The concrete industry has many special requirements that can be handled using magnets. The most obvious is the precast concrete panel industry.
In fact, any concrete product that is precast such as trench forms and prestressed concrete beams where the forms or moulds are usually made of steel and reused on a regular basis can benefit with the use of magnets.
We also find applications for magnets in high-rise buildings where the formwork is continually raised to form the next level as the concrete sets.