The interfacial transition zone (ITZ) between the aggregates and cementitious paste is generally a weak spot in concrete. To address this deficiency, the graphene nanoplatelets (GNP) are adopted and a novel approach is proposed in this study. Initially, GNP with three different diameters of 2 μm, 4 μm and 7 μm are evaluated. The 2 μm GNP are selected for the best strength and microstructure improvement in cementitious composites. Subsequently, the concrete made of GNP-precoated aggregate is prepared. The SEM and EDS are used to evaluate the microstructure and elementary composition of its ITZ. This research demonstrates that GNP-precoated aggregate approach significantly improves the efficacy of GNP in concrete by enhancing the ITZ. GNP promote the formation of calcium silicate hydrate (C–S–H) while concurrently mitigating the production of calcium hydroxide (CH) in ITZ, leading to enhanced elemental distribution and compactness of ITZ, as well as a reduced ITZ thickness. The proposed method notably enhances the mechanical properties of concrete.

中文翻译：

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通过在界面过渡区 (ITZ) 富集石墨烯纳米片 (GNP) 来提高混凝土的机械性能

骨料和水泥浆之间的界面过渡区 (ITZ) 通常是混凝土的薄弱环节。为了解决这一缺陷，本研究采用了石墨烯纳米片（GNP）并提出了一种新方法。首先，评估具有2μm、4μm和7μm三种不同直径的GNP。选择 2 μm GNP 是为了在水泥基复合材料中实现最佳的强度和微观结构改善。随后，制备由GNP预涂骨料制成的混凝土。 SEM和EDS用于评估其ITZ的微观结构和元素组成。这项研究表明，GNP 预涂骨料方法通过增强 ITZ 显着提高了 GNP 在混凝土中的功效。 GNP 促进硅酸钙水合物 (C–S–H) 的形成，同时减少 ITZ 中氢氧化钙 (CH) 的产生，从而增强 ITZ 的元素分布和致密性，并减少 ITZ 的厚度。所提出的方法显着提高了混凝土的力学性能。