Calculated Ready for Spraying!

Shotcrete is a very simple and efficient solution for many applications. However, the necessary calculations for planning were very effortful until now. With a new digital tool, the process can now be simplified.

In some planning offices, some ancient computers with Windows XP are still artificially kept alive. The CD with the calculation programme for shotcrete reinforcements can still be used on these computers. The application of shotcrete is particularly suitable for renovations or conversions of buildings, for example because new uses are planned that change the statics of the building. Shotcrete can be applied very easily without formwork in these cases, making it an efficient and cost-effective solution. However, as practical as the process is in application, calculating the necessary thickness of the shotcrete to be applied, as well as the required reinforcement, is still complex.

“The planners have to take into account various sets of rules for these calculations“, Sarah-Maria Haug, Structural Engineer at ZÜBLIN since 2016, says, “and a large number of publications must be sifted through for any further verification obligations“. With a team led by Dr Marcus Walz in the ZÜBLIN Structural Maintenance Subdivison, Haug has developed a web-based solution that guides them step by step through the many calculations and displays all the verification obligations. With this solution, for which Haug developed elaborate iterative calculations in the Excel programme and programmers designed algorithms, the very complex calculations can now be carried out and documented simply and reliably. An initial assessment of feasibility can be made in just a few minutes, and in a few hours, a detailed structural analysis is ready for approval.

Higher mathematics – working with shotcrete is an efficient method but requires complex and time consuming calculations in planning.

For her work on innovations like this calculation tool, Sarah-Maria Haug receives a lot of support in the Group: “I always get the opportunity to participate in the Group’s research projects or support with research funding applications for my own R&D projects. The only thing that is never available in sufficient quantities is time.

Legal hurdles

Dr Marcus Walz, sees STRABAG as a pioneer in the construction industry in terms of innovative strength:

“The size of the group also helps here; we have the necessary capital, a wide range of competences and sufficient application possibilities to simply try out new ideas and technologies and, if necessary, to be able to say that they have not proved successful.”

However, Dr Walz and his team are convinced that the calculation tool for shotcrete will prove its worth. On the way to a marketable solution, potential legal hurdles had to be overcome in addition to the technological challenges, especially in the area of competition and data protection law. The disclaimer also required legally secure formulations.

There is no comparable solution on the market so far. Dr Marcus Walz expects this simplification to increase demand for shotcrete applications, which are offered, for example, by the STRABAG subsidiary Torkret. The new calculation tool is initially geared towards beams and slabs in combination with steel; in the future, solutions for columns and a combination with carbon fibres instead of steel are to be added.

Concrete spraying is particularly suitable for renovations or conversions of buildings..

In any case, this web-based solution means that even the last planning offices can now dispose of their old emergency computers and carry out their calculations in future from anywhere in the world, even in the home office.

For more information on shotcrete, see:
www.spritzbetonverstaerkung.de