Effect of waste latex paint on concrete

Approximately 20% of paint sold in western countries does not get used for its intended purpose, and in time much of this left-over paint ends up in land-fill as part of the household waste collection, at a significant economic and environmental cost. In New Zealand, a comprehensive product stewardship campaign has been initiated to recover waste paint before it enters the waste stream, while the collaboration amongst a cohort of companies has contributed to utilising waste latex paint in concrete. The objective of this study was to investigate the effects of waste latex paint on concrete, with special focus on a low strength standard 20 MPa concrete mix. It is demonstrated that waste latex paint can improve the workability and durability of concrete, whilst achieving sufficient compressive strength. Phase analysis indicated that the addition of waste latex paint does not affect the concrete hydrates. It was established that concrete with 12 L/m3 of waste latex paint is suitable for use in low strength non-structural concrete.