For the new construction of the sewage treatment plant, Leyrer + Graf relied on both the software and the sensor technology from CONTAKT. The clarifier of the plant was designed as a so-called “white tank” and made of water-resistant concrete. Naturally, the highest demands were placed on the tightness and quality of the concrete – the perfect field of application for CONTAKT.

Logo von Kunde Leyrer und Graf, der CONTAKT build & hub nutzt
Rohbau mit Verschalung und Gerüst ist ein Bauprojekt von Leyrer und Graf mit CONTAKT build & hub
The project during the construction phase

It was crucial for the success of the project to ensure a tension-free construction and to avoid cracks in the concrete, e.g. due to temperature changes during the curing phase. In order to monitor the temperature profile of the concrete during the curing phase, the CONTAKT sensors were attached to the concrete walls. Together with the site team, CONTAKT developed a novel method, which made it possible to keep the sensors in the concrete and have them collect temperature data even after the formwork walls had been removed. The data collected by the sensors was sent to the gateway using LoRa wireless technology and from there fed into our database.

In addition, a so-called concrete calibration was used to determine the compressive strength curve of the concrete mix used specifically for this project.


  • Project: Sewage treatment plant Pulkau
  • Building type: Sewage treatment plant
  • Location: Pulkau
  • Construction start: August 2021
  • Number of sensors: 20 sensors and 1 gateway
  • Rough-in time: Aug. – Dec. 2021
Nahaufnahme einer Doka Verschalungselements mit integriertem CONTAKT build & hub Übertragungssensor
Sensor with transmission unit in use

It was a very exciting project for us, because it combined traditional construction methods with state-of-the-art digital technology. Data is also essential for us to continuously optimize our construction processes. Now it’s a matter of evaluating and analyzing the key performance indicators.”

Patrick Ullrich, Head of Digitisation & Innovation Leyrer + Graf

For this construction site, the project management relied on the three modules of our CONTAKT software:CONTAKT buildmade it possible to plan the division of the structure into cycles and work steps in advance. The cutting function, a special feature of CONTAKT, proved to be particularly helpful here, allowing larger components to be divided into several work cycles, including quantity evaluation.

The CONTAKT app made it possible to track the completed work steps in real time, including approval and photo documentation. This enabled the project manager to keep track of the construction progress without having to be on site all the time.

InCONTAKT hub, the collected data could be evaluated and cycles with potential for improvement could be identified. For this purpose, the effort values of the individual work cycles were dynamically compared with each other.