The thesis explores how plastic residues from Waste Electrical and Electronic Equipment
(WEEE) recycling, which are typically being sent to energy recovery by incineration or destined
for landfills, can be transformed into injectionmolded building components. By focusing
on reinforcement spacers which are located at the internal shearing layer of concrete
introduces a viable application scenario for low-grade, contaminated polymers within the
built environment. The research employs a dual-track methodology: a bottom-up material experimentation track and a top-down product development track with their respective
evaluation parameters that sustain a feedback loop within both tracks throughout the thesis.
The material experimentation track reproduces the key mechanical recycling steps at lab scale
to develop a processable polymer recipe and a heating/cooling cycle for injection molding.
The lab-scale mechanical recycling steps including density separation, colour sorting,
FT-IR and DSC analyses which are replicated to achieve an injection moldable polymer recipe
of carbon black Polypropylene/Polyethylene (PP/PE), Polypropylene, and Polystyrene.
Meanwhile, the product development track iterates material source-specific designs,
which are graded by the parameters in a design optimization tool. The custom multi-criteria
evaluation model guides the selection of the optimal design for the contaminated waste
input. The application scenario confirms the thesis’ structural compatibility and production
feasibility. The thesis proves the processability of rejected plastic fractions into non-exposed
recycled heroes of construction through complex and multi-iterative techniques.