In 2022, the Petteril Bridge in Carlisle was damaged during the derailment of a freight train carrying cement wagons. The official reports indicate the derailment was a result of false flanges that caused rail wheels to stop rotating. Fortunately, there were no casualties nor injuries, but the accident did result in several weeks of line closures on the Newcastle route. Emergency repairs were carried out by Network Rail, the organization in charge of developing railway infrastructure in England, and for the repairs to succeed, the project required the removal and renewal of a deck and retaining wall. This had to be completed before the track could be re-laid, allowing the route to be reopened. Fortunately, Network Rail was able to contract Hanson UK to take on the technical reins of the project.
One of the essential challenges for Hanson UK was to provide a pumpable high early strength waterproof concrete mix that would achieve 50N/mm2 strength within a few days after placement. Additionally, the bridge deck required 38m3 and the retaining wall 15m3. To accomplish this, Hanson UK was set to use its usual process of lab test cubes to determine concrete strength. However, the Petteril Bridge project required fast decision-making, not only for the route reopening but, most importantly, for monitoring high early-strength concrete. Waiting for cube test results would pose a significant challenge due to the long wait times and delays.
In order to meet the requirements of time and strength, Hanson UK had the perfect ace up its sleeve, SmartRock® concrete sensors. Hanson UK provided high early strength concrete and technical assistance for which SmartRock was essential for its success. The wireless sensors provided strength data 24/7 and in real-time, avoiding the delays of cube testing results. The rapid availability of this data was crucial as it can monitor the specific strength needed for early-age concrete, which differs from other kinds of concrete.