00763245

Monograph

http://onlinepubs.trb.org.../NCHRP045_Final_Report.pdf

This Innovations Deserving Exploratory Analysis (IDEA) report presents the experimental investigation carried out to evaluate the performance characteristics of basalt fiber reinforced concrete and basalt bar reinforced concrete. All the experiments were conducted following the American Society for Testing and Materials (ASTM) standards. The test program was conducted for fresh and hardened concrete properties. The fresh concrete properties consisted of the following tests: slump, Vebe slump, Vebe time, concrete temperature, air content and unit weight. The hardened concrete properties determined were compressive strength, static modulus, flexural strength, load-deflection behavior, comparison of load-deflection curves, ASTM toughness indices, first crack toughness, post crack behavior, Japanese standard method for toughness indices and equivalent flexural strength. The test results show that the basalt fiber can be easily mixed in the concrete without any balling, bridging or segregation. There was a noticeable increase in the post crack energy absorption capacity and ductility due to the addition of basalt fibers. The impact resistance increased as the fiber content increased. For beams reinforced with basalt bars supplied by the manufacturer, the load deflection curves were plotted and the toughness indices and first crack toughness were calculated in a similar way as the ASTM standards for the beams reinforced with basalt fibers. Toughness indices according to the Japanese standard method and the equivalent flexural strength were also calculated for the beams reinforced with basalt bars supplied by the manufacturer. For beams reinforced with basalt bars designed and cast in the lab, strain across the depth of the beams was measured using electrical resistance strain gages, and deflection was measured using a magnetic dial gauge. These tests indicated that there was insufficient bond strength and the bars slipped gradually before the ultimate load was released. Beams with increased development lengths failed suddenly with breaking of rods. The ultimate-load and cracking-load moments and the deflections of the basalt rod reinforced concrete beams were compared. The tension tests were conducted on the basalt bars and on a cable, having two basalt bars twisted together. Graphs of stress vs. strain were plotted and the modulus of elasticity of the basalt bars was calculated.

This NCHRP-IDEA investigation was conducted by the South Dakota School of Mines and Technology, Rapid City, South Dakota. The fibers and bars were supplied by Research & Technology, Inc., Madison, Wisconsin. The original project title was Performance Evaluation of Basalt Fibers and Composite Rebars as Concrete Reinforcement. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved

NCHRP-IDEA Project 45

NCHRP-45

English

96 p.

1998-11

NCHRP-IDEA Program Project Final Report

Appendices (3) ; Figures; Photos; References (21) ; Tables

Air content; Basalt; Bond strength (Materials); Compressive strength; Concrete tests; Deflection; Deformation curve; Ductility; Energy absorption; Fiber reinforced concrete; Flexural strength; Fresh concrete; Loads; Modulus of elasticity; Reinforced concrete; Reinforcing bars; Slump test; Technological innovations; Temperature; Tension tests; Toughness; Weight

National Cooperative Highway Research Program

Hardened concrete

Highways; Materials; I32: Concrete

NTL, TRIS, TRB

May 20 2001 12:00AM