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Title: Prestressed concrete using KEVLAR reinforced tendons

Abstract

KEVLAR is a high strength, high modulus synthetic fiber manufactured by the E.I. DuPont de Nemours Company. The fiber is resistant to chloride and alkali attack. The resistance is enhanced when the fibers are assembled into a resin matrix and fabricated as rods. These properties suggest that KEVLAR reinforced rods may be a substitute for high strength steel prestress tendons in certain applications such as bridge decks and parking structures. This dissertation presents the background, theoretical development, and experimental investigations of KEVLAR reinforced rod strength, anchorage, fabrication and performance in prestressed concrete structures. The study concludes that KEVLAR has significant potential for these prestressed concrete applications. However, the reliability of the long term anchorage of the KEVLAR reinforced rods must be improved before production applications are undertaken. KEVLAR has a low shear strength compared to its tensile capacity. The anchorage of KEVLAR reinforced rods is sensitive to the shear forces generated in the anchorage assembly. Finite element analyses, using interface elements to simulate the addition of a mold release agent in a conic anchor, predict the behavior of resin socketed anchors. Test results confirm that mold release agents reduce the anchor shear stresses and suggest that moderate strength resins maymore » be used in the anchor. KEVLAR is nearly linearly elastic to failure, yet ductility of a structure is an important design concern. Prestressed concrete beam tests using both bonded and unbonded tendons demonstrated that ductile structural behavior is obtained. Methods of predicting the strength and deflection behavior of the prestressed beams are presented and the theoretical predictions are compared to the experimental results. The overall correlation between predicted and theoretical results is satisfactory.« less

Authors:
Publication Date:
Research Org.:
Cornell Univ., Ithaca, NY (USA)
OSTI Identifier:
6385649
Alternate Identifier(s):
OSTI ID: 6385649
Resource Type:
Miscellaneous
Resource Relation:
Other Information: Thesis (Ph.D)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; PRESTRESSED CONCRETE; MATERIALS TESTING; BUILDING MATERIALS; COMPOSITE MATERIALS; EXPERIMENTAL DATA; REINFORCED MATERIALS; CONCRETES; DATA; INFORMATION; MATERIALS; NUMERICAL DATA; TESTING 360601* -- Other Materials-- Preparation & Manufacture; 360603 -- Materials-- Properties

Citation Formats

Dolan, C.W. Prestressed concrete using KEVLAR reinforced tendons. United States: N. p., 1989. Web.
Dolan, C.W. Prestressed concrete using KEVLAR reinforced tendons. United States.
Dolan, C.W. Sun . "Prestressed concrete using KEVLAR reinforced tendons". United States. doi:.
@article{osti_6385649,
title = {Prestressed concrete using KEVLAR reinforced tendons},
author = {Dolan, C.W.},
abstractNote = {KEVLAR is a high strength, high modulus synthetic fiber manufactured by the E.I. DuPont de Nemours Company. The fiber is resistant to chloride and alkali attack. The resistance is enhanced when the fibers are assembled into a resin matrix and fabricated as rods. These properties suggest that KEVLAR reinforced rods may be a substitute for high strength steel prestress tendons in certain applications such as bridge decks and parking structures. This dissertation presents the background, theoretical development, and experimental investigations of KEVLAR reinforced rod strength, anchorage, fabrication and performance in prestressed concrete structures. The study concludes that KEVLAR has significant potential for these prestressed concrete applications. However, the reliability of the long term anchorage of the KEVLAR reinforced rods must be improved before production applications are undertaken. KEVLAR has a low shear strength compared to its tensile capacity. The anchorage of KEVLAR reinforced rods is sensitive to the shear forces generated in the anchorage assembly. Finite element analyses, using interface elements to simulate the addition of a mold release agent in a conic anchor, predict the behavior of resin socketed anchors. Test results confirm that mold release agents reduce the anchor shear stresses and suggest that moderate strength resins may be used in the anchor. KEVLAR is nearly linearly elastic to failure, yet ductility of a structure is an important design concern. Prestressed concrete beam tests using both bonded and unbonded tendons demonstrated that ductile structural behavior is obtained. Methods of predicting the strength and deflection behavior of the prestressed beams are presented and the theoretical predictions are compared to the experimental results. The overall correlation between predicted and theoretical results is satisfactory.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Sun Jan 01 00:00:00 EST 1989},
month = {Sun Jan 01 00:00:00 EST 1989}
}

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  • This study intends to relate the point-wise limit state design method to the ultimate behavior of reinforced-concrete shells as a unified approach. A vector algorithm developed on a Cray Y-MP supercomputer is suitable to implement an inelastic finite element program. A bending inelastic finite element model, which incorporates the rotating cracking model by layering the subdivided elements, is developed. Effects of large-deformation, tension-stiffening, and dowel action are ignored, and the bond between the concrete and steel and among the subdivided layers is assumed to be perfect. The biaxial behavior of uncracked concrete and the uniaxial behavior of a cracked elementmore » are assumed to be linear elastic in compression and in tension. Based on this analysis, the current design method provides adequate strength against an ultimate failure.« less
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