BAM Nuttall

London City Airport


BAM Nuttall




Predicting curing times to >95% accuracy

The Bam Nuttal team at City Airport, responsible for the piling and decking phase of a major airport expansion project, enlisted Converge’s technology to help keep this major project on schedule. This was the first live project to make use of Converge’s Concrete Strength Predictions engine; an intelligent algorithm that combines our proprietary concrete performance dataset with local weather feeds, allowing our customers to see with >95% accuracy when their pour will reach strength.


The London City Airport extension, owned by BAM Nuttall,  is a major civils project designed to deliver a brand new  taxiway which increased the airport’s capacity as part of its  £500m expansion. This expansion allows annual passenger  numbers to grow from 4.5m to 6.5m.


A barge was constructed over the open water to reach the  physical location of the new taxiway. The team then placed  sensors at key points taking into account the sequencing of  pile cages and decking stitches. Sensors were placed along  65 pours in pile caps and slabs.

Due to the site layout, moving around the pouring area was a complex task. Our concrete monitoring system collected real-time data and provided accurate predictions of pour curing times which helped Bam Nuttal better use their time by improving communication with stakeholders, project planning, and better, make data-driven decisions.

Client Challenge

The piling and decking team faced several challenges given the unique nature of the project.  

The taxiway was constructed over open water where weather conditions are variable. This meant that typical methods to estimating curing time such as cubes had been unrepresentative compared to actual in-situ concrete curing which is greatly affected by ambient temperature. The mixture being used was a special Cem 1 air-entrained mix specifically chosen for its resilience to the weather and the water. It has thousands of tiny micro-air pockets into which water can expand when it freezes, reducing pressure on the concrete. To keep the air in the concrete, it has to be pumped around 300m across the dock.  

Finally, the airport itself, a high traffic area in the City of  London with its small footprint meant that the site team were operating with significant space constraints alongside the challenge of organising site logistics and deliveries.  This was made even more complex given the majority of works could only be performed at night and outside of usual working hours for most suppliers.

The team were able to easily set key milestones onto the  Converge platform, allowing for automatic alerts as soon as pours reached key strengths. This data was available on our platform 24/7 with zero latency.

To better plan resources, machinery and deliveries just in time, the city airport team made use of Converge’s  Concrete Strength Predictions Engine to look ahead and plan accordingly.

Value & Benefits

The Power of Prediction

The use of our Concrete Strength Predictions Engine not only allowed the site team to strike at the earliest, safest opportunity but also to proactively plan the resources needed to complete critical path activities in advance, without having to wait for a cube to be crushed.

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