**7.1 Retaining walls**

EoL composites profiles were manufactured for retaining walls near the Beatrix lock-gate in Almere, The Netherlands [3, 14]. 80 separate profiles, each with a length of 3.5 metres were produced using two steel moulds. The cross-sectional

**Figure 9.** *Cross section of profile for retaining wall built up with a core of EoL composite [3].*

**Figure 10.** *Production of profiles using EoL composite by vacuum infusion under foil [3].*

dimensions of the profiles were 40 x 250 mm with a tongue-and-groove detailing. A drawing of the cross-section of the profile is given in **Figure 9**.

The profile has an effective width of 250 mm and a thickness of 40 mm. The outside skin is build up from a virgin glass reinforced polyester laminate containing a 900 g/m2 random reinforcement (glass mat, green in the picture) and a 900 g/m<sup>2</sup> UD-reinforcement of 200 mm width on both sides (blue in the picture). The core is formed by re-used EoL thermoset flakes that are bound by a polyester resin.

For this demonstrator, the profiles were made by means of vacuum infusion under foil in steel moulds. Into the mould, the glass injection mat was charged (Polymat HI-FLOW M03P Core, Scott & Fyfe, 900 g/m<sup>2</sup> ) along with the first layer of 200 mm wide UD-glass reinforcement (UNIE840, Selcom 840 g/m2 ) on which the EoL flakes and strips were applied. On top of this, a second layer of UD-reinforcement was placed and the glass injection mat was closed around it. Then the vacuum foil was applied. A brown pigmented polyester DCPD resin (Synolite 1967-G-6 of AOC) was injected, giving the profile a wood-like appearance. **Figure 10** shows the charging of the mould with strips and flakes of EoL composite (left) and the product that is infused with brown pigmented resin (right).

**Figure 11.** *Installation of retaining wall by vibrating profiles with EoL composite in the soil [3].*

**Figure 12.** *Guiding structure with two lowest rows of beams made from EoL composite [3].*

The profiles were tested mechanically and the same bending strength was found as for the same profile geometry made of azobé wood, that are commonly used for these applications. The profiles were installed in 2017 by vibrating into the ground without any damage being incurred on the profiles, see **Figure 11**. Inspections and tests on profiles withdrawn from the ground in 2019, two years after installation, showed no signs of degradation nor loss of strength.
