Page tree
Skip to end of metadata
Go to start of metadata

Building with Nature Guideline
The content of the Building with Nature guidelines was moved to
Click the link above if you are not automatically redirected within 10 seconds.

Home BwN Approach Building solutions Projects Toolbox

 Building with Nature Guideline > Projects > Eco-concrete breakwater structures - IJmuiden, NL

Log in  


Eco-concrete breakwater structures - IJmuiden, NL


Location: IJmuiden Harbour, The Netherlands

Date: 2008 - 2009
Involved parties
: Deltares, Ecoconsult, BAM DMC, RWS Noord Holland, Microbeton, C-Fix
Technology Readiness Level
: 7 (successful pilot case)

Environment: Estuaries

Keywords: Concrete, breakwater, biodiversity

Building with Nature designTraditional design

Concrete blocks with eco-friendly surfaces, roughened with various textures and geometric shapes, stimulate fast and diverse colonization by macro-algae and macro-fauna. Eco-concrete stimulate re-growth and biodiversity in exposed environment.

Traditional concrete blocks with relative smooth surfaces and reduced potential for species colonization.


The breakwaters at the entrance of the North Sea Channel at IJmuiden (The Netherlands) protect the port against wave attack. The breakwaters consist of regularly placed 2 m x 2 m concrete blocks. The surface of the blocks, with cracks and spaces between these blocks are habitats for a diversity of marine flora and fauna like algae, insects, crabs and shellfish, fish and birds (including species on the red list). Because of this, it is important that during and after renovation of breakwaters, the affected hard substrate habitats is able to recover quickly. This can be stimulated by the use of special concrete blocks, which is investigated in this pilot study. Eco-concrete will stimulate re-growth and biodiversity in exposed environment.

 Read more



A pilot study was set-up to investigate the possibility to increase the settlement of algal and macro-fauna colonization by testing various textures and geometrical shapes on the concrete blocks of one of the breakwaters ('Zuiderhavenpier') of IJmuiden harbour in 2008-2009. In 2011, a renovation of the breakwaters of IJmuiden Harbour was planned. To stimulate the recovery of the ecological system at the breakwaters, the IJmuiden Port Authority had interest in using eco-concrete. The project was proposed by Deltares, based on funding by Rijkswaterstaat Innovation Program (WINN). Various parties such as Ministry of Public Works - Rijkswaterstaat and  BAM DMC  contributed to the project by providing materials, transport and additional funding.


Planning and design

The eco-slabs have a size of 75 cm x 50 cm and have six different textures/shapes of 25 cm x 25 cm at the top surface. The eco-slabs were attached both horizontally and vertically to the concrete blocks. The textures and geometrical shapes for the vertically placed slabs were slightly different from for the horizontal ones.

 Read more


The eco-slabs have been constructed using moulds and are made of various types of concrete. They were attached to one of the breakwaters (Zuiderhavenpier) of IJmuiden harbour in April 2008. The breakwater consists of concrete blocks of 22 and 30 metric ton embedded in asphalt. In total, 20 slabs have been placed from low water to high water mark; 10 were placed in wave exposed locations and 10 at sheltered locations. The aim of this variation is to determine the optimum position for the various textures with respect to water level. The slabs were placed using a crane and mounted to the concrete blocks using bolts and nuts.

 Read more


Operation and Maintenance

Analysis of the photographs taken of the sections on the slabs showed that the sections on the slabs with a fine or coarse surface were colonized more rapidly by small green algae (Ulothrix flacca and Urospora penicilliformis) than those with a smoother surface.

 Read more


Lessons Learned

The following lessons were learned from this project:

 Read more




Back to Top

  • No labels