Reinforcement braking and approach area - Junction Hardstrasse - Kölliken, Switzerland

Crack Prevention

Reinforcement braking and approach area - Junction Hardstrasse - Kölliken, Switzerland

Massive ruts and cracks in the road surface made rehabilitation of the Hardstrasse - Köllikerstrasse - Suhrentalstrasse junction unavoidable. Due to the high traffic load, those responsible decided to use asphalt reinforcement in this area.

Reinforcement braking and approach area
Junction Hardstrasse


The Hardstrasse - Köllikerstrasse - Suhrentalstrasse junction is located in the immediate vicinity of the Aarau-West motorway exit on the A1. From the southbound exit, the through road opens up the Suhrental valley all the way to Lake Sempach. On the axis from east to west, the road connects the towns of Kölliken and Muhen. Due to this location alone, there is a high volume of traffic on these roads every day. In addition, a large gravel plant, a haulage company and a distribution centre of a feed supplier are located to the west of the junction. 

Therefore, heavily loaded lorries put a strain on the road surfaces in this region every day. In the area of the crossing, this leads to very high loads, especially when the lorries brake and accelerate. An inspection prior to rehabilitation by the road owners, engineers and experts from S&P showed in 2011 that massive ruts and large cracks had formed.


Due to the initial situation and the damage patterns, it was decided to reinforce the entire intersection and the braking areas of the roads with S&P Carbophalt® G. For this purpose, the old surface course was milled off and any cracks in the binder course were filled with bitumen. This was followed by a bitumen emulsion to ensure the bond between the binder, reinforcement and wearing course. The S&P application experts laid a total of 5300m² of asphalt reinforcement with the special Avant vehicle. The road construction company then laid the new wearing course.

Barely any cracks in the reinforced area

An inspection in 2022 showed that ruts had formed again in the braking and approach areas of the junction, but apart from a few small exceptions there were no cracks in the area of the asphalt reinforcement. The situation was completely different in the road areas in front of the reinforcement, which can be clearly distinguished from the area reinforced with S&P Carbophalt® G: Numerous longitudinal and transverse cracks are visible, some of which are already several metres long and have already been repaired. This is despite the fact that the areas are less heavily stressed by deceleration and acceleration than those directly in front of and within the junction.

Less traffic disruption

The example of the Hardstrasse - Köllikerstrasse - Suhrentalstrasse junction shows that cracks in the wearing course can be prevented with S&P asphalt reinforcement grids. This allows cantons as well as municipalities to save costs for crack and wearing course rehabilitation. At the same time, traffic at important junctions is less affected by poor road conditions and road works, which can lead to frustration and delays for road users.

Image Gallery

  • The comparison picture shows where the S&P asphalt reinforcement was installed in 2011 and how the area looks in Spring 2022. Image: S&P

  • Before the rehabilitation, there were deep ruts all around the junction. Image: S&P

  • The loads led to numerous and large cracks in the wearing course. Image: S&P

  • After milling, deeper cracks were filled with bitumen. Image: S&P

  • The entire junction and up to 80m of the roads were reinforced with S&P asphalt reinforcement. Image: S&P

  • In 2022, there were indeed ruts again in the reinforced area. Image: S&P

  • However, no significant cracking or damage to the wearing course has occurred to date. Image: S&P

  • In the sections before the junction that were not reinforced with S&P grids, cracks can already be seen again. Image: S&P

  • An overview of the junction, the gravel plant is clearly visible in the west. Image:


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