An experimental and numerical study on the age depended bond-slip behavior between nano-silica modified carbon fibers and cementitious matrices

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

Abstract

Electrophoretic deposition of nano-silica on the surfaces of carbon fibers (CF) is a novel approach for modifying the interfacial bond properties between the fibers and cementitious matrices. To understand its pullout behavior with increasing age, single fiber pullout tests and scanning electron microscopy were performed at various curing times for pristine and modified fibers. In this article, a new approach for calculating the debonding energy is introduced and two theoretical models – a stress-controlled and an energy-controlled – were employed to obtain the critical interface failure criterion. The results showed that interfacial adhesion at fiber-matrix interface was increasingly improved with age compared to the untreated fiber, due to the formation of C–S–H gel in the vicinity of the fiber surface. Meanwhile, the untreated fibers exhibited only a slightly increasing trend of interfacial bonding with longer curing time. A finite element model was applied to simulate the fiber pullout failure, which incorporated a discrete cohesive concept into the smeared phase-field method in a Representative Crack Element (RCE) framework. Using a phenomenologically defined cohesive traction-separation law, the numerical simulations successfully captured the characteristics of the experimental pullout curves. According to proper parametric calibrations, good agreement was obtained between the numerical results and the respective experimental evaluations.

Details

Original languageEnglish
Article number104416
JournalCement and Concrete Composites
Volume128
Publication statusPublished - 1 Apr 2022
Peer-reviewedYes

External IDs

unpaywall 10.1016/j.cemconcomp.2022.104416
Mendeley aa61fd54-a498-3554-96a8-9966aca3c193

Keywords

Research priority areas of TU Dresden

DFG Classification of Subject Areas according to Review Boards

Keywords

  • Bond strength, Carbon fiber, Cement-based composites, Coating, Finite element model, Nano-silica, Pullout test, Surface modification

Library keywords