Today, the idea of functionally graded material (FGM), which refers to using different materials in multiple layers to improve overall system performance, is commonly used in various engineering sciences. The present study investigates the fracture behavior (modes I and III) of the functionally graded concrete pavement (FGCP) when the bottom layer is RCC (roller compacted concrete) and the top one is ordinary PCC (Portland cement concrete) or FPCC (fibrous Portland cement concrete). Results have shown that the FGC specimens’ flexural strength is similar to that of the full-depth ones and adding polypropylene fibers does not improve it; the main fiber effect is related to the specimens’ post-cracking behavior. While adding fibers highly improves the mode I fracture energy, its effect on mode III fracture toughness is negligible. The pull-off test results have also shown that more than 2 h time lag in pouring two layers will result cold joints between two layers.

今天，功能梯度材料 (FGM) 的想法是指在多层中使用不同的材料以提高整体系统性能，已广泛用于各种工程科学。本研究调查了底层为 RCC（碾压混凝土）而顶层为普通 PCC（波特兰水泥混凝土）或 FPCC（纤维波特兰）时功能级配混凝土路面（FGCP）的断裂行为（模式 I 和 III）。水泥混凝土）。结果表明，FGC试样的抗弯强度与全深度试样的抗弯强度相似，加入聚丙烯纤维并没有提高；主要的纤维效应与试样的开裂后行为有关。虽然添加纤维极大地提高了 I 型断裂能，但其对 III 型断裂韧性的影响可以忽略不计。