Studying the possibility of producing self-colored plaster of Paris (POP) as an alternative to traditional paints

This study was conducted in order to examine the production of Plaster of Paris (POP) in green and red colors. For this purpose, green and red pigments were prepared based on iron oxide and chromium oxide, respectively. To investigate the effect of pigments addition, the iron oxide and chromium oxide were added in four percentages by weight (0%, 2%, 4% and 6%). The colored POP mixes were investigated under mechanical and physical tests at the age of 28 days. These tests included plaster compressive strength, flexural strength and hardness of plaster. Also, the standard consistency test and the expansion test were conducted for the POP mixes. Based on the experimental results, it has been found that the 2% of pigments addition showed the best volumetric soundness over other ratios of additions. Moreover, The experimental program of the current study revealed that the coloring process has no any detrimental effect on the fresh and the hardened properties of the POP mixes.