Title: Structural Behavior of Low-Carbon and Functionally Graded Concrete One-Way Slab Strips

Author(s): Jacob Yager, Joshua Woods, Evan C. Bentz, and Neil A. Hoult

Publication: Structural Journal

Volume: 121

Issue: 4

Appears on pages(s): 149-159

Keywords: digital image correlation; distributed fiber-optic sensing; functionally graded concrete; low-carbon concrete; one-way slabs; supplementary cementitious materials (SCMs)

DOI: 10.14359/51740715

Date: 7/1/2024

Abstract:
Supplementary cementitious materials (SCMs) have been used to replace portland cement and are used in conjunction with advanced mixture design approaches in reinforced concrete for the purpose of creating low-carbon concrete (LCC). In this research, functionally graded concrete (FGC) was used with LCC to provide strength and serviceability for reinforced concrete one-way slab strips by placing a higher-strength/stiffness concrete in the flexural compression region and LCC in all other locations. The behavior of FGC slab strips with varied connection types, placement methods, reinforcement ratios, and ages were compared to uniform specimens with different types of LCC and conventional concrete. Behavior was evaluated through load deflection, cracking, and strains during four-point bending, which were measured using distributed sensing, including distributed fiber-optic sensing and digital image correlation. Limited differences in behavior existed among specimens with the same reinforcement ratios. However, some FGC specimens had higher stiffness and ultimate capacity. Implications of FGC, including cracking behavior at the interface, are also discussed.