Details

Autor(en) / Beteiligte

• Cheng, Hao
• Zhang, Fengqiao
• Yang, Yuguang
• (Kees) Blom, C.B.M.
• Casas, Joan-Ramon
• Turmo, Jose
• Frangopol, Dan M.

Titel

Monitoring of repaired concrete floor in the Maastunnel using smart aggregates

Ist Teil von

• Bridge Safety, Maintenance, Management, Life-Cycle, Resilience and Sustainability, 2022, p.493-500

Auflage

1

Ort / Verlag

CRC Press

Erscheinungsjahr

2022

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• The Maastunnel, constructed in 1942, is the first immersed tunnel with a rectangular shape. This tunnel is considered as the prototype of the modern immersed tunnels and heritage construction in the Netherlands. Since 2018, a renovation of the Maastunnel has been carried out due to the extensive corrosion of the reinforcement observed at its bottom floor. The old concrete surrounding the rebar was removed. And, after cleaning the reinforcement, a new concrete layer was cast. In order to monitor the quality of the repaired layer and detect the possible deficiency in terms of delamination between the existing and the newly-cast concrete, a monitoring system was installed in this tunnel, which makes use of embedded piezoelectric sensors named smart aggregates. A total of six smart aggregates, two in new concrete and four in old concrete, were used in the monitoring process, and the monitoring has been running for more than 757 days after the installation. In this paper, we demonstrate the usage of the monitoring data in identifying the hardening process of the newly-cast concrete and monitoring the quality of old-new concrete interface. The test results show no visible delamination between the new and the old concrete up to now. Moreover, the smart aggregates show a stable performance during the two-year monitoring, which illustrates their reliability in the long-term monitoring of concrete structures. The Maastunnel, constructed in 1942, is the first immersed tunnel with a rectangular shape. The old concrete surrounding the rebar was removed. This chapter demonstrates the usage of the monitoring data in identifying the hardening process of the newly-cast concrete and monitoring the quality of old-new concrete interface. The delamination in concrete structures can be seen as structural damage along the interface. The former is due to the stronger attenuation caused by the crack opening, while the latter is highly related to the macro-crack-sensitive arrival time. The travel time of waves that across the interface contains three parts: travel time in old concrete, travel time in new concrete and travel time across the interface. This chapter demonstrates the usage of the monitoring data obtained from embedded sensors, SA, in Maastunnel for monitoring both the interface between new-old concrete and the hydration process of new concrete.