The A4 between Küssnacht and Brunnen is a highly frequented highway. In order to minimize traffic disruptions as much as possible, for the first time ever, Zurich-based KIBAG AG supplied UHPC to the construction company responsible for renovating three highway bridges. This is a particularly durable construction material which differs greatly from conventional concrete. Extremely fine-grained aggregates, a high proportion of binder, additives and steel fibers guarantee particularly high material strength and deformability as well as short drying periods. This significantly reduces the construction time. For KIBAG, the reconstruction of the A4 route is also an important test and reference project for this new specialist concrete:
The mixing process is of decisive importance here as this special concrete puts great demands on mixers due to its special composition. More specifically, UHPC requires an extremely high energy load, as well as reliable and durable technology. As the production of UHPC requires outstanding knowledge of mixing processes, an ultra-modern, mobile mixing system was commissioned from BHS. BHS selected the twin-shaft batch mixer as the core system component. The three-dimensional mixing concept is one of the mixer’s main features. The turbulent overlap zone of the two mixing circuits generates an intense material exchange, as well as very high relative movement, which is a basic requirement for manufacturing UHPC.