Title:
Steel and Synthetic Fibers as Shear Reinforcement
Author(s):
Victor C. Li, Robert Ward, and Ali M. Hmaza
Publication:
Materials Journal
Volume:
89
Issue:
5
Appears on pages(s):
499-508
Keywords:
mortars (material); reinforced concrete; shear strength; synthetic fibers; tensile properties; Materials Research
DOI:
10.14359/1822
Date:
9/1/1992
Abstract:
The ultimate shear strength of longitudinally reinforced fiber mortar and concrete beams without shear stirrups is examined by testing beams under center-point bending. All beams without fibers failed by diagonal shear cracking. Increases in ultimate shear strength up to 183 percent were recorded due to random reinforcement with volume fractions up to 2 percent of short fibers. In some cases, shear failure was prevented and ultimate failure was in flexure, with yielding of the longitudinal tensile steel. The testing program employed four fiber types (steel, acrylic, aramid, and a high-strength polyethelene); shear span-effective depth ratios a/d ranging from 1.0 to 4.25; reinforcement ratios {rho} of 1.1, 2.2, and 3.3 percent; and beam depths d of 102 and 204 mm. It is shown that correlations exist between the shear strength and a parameter that involves the flexural and splitting tensile strength, the a/d and {rho} ratios, and the beam depth. The relationships suggest simple means of predicting the shear strength of axially reinforced mortar and concrete beams containing fibers. The results are quite versatile for a wide range of fiber types. The work demonstrates that tensile property improvements through fiber reinforcements can be translated into shear capacity improvements.