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.

Building stone has a finite life that can be drastically curtailed when it is placed in the often-aggressive environments experienced in today's urban settings - yet stone masonry is still widely recognized as an adaptable and sustainable construction material, with a low carbon signature, and as a repository of much of the world's tangible cultural heritage. Arising from this, it is essential that the choice of new and replacement stone and the conservation of decaying stone is underpinned by a detailed knowledge of how different stone types decay in specific environments and what factors trigger decay and control its rate once it is initiated. Data are limited from the wide range of stone types seen in structures existing today - the performance characteristics of only a limited number of comparatively durable stones are known and these are largely resistant to physical damage and decay is driven primarily by dissolution. The rate of solution of stones is influenced by factors such as rainfall amount, timing, atmospheric conditions and chemistry and thus, with knowledge of micro-environmental conditions in and around the building stone, decay rates are largely predictable from short-term observation. Despite rather advanced non-destructive methods currently used for assessing the deterioration process and their rates, the fate and extent of inner contamination of building materials remains largely unaccounted for by such methods. Therefore qualitative online health monitoring of these building materials using embedded sensors is essential, not only from the standpoint of economic planning and maintenance, but also on cultural, technical and scientific grounds. Novel sensor systems designed specifically for use in buildings constructed from stone can provide the data that conservators need which enable them to understand better the complex processes that are on-going and to model better and thus plan repair and maintenance procedures in a cost efficient and timely way. This work builds upon several previous EPSRC grants into both fibre optic sensor systems, civil structural monitoring and heritage stonework. However in particular this follow on application builds upon the successful technical achievements of a grant focusing on the test, evaluation and design of a suite of new sensor systems for stonework monitoring for both moisture and chloride transport. The work enabled a more detailed evaluation of the decay processes and the beginning of a better understanding of several key applications-focused issues from that grant funded. Recognizing that the Follow-on Fund is concerned with development towards an identified commercial opportunity, this project can be summarized as the development, commercialization and marketing of fibre optic sensor systems for monitoring ingress of moisture and moisture-borne salts in the context of structural monitoring and decay prevention of stonework, both historic and modern. Through carefully considered technical and commercial plans, it is intended to refine the sensors for the specific monitoring environments of stone masonry strucures and develop probes which can be used in stonework in a minimal invasive manner. The commercial feasibility will be established through in situ evaluation, market testing and working closely with an SME with specialised knowledge in monitoring the built environment.

Much of our current infrastructure, built of modern materials such as concrete, has required extensive repair after being in service for even a relatively short period of its design life. Currently ~600M pa is spent annually on the repair and maintenance of concrete infrastructure the UK alone, a figure that is multiplied many times across the developed nations. Serviceability and whole life performance is critical to effective use and the long-term monitoring of such structures is invaluable to ensure full structural capability and to minimize risk to the public and give value for money. For example, the advancement of lightweight, durable materials is seen as essential to future sustainable development, using highly durable lightweight, low energy concrete which can be used in a novel flexible concrete arch and other pre-cast products, incorporating within it advanced monitoring systems. However, in order to understand more fully the needs and challenges of creating better structures for the future using such materials (and allowing for better assessment of existing structures during their service lifetime) effective monitoring systems that can be installed and used to give reliable and informative data, having the confidence of industry need to be developed and used widely. Thus this project has been designed as a short, 12-month truly interdisciplinary study, to cross compare the issues surrounding the installation, use, data capture and evaluation of performance of several complementary techniques for structural monitoring. Uniquely the application and time scale is set by an opportunistic set of circumstances which allows for a 'test-to-destruction' of a footbridge on the National Physical Laboratory (NPL) site at Teddington, as part of its redevelopment. This very advantageously gives unhindered access to the bridge to be investigated without inconvenience to the public or, for example, significant costs in rerouting traffic or travel to and installation of equipment at a remote site. The work planned involves close cooperation between staff at NPL, funded by the National Measurement System and by the DIUS working in conjunction with academics at City University and supported and advised by relevant industries, involving both the construction industry and a fibre optic sensor manufacturer. This work planned is to be carried out in collaboration with a major project supported by the Department of Industry, Universities and Skills (DIUS / the successor to DTI): Project AM14: Enabling the Next Generation of Structural Health Monitoring (SHM): Demonstrator, Validation and Best Practice by widening the scope of the entire study to include the input from City University and its expertise on fibre optic sensors. This aspect had not been included in the original DIUS-funded programme and the raison-d'tre for so doing arose from a recent opportunistic contact between staff at NPL and City University. Thus this specific application to EPSRC is for funding support for a small part of the planned work overall / for the direct, additional costs of the academic involvement in the project. It should be stressed that this is an application which if not supported at this time cannot be resubmitted in six months time: the opportunity to carry out these tests will have gone as by then the timescale for the work, in light of the demolition schedule, will have passed.

Building stone has a finite life that can be drastically curtailed when it is placed in the often-aggressive environments experienced in today's urban settings - yet stone masonry is still widely recognized as an adaptable and sustainable construction material, with a low carbon signature, and as a repository of much of the world's tangible cultural heritage. Arising from this, it is essential that the choice of new and replacement stone and the conservation of decaying stone is underpinned by a detailed knowledge of how different stone types decay in specific environments and what factors trigger decay and control its rate once it is initiated. Data are limited from the wide range of stone types seen in structures existing today - the performance characteristics of only a limited number of comparatively durable stones are known and these are largely resistant to physical damage and decay is driven primarily by dissolution. The rate of solution of stones is influenced by factors such as rainfall amount, timing, atmospheric conditions and chemistry and thus, with knowledge of micro-environmental conditions in and around the building stone, decay rates are largely predictable from short-term observation. Despite rather advanced non-destructive methods currently used for assessing the deterioration process and their rates, the fate and extent of inner contamination of building materials remains largely unaccounted for by such methods. Therefore qualitative online health monitoring of these building materials using embedded sensors is essential, not only from the standpoint of economic planning and maintenance, but also on cultural, technical and scientific grounds. Novel sensor systems designed specifically for use in buildings constructed from stone can provide the data that conservators need which enable them to understand better the complex processes that are on-going and to model better and thus plan repair and maintenance procedures in a cost efficient and timely way. This work builds upon several previous EPSRC grants into both fibre optic sensor systems, civil structural monitoring and heritage stonework. However in particular this follow on application builds upon the successful technical achievements of a grant focusing on the test, evaluation and design of a suite of new sensor systems for stonework monitoring for both moisture and chloride transport. The work enabled a more detailed evaluation of the decay processes and the beginning of a better understanding of several key applications-focused issues from that grant funded. Recognizing that the Follow-on Fund is concerned with development towards an identified commercial opportunity, this project can be summarized as the development, commercialization and marketing of fibre optic sensor systems for monitoring ingress of moisture and moisture-borne salts in the context of structural monitoring and decay prevention of stonework, both historic and modern. Through carefully considered technical and commercial plans, it is intended to refine the sensors for the specific monitoring environments of stone masonry strucures and develop probes which can be used in stonework in a minimal invasive manner. The commercial feasibility will be established through in situ evaluation, market testing and working closely with an SME with specialised knowledge in monitoring the built environment.

This project is designed to promote a synergy of the skills and expertise of key personnel in several key research groups, across a range of disciplines both in the UK and overseas, and working with targeted user communities to share their expertise and wide experience, with the people involved enthusiastically collaborating for success. In so doing, the prime theme of this project is to create new technological opportunities which would otherwise be very difficult to develop individually due to the limitations in individual facilities and resources and the depth of knowledge required, to create real innovation over a broad technological field. Most importantly, the focus of the application is on the team brought together to 'bring out the best' in a group of engineers with complementary skills, to achieve the step change that is needed to meet the challenges of competitiveness for the user community over the next decade and beyond. The consortium brought together for the first time, is one of significant diversity, which encompassing expertise and experience in optical fibre sensors, MEMS sensor design, fabrication and integration, chemistry, chemical engineering, communications and civil structures and has been created to make the step change in both the required sensor technologies and material science and thus developing a competitive edge to meet demands from user communities. The consortium has an excellent balance of experienced and early career staff, but above all is a group with the intellectual depth and drive to be successful, to take on new challenges and meet new opportunities.The project planned adds a new dimension to what is a very strong current grants portfolio of the UK consortium. The applicants hold a number of prestigious grants - amongst them 2 Platform Grants, 2 Challenging Engineering grants and 1 Advanced Fellowship (the latter two specifically recognizing excellence among early career researchers), together with a number of Responsive Mode grants and contracts with a strong KT dimension e.g. KTPs, which together emphasize meeting today's research needs.