Title: Interfacial Bond between Reinforcing Fibers and Calcium Sulfoaluminate Cements: Fiber Pullout Characteristics

Author(s): Robert B. Jewell, Kamyar C. Mahboub, Thomas L. Robl, and Arne C. Bathke

Publication: Materials Journal

Volume: 112

Issue: 1

Appears on pages(s): 39-48

Keywords: CSA cement; fibers; interfacial bond; low-energy cement; pullout test

DOI: 10.14359/51687234

Date: 1/1/2015

Abstract:
This paper presents the results of an experimental investigation on the influence of the interfacial bond of reinforcing fibers embedded in a calcium sulfoaluminate matrix on the fiber-pullout peak load and energy consumption. Bonding at the fiber-matrix interface plays an important role in controlling the mechanical performance of cementitious composites—in particular, composites formed from sulfate-based systems (calcium sulfoaluminate cements [CSA]), as opposed to the silicate systems found in portland cement. Various types of fibers were selected, including polyvinyl alcohol (PVA), polypropylene, and copper-coated steel. The fibers were embedded in three different matrixes: two sulfate-based cements including one commercially available CSA cement and a CSA fabricated from coal-combustion by-products. The third matrix was a silicatebased ordinary portland cement (OPC). In this study, the results of the single-fiber pullout test were coupled with scanning electron microscopy (SEM) to examine the interfacial bond between the fiber and CSA matrix for evidence of debonding and possible hydration reaction products.