In this study, four different additives (Styrene–butadiene–styrene (SBS), Trinidad Lake Asphalt (TLA), Iranian Gilsonite (IG) and American Gilsonite (AG)) were used in bitumen modification. The rheological properties of bitumen were improved with the additive usage, and the desired performance grade (PG 70-34) was achieved by using additives in pure bitumen (PG 58-34) at the indicated ratios. Wheel tracking tests and semi-circular bending tests were applied for hot mix asphalt (HMA) samples. The main results showed that all the additives increased resistance to permanent deformation of HMAs, and that TLA was the most effective additive. In addition, it was found from the semi-circular bending tests that deformation values of mixtures prepared with modified bitumens and subjected to long-term ageing decreased. As a result, long-term aged and modified bitumen mixtures exhibited more brittle behaviour. The increase in maximum load values led to an increase in the area under the load-strain curves. Thus, crack propagation resistance of mixtures prepared with modified binders was increased.

在这项研究中，使用了四种不同的添加剂（苯乙烯-丁二烯-苯乙烯（SBS），特立尼达湖沥青（TLA），伊朗吉利石（IG）和美国吉利石（AG））进行沥青改性。沥青的流变性质随添加剂的使用而改善，通过在指定比例的纯沥青（PG 58-34）中使用添加剂，可以达到所需的性能等级（PG 70-34）。车轮跟踪测试和半圆形弯曲测试适用于热混合沥青（HMA）样品。主要结果表明，所有添加剂均增加了对HMAs永久变形的抵抗力，而TLA是最有效的添加剂。另外，从半圆形弯曲试验发现，用改性沥青制备并经受长期老化的混合物的变形值降低。结果是，长期老化和改性沥青混合物表现出更多的脆性。最大负荷值的增加导致负荷-应变曲线下面积的增加。因此，提高了用改性粘合剂制备的混合物的抗裂纹扩展性。