Ageing of safety nets: understanding the phenomena and analysing the testing methods

Safety nets are fitted when falls from height cannot be avoided by other collective protection means. Performance of the nets is assessed in compliance with Standard EN 1263-1. That standard specifies lengthy and tedious natural or artificial ageing testing for new nets, and recommends they be monitored during their use, but such monitoring is rarely performed by the users. This study proposes to investigate the following fields:
- updating knowledge on mechanical strength and ageing of nets;
- establishing a relationship between natural and artificial ageing, and, if possible, defining an artificial ageing method that is representative and short;
- defining pragmatic means for assessing ageing of nets;
- examining the utility of deepening the knowledge on chemical ageing of the nets so as to gain a better understanding of how their mechanical characteristics change over time.
The study will concern nets having different characteristics, subjected to different types of natural and artificial ageing. The mechanical properties of samples of nets will be monitored over time in order to characterize and understand the changes over time in the phenomena involved.
The results of this study will make it possible to update knowledge on ageing of safety nets, to assess the relevance of the standardised methods of testing new nets, and possibly to propose improvements to such testing. In addition, a method enabling users to monitor ageing of nets while they are in use will be proposed.

Planned dissemination:
- publication in the journal “HST” and in building trade journals;
- publication in a scientific journal;
- information to the European Committee for Standardization (CEN).