Quality Control and Monitoring of FRP Applications to Masonry Structures

Abstract:  The use of composite materials in strengthening and restoring interventions on existing structures is continuously increasing. During the last decades, many researchers have developed new strategies, technical solutions and analyses. In particular, the Italian CNR DT 200/2004 technical recommendations for the design and construction of strengthening techniques with fibre-reinforced composite material (FRP) systems have been published to provide an aid to designers interested in the field of composite materials and to avoid their incorrect application. The Guidelines deal with different types of FRP applications both to masonry and reinforced concrete structures and take into account several tests for the quality control and monitoring of FRP installation. In the present study, the results of semi-destructive and non-destructive techniques conducted for the quality control and monitoring of FRP applications to masonry, according to CNR DT 200/2004 Guidelines, are reported. Pull-off tests and shear-tearing tests were performed on real brick and natural stone masonry buildings for the assessment of the quality of FRP application. Finally, non-destructive tests were carried out to characterise the uniformity of FRP installation by means of thermographic tests. Different types of FRP fabrics have been adopted. The tests allowed the validation and assessment of procedures, methods and theoretical relationships suggested in the Guidelines.     

Accidents,often the result of an ‘uncontrolled business process’—a study in the (Dutch) chemical industry

Often companies in the (petro‐) chemical industry claim that all possible countermeasures against potential accidents have been taken and therefore accidents are unforeseeable. In this paper we question this statement by analysing the pre‐warning signals (precursors) preceding a number of industrial accidents. 17 accidents that occurred in the (petro‐) chemical industry have been investigated by exploring FACTS, an accident database containing information about industrial accidents worldwide. This paper will demonstrate that the existence of precursor information could have been used to foresee and even prevent these accidents if a proper control action had been initiated. The accidents are analysed further, according to a control model, which was adapted from that of C. Argyris. It demonstrates the ineffectiveness of several elements of business process control loops and that the so‐called ‘double‐loop learning’ cycle is more important than the ‘single‐loop learning’ cycle if one considers safety improvement. Copyright © 2003 John Wiley & Sons, Ltd.