Using graphene oxide to improve the properties of ultra-high-performance concrete with fine recycled aggregate. (30th October 2020)

• Record Type: Journal Article
• Authors: Yu, Lanzhen; Wu, Rongxing
• Is Part Of: Construction & building materials. Volume 259(2020)
• Publication Date: 2020-10-30
• Subjects: Ultra-high-performance concrete -- Graphene oxide -- Volume stability -- Mechanical properties -- Durability -- Recycled aggregates; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2020.120657
• Languages: English
• ISSNs: 0950-0618

Abstract

Highlights: UHPC designed in the work has good mechanical properties, volume stability, and durability. Mechanical properties of UHPC are significantly improved by adding GO. Durability properties of UHPC are effectively enhanced by adding GO. Pore structure of UHPC is refined by adding GO. Optimal amount of GO is 0.06 wt% in UHPC produced in the paper. Abstract: One of the most efficient methods for recycling construction and demolition (C&D) waste is to utilise the recycled aggregate (RA) obtained from the C&D waste to manufacture recycled aggregate concrete. However, the properties of the recycled aggregate concrete are inferior compared to normal concrete, owing to the use of the RA. Accordingly, this study examines the use of graphene oxide (GO) to enhance the properties of ultra-high-performance concrete (UHPC) with fine RA. An initial mixture of UHPC with fine RA was designed based on a modified Andreasen & Andersen particle packing model, and the effects of different contents of GO on the mechanical properties, volume stability, and durability of UHPC with fine RA were investigated. It was found that (1) the mechanical properties, volume stability, and durability properties of UHPC with fine RA were comparable to or even better than those of UHPC with natural river sand; (2) the optimal amount of GO was 0.06 wt%, considering the mechanical properties, durability properties, and pore structure of the UHPC; (3) the compressive strength, tensile strength, flexural strength, and elastic modulus of UHPC increased by 2.04%–16.04%, 7.36%–30.50%, 5.83%–23.40%, and 3.62%–12.95%, respectively, owing to the addition of GO; and (4) both the chloride penetration resistance and the freezing and thawing resistance of UHPC effectively improved owing to the addition of GO. These findings are conducive to the recycling of C&D waste.