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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.

This research aims to observe the effect of applying cellulose fibre to the mechanical properties of bituminous mixtures when subjected to various loading speeds that simulate various traffic situations with fibre dosages of 0.3 – 0.5% of mix weight. The semi-circular bending (SCB) test was employed in this project, where the specimens were subjected to loading speeds of 0.25, 0.5, and 1 mm/min. The incorporation of cellulose was reported to enhance the tensile strength of the specimens up to 43.75% at the lowest loading rate and 13.75% at the highest rate, while the critical strain energy was elevated to 24.54% at the lowest rate and 38.2% at the highest rate, signifying better resistance against loading. Meanwhile, the flexibility index (FI) of modified specimens showed a mixed trend compared to the control mix, 30.43% higher at the lowest rate and 28.9% lower at the highest rate. To sum up, the incorporation of cellulose fibre into the bituminous mixture can enhance its strength and resistance against various loading rates, and the fibre dosage of 0.3% is recommended to give the best outcome.