Innovative methods were used for the renovation of a quayside

Innovative methods were used for the renovation of a quayside

The quayside in Uddevalla was in great need of renovation as the existing construction was in poor condition. For some sections of the quay an innovative solution was used - that combines concrete and Leca® Lightweight Aggregate (LWA). 

The existing quay in Uddevalla, which lies along a river that goes through the city, needed to be rebuilt for two reasons. On one hand, stability needed to be improved to meet the current requirements, and on the other, safer high-water protection was needed to reduce the risk of flooding.

The design specification for the stability-enhancing measures and high-water protection was thus needed. A task that the Municipality of Uddevalla allocated to two companies, Bohusgeo and Port Engineering.

Bohusgeo is a consulting company with long experience of conducting geotechnical investigations. Port Engineering specializes in quay structures and port facilities. Both companies are based on the West Coast of Sweden and have great local knowledge of the area.

Reinforced lightweight aggregate concrete slab

Based on the conditions of the area and the requirements of the design, BohusGeo and Port Engineering suggested a solution that in Sweden is called LLP.  LLP is a reinforced lightweight aggregate concrete slab. It provides a light and relatively rigid construction. Henrik Lundström, a geotechnician working at Bohusgeo, was one of the people involved in the project.
- The reason for choosing LLP as a solution was because of stability for the new construction and partly because of settlement issues in the area, says Henrik Lundström.
LLP is a method that is well suited for filling that needs to be able to withstand large loads and settlements problems.

Innovative solution 

The contract was subsequently assigned to PEAB and the majority of the work on the quayside was completed in 2018.

Installation of the LLP-solution is done by combining Leca LWA and cement mixture (also called slurry) in a specially developed nozzle. The mass with the two combined materials is laid out and packed in layers with welded mesh reinforcement. The total thickness of the slab is normally 0.3-0.5 meters. In this project, a design was chosen in which loose Leca LWA was also put on top of the finalized slab. The reason for doing this was to compensate the load and minimize settlement. 

- Our innovative method where we combine concrete and Leca LWA has a number of advantages. In addition to only give small and, above all, even settlements, execution is also quick and easy, says Ola Andersson, Sales Manager at Leca Sweden.