Bueno M, Haag R, Heeb N, Mikhailenko P, Boesiger L, Poulikakos L D
Empa, Swiss Federal Laboratories for Material Science and Technology, Überlandstrasse 129, 8600 Dübendorf, Switzerland.
Ammann Schweiz AG, Langenthal, Switzerland.
Mater Struct. 2021;54(5):194. doi: 10.1617/s11527-021-01790-y. Epub 2021 Oct 5.
Incorporating crumb rubber (CR) using the dry process, directly in the asphalt mixture rather than into the bituminous binder requires no plant retrofitting, and therefore is the most practical industrial method for CR incorporation into asphalt mixtures. Nevertheless, very few large scale studies have been conducted. This work uses a holistic approach and reports on the functional and environmental performance of asphalt mixtures with different concentrations of CR fabricated employing the dry process in asphalt plants. Gaseous emissions were monitored during the production and laboratory leaching tests simulating the release of pollutants during rain, was conducted to evaluate the toxicology of both the CR material alone and the modified asphalt mixtures. In addition, laboratory compacted samples were tested to assess their fatigue behavior. Furthermore, noise relevant surface properties of large roller compacted slabs were evaluated before and after being subjected to a load simulator (MMLS3) to evaluate their resistance to permanent deformation. The results confirm that comparable performance can be achieved with the incorporation of CR using the dry process for high performance surfaces such as semi-dense asphalt, which usually require the use of polymer modified binders. Environmental performance improvement can be achieved by a washing step of the CR material that could remove polar CR additives which have commonly been used as vulcanization accelerator during rubber production.
采用干法将胶粉（CR）直接掺入沥青混合料而非沥青结合料中，无需对设备进行改造，因此是将胶粉掺入沥青混合料中最实用的工业方法。然而，大规模研究却很少。本研究采用整体方法，报告了在沥青厂采用干法制备的不同CR浓度沥青混合料的功能和环境性能。在生产过程中监测气体排放，并进行实验室浸出试验以模拟降雨期间污染物的释放，从而评估CR材料本身以及改性沥青混合料的毒理学特性。此外，对实验室压实样品进行测试以评估其疲劳性能。此外，在大型滚筒压实板经受荷载模拟器（MMLS3）前后，对其与噪声相关的表面特性进行评估，以评价其抗永久变形能力。结果证实，对于高性能路面（如半密集沥青路面，通常需要使用聚合物改性结合料），采用干法掺入CR可实现相当的性能。通过对CR材料进行清洗步骤，可以去除在橡胶生产过程中通常用作硫化促进剂的极性CR添加剂，从而改善环境性能。
