Abstract

This article presents the results of a preliminary research to explore the feasibility of using graphene to improve mechanical properties of recycled aggregate concrete (RAC). Graphene of different nominal flake sizes (5, 10 and 20 μm) and concentrations of 0.01%, 0.02%, 0.05% and 0.1% of the combined weight of cement and sand were incorporated into RAC with and without crumb rubber. The results indicate that there was no improvement in mechanical properties of recycled aggregates (RAs) concrete with crumb rubber. Also, if aggregates were not washed, even without any crumb rubber, adding graphene was not effective in improving mechanical properties of RAC due to excessive dust of unwashed RAs. However, the results reveal that by agitating RAs in water to remove excessive dust, adding small amount of graphene improves the mechanical properties of RAC. By adding 0.01% graphene flakes, the average compressive and splitting tensile strengths of RAC were increased from those of RAC without graphene by 43.9% and 24.1% to 39.14 and 3.76 MPa, respectively, which are comparable to those of concrete using natural aggregates (NAs). However, using more graphene flakes did not result in any further improvement.

摘要

本文介绍了初步研究的结果，以探索使用石墨烯提高再生骨料混凝土 (RAC) 力学性能的可行性。不同标称薄片尺寸（5、10 和 20 μm）的石墨烯和浓度分别为水泥和沙子总重量的 0.01%、0.02%、0.05% 和 0.1% 的石墨烯被掺入有和没有橡胶粒的 RAC 中。结果表明，再生骨料 (RAs) 混凝土的力学性能没有得到改善。此外，如果骨料未清洗，即使没有任何橡胶粉，添加石墨烯也不能有效改善 RAC 的机械性能，因为未清洗的 RA 灰尘过多。然而，结果表明，通过在水中搅动 RAs 以去除过多的灰尘，添加少量石墨烯可改善 RAC 的机械性能。通过添加 0.01% 的石墨烯薄片，RAC 的平均抗压强度和劈裂抗拉强度分别比不含石墨烯的 RAC 提高 43.9% 和 24.1%，达到 39.14 和 3.76 MPa，与使用天然骨料的混凝土（NAs）相当). 然而，使用更多的石墨烯薄片并没有带来任何进一步的改善。