Title: Mechanical Properties of Hybrid Cement-Based Composites

Author(s): Barzin Mobasher and Cheng Yu Li

Publication: Materials Journal

Volume: 93

Issue: 3

Appears on pages(s): 284-292

Keywords: cement-based composites; concretes; cracking; fiber rein-forced concrete; fibers; flexure; fracture; hybrid composites; mechanical testing; mortar; R-curves; tensile stress; toughness.

DOI: 10.14359/9813

Date: 5/1/1996

Abstract:
Tensile and jexural properties of cementitious composites reinforced with carbon and alumina whiskers are studied, in addition to polypropylene (PP) jbers. Signijcant strength increase is observed by the addition of short carbon and alumina whiskers. Due to the inability to bridge the macrocracks, the whisker 's contribution is limited to increasing the ultimate strength and marginal postpeak toughening. Fracture toughness may be increased by the addition of PP fibers to produce hybrid composites. Pullout of PP jbers from the matrix is the main reinforcing mechanism and results in signijcant energy dissipation. Hybrid composites are shown to have superior strength and toughness properties due to the interaction of reinforcing jbers. Various procedures to characterize the tensile and flexural fracture of these composites are evaluated. A method to obtain the experimental R-curves is discussed. This approach provides the most suitable means of characterizing the fracture response of FRC materials.