再生沥青混合料性能研究

Study on Properties of Recycled Asphalt Mixture

该文通过再生沥青混合料和再生沥青的复合模量,探讨旧沥青混合料掺量对混合料以及再生沥青的影响。对于PG 64-22级沥青,考虑了15%,25%,40%三个旧料掺量水平;对于PG58-28,考虑了25%和40%两个旧料掺量水平;同时以PG64-22沥青,不添加旧料作为对照组。成型后的混合料试件在三个不同的温度下进行测试以确定其复合动态模量(|E*|)。同时分别在相同的温度下对抽提后的再生沥青,抽提后新沥青以及新沥青进行复合剪切模量测试(|G*|)。对混合料试件进行了低温蠕变和间接拉伸试验,以确定其低温蠕变柔量和间接拉伸强度,以用来预估路面的临界开裂温度。统计分析结果表明,旧料掺量为15%和25%时,其平均强度和动态模量没有显著差别。只有当温度较高时,对照组和旧料掺量为40%的混合料间存在一些差异。

With the composite modulus of recycled asphalt mixture and recycled asphalt, the impact of mixing amount of old asphalt on recycled asphalt is discussed. To PG 64-22 asphalt, the three mixing amount levels of 15% ,25% and 40% are taken into consideration; to PG58-28 asphalt, the two old mixing amount levels of 25% and 40% are considered; and PG64-22 asphalt with no old mixing for comparison. The finished mixing materials are tested under three different temperatures to determine its composite dynamic modulus （[E＊[）. Meanwhile, recycled asphalt extracted under the same temperature and the new asphalt are applied to do composite shear modulus test （[G＊I）. Low temperature creep and indirect tensile test are done to mixture test pieces; so that the temperature creep compliance and indirect tensile strength are determined to estimate the critical cracking temperature of the road. The analy- sis results show that there are no obvious differences in average strength and dynamic modulus when the old mixing amotmt is at 15% and 25%, but there are some differences when at 40% with higher temperature.