Study on the Performance of the Physical Foaming Warm-mix Recycled Asphalt Mixture Zheng Zhigang, He Yunwu, Wang Tao, Wei Hanxin, Liang Xiayi, Xiao Xin and Liu Tao E3S Web Conf., 261 (2021) 02058 Published online: 21 May 2021 DOI: 10.1051/e3sconf/202126102058