Spadoni Sara, Ingrassia Lorenzo Paolo, Paoloni Giulio, Virgili Amedeo, Canestrari Francesco
Department of Civil and Building Engineering and Architecture (DICEA), Università Politecnica delle Marche, Via Brecce Bianche, 60131 Ancona, Italy.
Autostrade per l'Italia, Via A. Bergamini 50, 00159 Roma, Italy.
Materials (Basel). 2021 Sep 15;14(18):5310. doi: 10.3390/ma14185310.
The application of geocomposites as reinforcement in asphalt pavements is a promising solution for the maintenance/rehabilitation of existing pavements and for the construction of new pavements, whose effectiveness strongly depends on the physical and mechanical properties of the geocomposite. This study aims at assessing the influence of four different geocomposites, obtained by combining a reinforcing geosynthetic with a bituminous membrane, on the crack propagation and interlayer bonding of asphalt pavements. First, a laboratory investigation was carried out on double-layered asphalt specimens. The crack propagation resistance under static and dynamic loads was investigated through three-point bending tests (carried out on specimens with and without notch) and reflective cracking tests respectively, whereas the interlayer shear strength was evaluated through Leutner tests. Then, a trial section was constructed along an Italian motorway and a Falling Weight Deflectometer (FWD) testing campaign was carried out. The laboratory investigation highlighted that-as compared to the unreinforced system-the geocomposites increased the crack propagation energy in the layer above the reinforcement from five to ten times, indicating that they can significantly extend the service life of the pavement by delaying bottom-up and reflective cracking. However, they also worsened the interlayer bonding between the asphalt layers (de-bonding effect). The field investigation indicated that all geocomposites decreased the stiffness of the asphalt layers with respect to the unreinforced pavement as a consequence of the de-bonding effect, thus corroborating the laboratory results. Based on the results obtained, it is desirable that the geocomposite possess a high energy dissipation capability and an upper coating ensuring good adhesion between the asphalt layers. The monitoring of the existing trial section in the future will provide useful data on the long-term field performance of reinforced pavements subjected to actual motorway traffic.
土工合成材料在沥青路面中作为增强材料的应用，对于既有路面的养护/修复以及新建路面的施工而言，是一种很有前景的解决方案，其有效性在很大程度上取决于土工合成材料的物理和力学性能。本研究旨在评估通过将增强土工合成材料与沥青膜相结合而获得的四种不同土工合成材料，对沥青路面裂缝扩展和层间粘结的影响。首先，对双层沥青试件进行了室内研究。分别通过三点弯曲试验（在有切口和无切口的试件上进行）和反射裂缝试验研究了静载和动载下的抗裂缝扩展性能，而通过勒特纳试验评估了层间抗剪强度。然后，沿着一条意大利高速公路修建了一个试验路段，并开展了落锤式弯沉仪（FWD）测试活动。室内研究表明，与未增强体系相比，土工合成材料使增强层上方层中的裂缝扩展能量提高了五到十倍，这表明它们可以通过延迟自下而上的裂缝和反射裂缝来显著延长路面的使用寿命。然而，它们也恶化了沥青层之间的层间粘结（脱粘效应）。现场调查表明，由于脱粘效应，所有土工合成材料相对于未增强路面都降低了沥青层的刚度，从而证实了室内研究结果。基于所获得的结果，期望土工合成材料具有高能量耗散能力以及确保沥青层之间良好粘结的上层涂层。未来对现有试验路段的监测将为承受实际高速公路交通的增强路面的长期现场性能提供有用数据。
