PSI - Issue 67

Available online at www.sciencedirect.com Structural Integrity Procedia 00 (2024) 000–000 Available online at www.sciencedirect.com ScienceDirect

www.elsevier.com/locate/procedia

ScienceDirect

Procedia Structural Integrity 67 (2025) 1–7

International Symposium on Nanotechnology in Construction Materials NICOM8 Graphene Oxide Nanoribbons for High Early-Strength Cement Concrete Shohana Iffat a* , Fabio Matta b , Joseph Meany c , Jay Gaillard d , Mohammed Baalousha e , Mark Elvington f

a Department of Civil Engineering Technology, Farmingdale State College (SUNY), Farmingdale, NY, USA b Department of Civil and Environmental Engineering, University of South Carolina, Columbia, SC, USA c Ionic Flask Materials Group (formerly, Savannah River National Laboratory), Atlanta, GA, USA d Savannah River National Laboratory, Aiken, SC, and University of South Carolina, Columbia, SC, USA e Center for Environmental Nanoscience and Risk, University of South Carolina, Columbia, SC, USA f Private Consultant (formerly, Savannah River National Laboratory), SC, USA

Abstract

Longitudinal oxidative unzipping of the outer walls of multiwalled carbon nanotubes (MWCNTs) yields graphene oxide nanoribbons (GONRs), which exhibit greater open surface area and functional edge content than MWCNTs. This paper presents a study of the nano-amendment of Portland cement concrete with GONRs in concentrations between 0.05% (in weight of cement, wt%) and 0.0005 wt%, thus up to two orders of magnitude lower than that reported as lower-bound in the archival literature. The dispersibility in aqueous solution as a function of GONR concentration and oxygen weight content (O%) was assessed through dynamic light scattering (DLS) and zeta potential analysis. The results indicated that less effective suspensions were obtained for 0.05 wt% of GONRs and 22.7 O%. Therefore, GONR water suspensions with 30-40% O% were used to manufacture 50 mm × 100 mm cylindrical concrete specimens. After 7 days of curing, results from uniaxial compression tests using four specimens per configuration (MWCNT concentration and O%) showed that the incorporation of GONRs resulted in an average increase in compressive strength up to 45%. Consistent with the DLS and compression test results, SEM micrographs showed well-dispersed GONRs together with accelerated and preferential formation of calcium silicate hydrates (C-S-H) for all GONR concentrations. The results indicate, for the first time, that the incorporation of very small concentrations (as low as 0.0005 wt%) of well-dispersed GONR amendments can significantly enhance the early-age concrete strength. However, such enhancement became insignificant after 28 days of curing. © 2024 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of NICOM8 Chairpersons © 2024 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of NICOM8 Chairpersons

* Corresponding author. Tel.: +1-934-420-5620; E-mail address: iffats@farmingdale.edu.

2452-3216 © 2024 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of NICOM8 Chairpersons

2452-3216 © 2024 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of NICOM8 Chairpersons 10.1016/j.prostr.2025.06.001