Abstract:
Waste paint (WP) has the potential to become a serious environmental burden in the future with very limited safe disposal options. One potential avenue for the disposal and consolidation of this waste is by stabilizing it in concrete pavement tiles and if deemed viable, such application can be practiced in a large scale in the country's concrete walkway making industry. In this study, experiments were made to assess the effects of WP on the mechanical properties of tiles if it is incorporated in different proportions (10%, 20%, 30%, 40% and 50%) by weight as partial replacement for mixing water. The objective was to explore the viability of waste paint as a concrete walk tile constituent and determine the effectiveness of such tile as a safe option for waste paint stabilization. Test results indicate that the compressive strength of tiles incorporating 20-50% WP decreases which iseither due to the retarding effects of paints or the increase ofvoid spaces in tiles as a foaming effect of paints. On the other hand, tiles incorporating 10% of waste paint develops a better strength than that of the reference mixture at the age of 28 days. However, a general increase in the compressive strength of all tiles was observed with curing time which is due to the polymer film formation of the hardened concrete. The water absorption of tiles in general decreaseswith the increase of waste paint proportion when compared with the reference mixture which is also due to the formation of polymer film which makes the concrete water tight. The test further indicates that tiles produced with the use of hydraulic pressing machine shows an overall improvement both in terms of compressive strength and water absorption than tiles produced under laboratory conditions. This is due to the pressure applied from the pressing machine which make tiles highly compacted. Also by valorizing WP in concrete, there is a possibility to save water & reduce CO2 and energy by reduction in the amount of virgin polymers required for PMC. Therefore, tiles incorporating a specified proportion of WP have been found to meet ASTM C902 requirements for building construction material. Results from this study indicate that waste paint can be sustainably stabilized in concrete walk tiles and large-scale application of this technique can be envisaged for Ethiopia where both the paint and tile industries continue to be important economic pillars of the country.