Stone is widely recognised as a sustainable construction material and as a store of much of the world's tangible cultural heritage. With this recognition has come an understanding that stone has a finite life that can be drastically curtailed when it is placed in the often-aggressive urban environments. In particular, many common building limestones experience seemingly unpredictable, episodic and sometimes catastrophic breakdown as stone strength is exceeded by gradual decay, the slow accumulation of internal stresses and/or subjection to extreme external stresses such as a severe frost. Episodes of rapid decay may be interspersed with periods of relative stability marked by, for example, the formation of pollution-derived calcium sulphate crusts. To control potential catastrophic decay it is therefore necessary to understand why rapid retreat is triggered, what allows it to continue, how it can be halted and how the causes can be avoided in the first place. This is particularly true where inappropriate conservation could accelerate decay, and where choices have to be made between possible replacement stone and stone selection in relation to new structures. To achieve this understanding four questions need to be asked.1. What processes are responsible for rapid retreat?2. What physical, chemical and mineralogical characteristics determine stone susceptibility to rapid retreat and how do these properties change during decay?3. How do microclimatic conditions at and beneath the stone surface change as stone retreats and how do these influence decay mechanisms?4. What permits continued weathering despite rapid loss, of weathered material in which, for example, damaging salts are concentrated?This interdisciplinary project will examine these questions through field studies of stone structures in Oxford and nearby areas built of oolitic limestone (e.g. Bath and Cotswold limestones) that is prone to rapid retreat. Linked to this will be the development of fibre optic sensors that will allow moisture and salt movement within individual blocks to be monitored in relation to environmental conditions, including temperature, relative humidity and surface wetting. These data, and the same sensor technology will be combined with analyses of weathered stone to design laboratory experiments using different varieties of Bath Stone to simulate breakdown patterns and the dynamics of salt and moisture movement as blocks retreat and are progressively sheltered. Results from field studies and controlled laboratory experiments will be combined to explain (model) the factors that determine overall susceptibility to either rapid retreat or stability and the operation of the processes responsible for decay. In particular, results will be used to determine what triggers positive and negative feedbacks that respectively accelerate and decelerate change within the stone decay system. This understanding will be used, in discussion with end-users, to develop protocols for limestone conservation and the selection of new and replacement stone matched to specific environmental conditions.

The Chinese 11th Five-Year Plan considers Sustainable Energy Supply and Sustainable Built Environment as crucial for achieving sustainable development. Recognising the potential benefits, the UK government has actively encouraged international collaborations with China. Two Engineering Schools at Queen's University Belfast (QUB), with internationally recognised research excellence in the Built Environment and in Electric Power & Control, have taken used these opportunities to collaborate with a number of, geographically distributed, leading Chinese universities, research institutions and industries. This effort has been supported by the EPSRC, the Royal Society & the Royal Academy of Engineering, and includes a 1M EPSRC grant for a UK-China joint consortium on sustainable electric power supply and a 220K EPSRC project to run UK-China Network of Clean Energy Research to promote SUPERGEN (Sustainable Power Generation and Supply) in China. Some QUB technologies have also been tested in major construction projects, such as the Beijing National Olympic Stadium (Bird's Nest) and the Hangzhou Bay Sea-Crossing Bridge (longest such bridge in the world). The applicants aim to enhance their science innovation and technology transfer activities in both China and the UK helped by their 7 university partners (principally Tsinghua University, # 1 in China & Zhejiang University, #3 in China, the others being Chongqing, Shanghai Jiaotong, Southeast, Shanghai and Hunan), 3 Chinese research institutions (Central Research Institute of Building & Construction CRIBC, the Chinese Academy of Sciences Institute of Electrical Engineering, and the Research Institute of Highways). The China State Railway Corp. (largest under Ministry of Railways), the China State Construction Corporation (largest under Ministry of Construction), Bao Steel Corporation (largest in China, #6 in world sales) and Shanghai Electric Group (largest in China) are the main 4 Chinese industrial partners. Complementary UK support includes Amphora NDT Ltd, Macrete and SUPERGEN.

Stone is widely recognised as a sustainable construction material and as a store of much of the world's tangible cultural heritage. With this recognition has come an understanding that stone has a finite life that can be drastically curtailed when it is placed in the often-aggressive urban environments. In particular, many common building limestones experience seemingly unpredictable, episodic and sometimes catastrophic breakdown as stone strength is exceeded by gradual decay, the slow accumulation of internal stresses and/or subjection to extreme external stresses such as a severe frost. Episodes of rapid decay may be interspersed with periods of relative stability marked by, for example, the formation of pollution-derived calcium sulphate crusts. To control potential catastrophic decay it is therefore necessary to understand why rapid retreat is triggered, what allows it to continue, how it can be halted and how the causes can be avoided in the first place. This is particularly true where inappropriate conservation could accelerate decay, and where choices have to be made between possible replacement stone and stone selection in relation to new structures. To achieve this understanding four questions need to be asked.1. What processes are responsible for rapid retreat?2. What physical, chemical and mineralogical characteristics determine stone susceptibility to rapid retreat and how do these properties change during decay?3. How do microclimatic conditions at and beneath the stone surface change as stone retreats and how do these influence decay mechanisms?4. What permits continued weathering despite rapid loss, of weathered material in which, for example, damaging salts are concentrated?This interdisciplinary project will examine these questions through field studies of stone structures in Oxford and nearby areas built of oolitic limestone (e.g. Bath and Cotswold limestones) that is prone to rapid retreat. Linked to this will be the development of fibre optic sensors that will allow moisture and salt movement within individual blocks to be monitored in relation to environmental conditions, including temperature, relative humidity and surface wetting. These data, and the same sensor technology will be combined with analyses of weathered stone to design laboratory experiments using different varieties of Bath Stone to simulate breakdown patterns and the dynamics of salt and moisture movement as blocks retreat and are progressively sheltered. Results from field studies and controlled laboratory experiments will be combined to explain (model) the factors that determine overall susceptibility to either rapid retreat or stability and the operation of the processes responsible for decay. In particular, results will be used to determine what triggers positive and negative feedbacks that respectively accelerate and decelerate change within the stone decay system. This understanding will be used, in discussion with end-users, to develop protocols for limestone conservation and the selection of new and replacement stone matched to specific environmental conditions.

Abstracts are not currently available in GtR for all funded research. This is normally because the abstract was not required at the time of proposal submission, but may be because it included sensitive information such as personal details.

The premature deterioration of concrete structures is a world-wide problem. In most developed countries, including the UK, around 50% of the construction budget is devoted to repair and maintenance of structures with over 30% of this expenditure on concrete structures. In addition, our infrastructure has now reached an age where capital costs have decreased, but inspection and maintenance costs have grown, constituting a major part of the recurrent costs of the infrastructure. Traffic delay costs due to inspection and maintenance programmes are already estimated to be between 15%-40% of the construction costs . Demands for enhanced performance create a pressing need to be able to determine, with an acceptable degree of confidence, the anticipated service life of concrete structures. Monitoring deterioration would provide an early warning of incipient problems enabling the planning and scheduling of maintenance programmes, hence minimising traffic delays resulting from road/lane closures. The development of integrated monitoring systems for new reinforced concrete structures could also reduce costs by allowing a more rational approach to the assessment of repair options; and, co-ordination and scheduling of inspection and maintenance programmes. It is now recognised that integrated monitoring systems and procedures have an important role to play.in the total management of structures, which involves both whole-life economics and life-cycle calculations, When data from monitoring systems are used with improved service-life prediction models additional savings in life cycle costs could result. Recent reports from both CIRIA (2008) and EPSRC (2009) highlight the need for the development of sensor technology for 'intelligent' montoring of structural health.Since it is the concrete cover-zone (covercrete) which protects the steel from the external environment, the ability to continuously monitor the covercrete would allow a more informed assessment of the current and future performance of reinforced concrete structures. In-situ monitoring of cover-zone concrete - in real time - could thus assist in making realistic predictions as to the in-service performance of the structure; likely deterioration rates for a particular exposure condition, compliance with the specified design life and as an early warning indicator of incipient problems. Set against this background, this proposal exploits previously funded studies to deliver an intelligent, durability monitoring system thereby addressing a pressing need in the total management of concrete structures. The development of sensors and associated monitoring systems to assess covercrete performance would thus form an important component in the inspection, assessment, maintenance and management of structures.This follow on funding proposal addresses this subject. A patent application has recently been filed detailing a multi-electrode electrical conductivity and temperature array and rebar attachment facility (Patent No. 0918449.0). The array gives a detailed picture of the spatial distribution cover-zone properties and their variation with time i.e. it allows an integrated assessment of the cover-zone response to the external environment. The thrust of the proposal will be further technical development of the testing methodology and monitoring technology so as to provide a 'market-ready' product for intelligent monitoring of concrete structures.