Lab-scale environmental impact measurement of polymer-modified asphalt concrete mixtures production

Abstract

This study aims to evaluate and compare the environmental impact of producing numerous polymer-modified asphalt concrete mixture types for road structures at the laboratory scale measured by air quality monitoring devices in a designed isolated area. Several mixture combinations were examined in this study, namely between the production of the standard hot mix at 160oC (case 1) and polymer-modified warm mix asphalt with 5% and 6% polymer dosages at 130oC (case 2 and case 3), as well as the production of hot mix asphalt using polymer modification by wet mix - known as polymer modified binder/PMB at 180oC (case 4) and dry mix methods using 5% and 6% polymer dosages at 160oC (case 5 and case 6), with each case represented by five samples fabrication. Case 4 yields the highest carbon dioxide, the volatile organic compound (VOC), formaldehyde (HCHO), and particulate matter (PM10 and PM1) by a total of 8195ppm, 10.12ppm, 6.5ppm, 1643 µg/m3, and 838 µg/m3, respectively, except PM2.5, where the outcome of case 3 is 1.2% higher than case 4. Meanwhile, the lowest emissions are recorded for case 2 and case 5, with the ratio to case 4 ranging from 43.5% to 96.5%. The heating phase generally gives the highest contribution to the total result, with the proportion ranging from 43.5% for carbon dioxide to above 90% for particulate matter. To sum up, producing hot mix asphalt with PMB and the mixer blending stage generates the highest emission.