Details:

Creators:
Yu, Hailing ; Jeong, David Y.
Yu, Hailing ; Jeong, David Y. Less -
Corporate Creators:
John A. Volpe National Transportation Systems Center (U.S.)
Subject/TRT Terms:
[+]
Bonding Concrete Ties Elasticity (Mechanics) Failure Analysis Finite Element Method Prestressed Concrete Ties Railroad Ties Structural Analysis Wire
Resource Type:
In Proceedings
Geographical Coverage:
United States
Corporate Publisher:
American Society of Civil Engineers
NTL Classification:
AGR-INFRASTRUCTURE-INFRASTRUCTURE;AGR-INFRASTRUCTURE-Railroads;NTL-RAIL TRANSPORTATION-RAIL TRANSPORTATION;
Abstract:
Pretensioned concrete ties are increasingly employed in railroad high speed

and heavy haul applications. The bond between prestressing wires or strands and

concrete plays an important role in determining the transfer length of pretensioned

concrete members, but little research was done to characterize the transfer length in

terms of steel reinforcement and concrete factors for railroad concrete ties. Federal

Railroad Administration is sponsoring a comprehensive test program at Kansas State

University (KSU) aimed at quantitatively correlating prestressing steel and concrete

variables with the transfer length of pretensioned concrete crossties, and Volpe Center

has been applying the data obtained in the KSU test program to develop bond models

that can be used in transfer length prediction and failure analysis of concrete ties.

This paper describes finite element (FE) model development related to the

smooth prestressing wire whose dominant bonding mechanisms with concrete are

chemical adhesion and friction. The commercial FE software Abaqus is employed,

and the steel-concrete interface is discretized with cohesive elements. A user bond

model is developed within the elastoplastic framework and implemented for

axisymmetric and 3D cohesive elements. The bond model defines constitutive

relations in terms of normal and shear stresses vs. interfacial dilation and slips. The

bond behavior is initially linear elastic, followed by adhesion and friction that are

governed by a yield function and a plastic flow rule specific for the smooth wireconcrete

interface. The main bond material parameters are normal and shear elastic

stiffness, initial adhesive strength, plastic slip at which adhesion first breaks

completely, and coefficient of friction. Except for the coefficient of friction, which is

determined with reference to the open literature, the bond parameters are calibrated

from untensioned pullout tests and pretensioned prism tests conducted at KSU. The

calibrated bond parameters exhibit a dependence on the nominal compressive strength

of concrete at the time of pretension release. Because considerable concrete creeping

has been observed in the periods between pretension release and concrete strain

measurement in the test program, an additional concrete material parameter, basic

creep compliance, can be calculated and applied to adjust the concrete surface strain

data. The user bond model is then validated with transfer length data measured on

actual concrete crossties made with a smooth prestressing wire in a tie manufacturing

plant.


Format:
PDF
Funding:
RR19A2
Collection(s):
Volpe
Main Document Checksum:
[+]
urn:sha256:df3bff6c1de01544641c59788e85223352a3bbdde4d3552b07f2db3e769d5a37
Download URL:
https://rosap.ntl.bts.gov/view/dot/12177/dot_12177_DS1.pdf
File Type:

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