Potential of Tin Slag-containing Aggregates as Road Pavement Material

다국어 초록 (Multilingual Abstract)

Tin slag is a byproduct obtained from the tin smelting industry and contained naturally occurring radioactive material (NORM); therefore, it has to be managed accordingly. This study focuses on recycling the waste in exchange for natural aggregates for road pavement due to the potential features as construction materials. The main objective of this study is to analyze the use of tin slag by diluting its radioactivity level and as the replacement of natural aggregates while focusing on identifying the mechanical properties of the mixture. Tin slag was used as coarse aggregate in the range of 0–85% while the percentage of recycle glass was maintained at 15% and granite rocks in range of 0–100%. In this research, the concentration activity of NORM in tin slag have been measured using a gamma ray spectrometer. Few laboratory tests for the final product are carried out such as Los Angeles abrasion value (LAAV), aggregate crushing value (ACV), and aggregate impact value (AIV). This study was also conducted to analyze the leachability of As, Cd, Ba, Cr, Pb, Se and Ag from the different composition. From the measurement result, the average concentration of 226Ra, 232Th and 40K are 318.21 Bq·kg?1, 602.07 Bq·kg?1 and 89.84 Bq·kg?1, respectively. The outdoor dose rates were found to be lower than 1.5 mSv·yr?1 in sample A1, A2 and A3 which is the recommended limit for construction materials. The sample toxicity was assessed using the toxicity characteristic leaching procedure (TCLP) and the concentration of the elements studied was analysed using ICP-MS. The result from the analysis indicated that the concentrations of the heavy metal elements were between 0.001–26.94 mg·kg?1, which is lower than the limit for each element. As a conclusion, addition of tin slag between 5 to 25% in exchange of granite rocks as road pavement have showed potential evidence in the test for construction material. Besides, it has low leachability to the environment while diluting the radioactivity level.