, working with the Structural Health Industrial Advisory Group at NPL, which provides an industry-academic forum for the dissemination of work in the structural health monitoring field, other industries, academics and policy-makers would be exposed to the potential benefits from this research. As the work explicitly links to complementary a DIUS-funded research project at NPL, this will also enable the dissemination of the success of the work more widely. Further: - Are there any beneficiaries within the public sector, third sector or any others who might use the results to their advantage? Are there any beneficiaries within the wider public? In addition to the above, the success of the work is designed to have an impact on the wider public through the spread of good practice across the industry and the take up of the successful conclusions of the work by consultants and contractors to the building industry. This will be fostered by the dissemination of the conclusions of the work and the devices produced to industry via the licensing link to industry. The aim is for a safer environment for all through the minimization of building hazards though better maintenance and better repair strategies to the infrastructure that is all around, exploiting the success of the research and the methods developed. Thus the work has the potential to impact on the nation's wealth and wellbeing through a safer infrastructure and with its potential for impact outside the UK could impact positively on the economic competitiveness of the United Kingdom through export sales via the collaborating organizations. - How will they benefit from this research and what will be done to ensure that they have the opportunity to benefit from this research? The benefits to industry and the wider public will come from a wide dissemination of the results of the research. Following the advice of the University TTO and patent protection being sought, the work will be widely disseminated - to the collaborating industrial SME, to other industries via presentations to seek licensing agreements, to the relevant academic community via publications in the major Journals and at key Conferences and to the wider public via dissemination from City University Press Office - who have expertise in seeking to engage major newspapers and the broadcast media with the success of the work. The research group, led by the applicants, has an excellent record of engagement with beneficiaries of the research work, through having been awarded a number of grants and contracts from EPSRC, the EU and charities - to engage directly with outside organizations and to involve industry and end users in the work previously done. Details of the work and its impact (as discussed above) will be featured on the University website. In addition, opportunities will be taken via the University's membership of the Sensors KTN to disseminate the success of the work and promote wider links to industry and the user community. Thus overall it is anticipated that with take up by industry, the impact of a safer and better structural environment arising from the methods developed and exploited will be seen by the wider public.