Application Of High GTR Percentage Asphalt Rubber in Perpetual Pavement: Expressway Projects Experience of Xiong’an, China

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Application Of High GTR Percentage Asphalt Rubber in Perpetual Pavement: Expressway Projects Experience of Xiong’an, China

Guoqing Wang, Lusheng Qin, Xinqiang Wang, Xiaoxiao Yang, Bin Xu

ABSTRACT. Suitable structural design, proper materials selection, and excellent construction practices, play vital roles in perpetual pavement performance. Based the benefits of asphalt rubber in fatigue resistance，low temperature cracking，and rutting resistance，long-life semi-rigid pavement structure was constructed in Xiong’an ,China. The total length of expressway is 73 km，in which 60,000 tons of rubber asphalt was used, equivalent to 26,000 tons of waste tire rubber powder. The perpetual pavement was 24 cm of asphalt rubber over 60 cm of cement treated aggregate base. The asphalt rubber were divided into three layers. In the wearing course, the content (mass fraction) of ground tire rubber (GTR) is 30%. In the middle layer, the content of GTR is 40%. In the base course, the content of GTR is 50%. In order to verify the performance of asphalt rubber，the hot mixes was evaluated through laboratory tests for fatigue life, permanent deformation and indirect tensile strength. The results showed that asphalt-rubber hot mixes presented a higher resistance to rutting, cracking, and fatigue damage. Additionally, The field performance (flatness, compactness, etc.) of high content rubber asphalt permanent pavement is better than that of conventional hot mix asphalt pavement, and could meet the corresponding standard requirements. Therefore, the results are helpful to the popularization application of high dosage rubber powder and permanent pavement in China.

KEYWORDS: Ground tire rubber, High content rubber asphalt, Perpetual pavement, Expressway project.