Shear-bond behavior of nanocellulose-modified SHCC composite slabs: Translating material-level capacity into improved structural performance

Abstract

Owing to their exceptional tensile properties, strain-hardening cementitious composites (SHCC) are indispensable for building and maintaining sustainable and resilient civil infrastructure. As such, to propel the structural implementation of SHCC, it is critical that their intriguing tensile characteristics be effectively translated into improved structural performance. Herein, we capitalize on the intrinsic pseudo-ductility of a novel SHCC—incorporating nanocellulose fibers and post-consumption glass powder (hereafter referred to as “nSHCC-GP”)—to mitigate shear-bond failure caused by the relative slip between steel and concrete in composite deck slabs. Twelve full-scale composite deck slabs, six with conventional high-performance concrete (HPC) incorporating steel mesh and six steel-mesh-free nSHCC-GP slabs, were subjected to monotonic bending. With the concrete for both slab sets designed for similar compressive strengths, the influence of concrete type (HPC or nSHCC-GP), decking profile (trapezoidal or reentrant), and shear span (520–770 mm) on the flexural capacity and shear-bond resistance was examined. The use of nSHCC-GP as a concrete topping improved the flexural capacity of composite slabs by >50 % and the shear-bond resistance by up to 40 %. Thus, the strain-hardening characteristics of nSHCC-GP were effectively translated into the structural scale, providing steel-mesh-free, high-performance composite deck slabs.