Field implementation of cellulose nanocrystals (CNC) in concrete pavement test track

ABSTRACT

This pilot study aimed to fill the knowledge gap on incorporating cellulose nanocrystals (CNC) in concrete pavements in real-world construction settings. The constructability of CNC concrete was evaluated, and the fresh and hardened properties were fully characterised. A series of concrete slabs were placed using ordinary portland cement concrete (OPC mix), portland limestone cement concrete (PLC mix), and PLC-concrete with CNC at a dosage of 0.10% wt. of cementitious materials (CNC mix). CNC and PLC mix showed no significant differences in consistency, workability, and other fresh properties. The addition of CNC did not show significant changes in cumulative heat over PLC. CNC did not lead to notable changes in compressive and flexural strength, modulus of elasticity, coefficient of thermal expansion (CTE), and electrical resistivity. However, the CNC mix had a notably 9% lower drying shrinkage strain at seven months than the PLC mix. The PLC mix exhibited the lowest water absorption rate, while CNC did not induce significant changes. Overall, this study highlights the constructability of concrete slabs with CNC, with notable contributions of CNC to reducing long-term drying shrinkage.

KEYWORDS:

• Portland limestone cement
• cellulose nanocrystals
• field constructability
• mechanical properties
• water penetrability

Acknowledgments

The study was performed as part of a sub-award contract with Organ State University’s award by the Joint Institute for Wood Product Innovation – contributions of Drs. Jason Wiess and Burkan Isgor, during the concentration and dispersion study and obtaining the CNC sample and trial batches of CNC concrete, are greatly acknowledged. Cemex, and Mr. Mark Hill in particular, for supplying ready-mix concrete for the test track, cooperation with the research team, and facilitating the specific requirements of the research project are greatly acknowledged. Forest Product Laboratory is thanked for supplying cellulose nanocrystals (CNC). The UCPRC staff and students, including Jeffrey Buscheck, Julio Paniagua, Mauricio Melgar, Michael Bowman, and Madelin Barry, are acknowledged for their work on the test track construction.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by Joint Institute for Wood Product Innovation.