Site installation and testing of a continuous acoustic monitoring

摘要

In recent years much experience has been gained with continuous acoustic monitoring of monostrands and stay cables. However, there is little knowledge with monitoring of post-tensioned bridges with bonded tendons. An acoustic monitoring system has been installed on a road bridge to evaluate its diagnostic performance. This bridge, the Ponte Moesa, is one of the first prestressed concrete bridges in Switzerland. Insufficient grouting and de-icing salts among other causes have led to deterioration and wire breaks. Blind tests have been conducted generating artificial wire breaks by means of electrolytic corrosion-cells. Additionally, several spontaneous wire breaks occurred. To evaluate the applicability of acoustic monitoring, the results were compared with those of a conventional invasive examination and those of potential mapping.