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Subsurface Radar as a Tool for Non-destructive Testing & Assessment in the Construction & Building Industries

Objective



Objectives and content

There has been a tremendous growth in the use of subsurface radar since the early 1980's. The main applications have involved shallow geological evaluation and non-destructive testing investigations. The equipment transmits pulses of electro-magnetic energy, generally at microwave frequencies, and receives reflections from interfaces where there is a discrete change in material electrical properties. In the case of buildings and other forms of construction, the technique enables information to be gathered about the nature of the structure and aspects of its condition. There is potential for the use of the technique as a means of assessing quality and condition during the process of construction. This RTD proposal brings together complementary expertise and interests from a range of organisations with industrial and research backgrounds in 4 countries; Germany, Italy, Norway and United Kingdorn, of different sizes (SME's to IND 7) and whose roles within the industry represent all aspects of the application and use of the radar technique; suppliers and developers of equipment, service providers and those who use the data obtained as a tool in their normal business. This gives a unique perspective upon industrial requirements for radar surveying and means of developing and delivering these.

The proposed RTD project seeks to extend existing knowledge by studying the dielectric properties of brick and stonework, concretes and aggregates, by improving current dielectric models and by studying the response of a number of radar systems to construction and material features incorporated in laboratory physical models and by field studies. Topics to be investigated include multi-layer reinforcement and prestressing provision within structural concretes, the presence of moisture, porosity and salinity within construction materials and the detection of defects and damage within structural elements. An objective of the research is to improve current abilities to evaluate these parameters. These prospective advances will be supported by the investigation of the benefits and limitations of higher frequency antennas, equipment developed in the RTD project could possibly form the basis for subsequent demonstration high frequency equipment; the investigation of better means of capturing and processing data, to improve the recognition and classification of defects and other construction related features; and by the use of analytical modelling methods. It is intended that this activity will result in software developments for diffraction tomography and for the evaluation of the suitability of radar in particular circumstances and in the application of neural networks and knowledge based systems to radar data.
Potential economic benefits and opportunities could arise from the direct sale of equipment and software products and services and, perhaps more significantly economically, indirectly from (a) improvements in the quantification of aspects of the standard of new construction and remedial works, and (b) the maintenance and assessment of vulnerability and prevention of damage to buildings and infrastructure assets such as bridges, monuments, tunnels, etc. The RTD work would also contribute to the development of standards and working practice by providing supporting scientific and technical knowledge needed in these areas. The standard of safety in new and existing structures could be enhanced and the techniques would help in better targeting the resources available for remedial or preventative works. Potential benefits of the above might be exploited in various ways. These indude the development of commercial radar systems and software; perhaps taking a further two years once the basic scientific and technological principles had been established in the RTD project. The expertise and experience of the project participants could be used to provide advanced surveying and investigation services on a commercial basis. In the wider context such services could assist major construction companies evaluate financial risk when seeking to develop major schemes for the refurbishment and subsequent maintenance of large elements of infrastructure on the basis of "finance, maintain and operate" types of contract.

Funding Scheme

CSC - Cost-sharing contracts

Coordinator

HOCHTIEF AG
Address
Bockenheimer Landstrasse 24
60323 Frankfurt Am-main
Germany

Participants (7)

Building Research Establishment Ltd.
United Kingdom
Address
Bucknalls Lane
WD2 7JR Watford - Garston
Bundesanstalt für Materialforschung und Materialprüfung
Germany
Address
87,Unter Den Eichen
12205 Berlin
Ismes SpA
Italy
Address
Via Giulio Cesare 29
24124 Bergamo
Norwegian Geotechnical Institute
Norway
Address
72,Sognsvn.
0806 Oslo
POLYTECHNIC OF MILAN
Italy
Address
Piazza Leonardo Da Vinci 32
20133 Milano
STRUCTURAL TESTING SERVICES LTD
United Kingdom
Address
Empress Road 179, Empress Park 4A
SO14 0JX Southampton
University of Liverpool
United Kingdom
Address
Abercromby Square
L69 3BX Liverpool