International Concrete Abstracts Portal

Title: Properties of Fiber Reinforced High-Strength Semi-Lightweight Concrete

Author(s): P. Balaguru and Michael G. Dipsia

Publication: Materials Journal

Volume: 90

Issue: 5

Appears on pages(s): 399-405

Keywords: compressive strength; expanded shale concretes; volume change; fiber reinforced concretes; flexural strength; lightweight concretes; modulus of elasticity; shear properties; silica fume; tension; water-reducing agents; Materials Research

Date: 9/1/1993

Abstract:
The results of an experimental investigation of the behavior of fiber reinforced high-strength semi-lightweight concrete are presented in this paper. The properties investigated include the workability, behavior under compression, splitting tension, flexure, and shear. The compressive strength was about 9000 psi (62.1 MPa) for a unit weight of 130 lb/ft 3 (2083 kg/m 3). Silica fume and high-range water-reducing admixtures were used to obtain the high strength. The lightweight aggregate used was made of expanded shale. The primary independent variables were fiber content and fiber length. Hooked-end steel fibers were used at volume contents ranging from 75 to 150 lb/yd 3 (45 to 90 kg/m 3). Fiber lengths and the corresponding aspect (length/diameter) ratios were 1.2, 2.0, 2.4 in. (30, 50, 60 mm) and 60, 75, and 100, respectively. The results indicate that silica fume can be successfully used to obtain high strength. The brittleness of silica fume concrete can be overcome by using fibers. The addition of fibers provides a significant increase in Young's modulus, splitting tensile strength, and shear strength. Strength increase is also considerable under flexure. In all cases, fibers provide substantial improvement in ductility.