Uni Irchel Underpass, Switzerland

Case Study Description

Within the scope of the Schwammendingen enclosure project, the Winterthurerstrasse serves as an important bypass. In order to guarantee a smooth flow of traffic, the Uni Irchel underpass and the traffic connection at Winterthurerstrasse were repaired.

The overall repair of all concrete elements of the underpass was carried out in two phases on account of the traffic. The chloride-contaminated and damaged concrete in the underpass and curb walls was removed with high-pressure water jets and the locally damaged reinforcement replaced where necessary. All of the concrete surfaces could then be provided with new protection. Various types of concrete and mastic asphalt were used as a seal.

The entire road surface on the project’s perimeter had to be replaced. Some of the areas displayed numerous deep cracks. The surface structure consisted of a binder course and a top course with a total layer thickness of 110 mm. At the same time, the manhole covers and gullies were replaced in the entire area.

The road surface was replaced in four phases, the last two of which were carried out over two weekends in September in two-shift operation following the overall repair of the concrete elements.