PHYSICAL AND MECHANICAL PROPERTIES OF SOME PLASTER MORTARS WITH OXIDE WASTES

The present study evaluates the characteristics and performances of plaster mortars for construction, with the addition of oxide waste resulted from the filling of metal statues. Several plaster mortars using 0 %, 5 %, 10 %, 15 % and 20 % wt. of waste in composition were prepared in the laboratory and the physical and mechanical characteristics were determined. The waste oxide composition is mainly formed of 61.26 % SiO2, 11.20 % Al2O3 and 23.50 % CaSO4. The consistency water is about 75 % for mortars without waste. With increasing the waste content in the mortar composition, the amount of water decreases at about 50 %. It was also determined the setting time for all plaster mortars without any setting time retarder. The initial setting time for the control mortar was 12 minutes and with increasing the waste percentage in the composition, the setting time increased proportionally, reaching 18 minutes for the sample with 20 % wt. waste. The flexural strength of 2.03 N/mm(2) and compressive strength of 10.31 N/mm(2) were obtained for the sample with the highest amount of waste (20 % wt.).