Recycled brick powder from construction and demolition waste as waterborne coating filler with robust scrubbing resistance

Abstract

During the daily use of waterborne coatings, it was unavoidable to be scratched so that it was required to have the property of scrubbing resistance. This study explored the use of recycled red bricks as a substitute filler for waterborne coatings. The prepared red brick powder (RBP) waterborne coating exhibited exceptional scrubbing resistance, with a maximum resistance of over 9000 times, which was approximately 4.5 times higher than the national standard in China. The addition of pigment volume concentration (PVC) between 40 ∼ 53% significantly improved the coating’s performance. The use of RBP as a coating framework also enhanced the coating’s hardness, which was found to be 85–103 times better than that of commercial coatings (75–90 times). Moreover, the water absorption of RBP waterborne coating was only 14.4%, which is significantly lower than that of commercial coatings (25.2–32.0%). These two key factors, low water absorption and high hardness, were found to be crucial in improving the scrubbing resistance of coatings. The incorporation of emulsion, such as styrene acrylic, further improved the compactness of coating, by strengthening the benefits of the good hardness and low water absorption. The use of construction and demolition waste as a resource for waterborne coating would be a green and efficient way to eliminate massive land resource occupation and potential environmental risks.