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Time-dependent crack growth and fracture in concrete

Thesis/Dissertation:

Abstract

The objectives of this thesis are to study time-dependent fracture behaviour in concrete. The thesis consists of an experimental study, costitutive modelling and numerical analysis. The experimental study was undertaken to investigate the influences of time on material properties for the fracture process zone and on crack growth and fracture in plain concrete structures. The experiments include tensile relaxation tests, bending tests on notched beams to determine fracture energy at varying deflection rates, and sustained bending and compact tensile tests. From the tensile relaxation tests, the envelope of the {sigma}-w relation does not seem to be influenced by holding periods, though some local detrimental effect does occur. Fracture energy seems to decrease as rates become slower. In the sustained loading tests, deformation (deflection or CMOD) growth curves display three stages, as usually observed in a creep rupture test. The secondary stage dominates the whole failure lifetime, and the secondary deformation rate appears to have good correlation with the failure lifetime. A crack model for time-dependent fracture is proposed, by applying the idea of the Fictitious Crack Model. In this model, a modified Maxwell model is introduced for the fracture process zone incorporated with the static {sigma}-w curve as a failure  More>>
Authors:
Publication Date:
Feb 01, 1992
Product Type:
Thesis/Dissertation
Report Number:
LUTVDG/TVBM-1011-1-132-1992
Reference Number:
SCA: 360603; PA: AIX-24:000668; SN: 93000912813
Resource Relation:
Other Information: TH: Diss. (TeknD).; PBD: Feb 1992
Subject:
36 MATERIALS SCIENCE; CONCRETES; CRACK PROPAGATION; CREEP; EXPERIMENTAL DATA; FRACTURE MECHANICS; FRACTURE PROPERTIES; FRACTURES; MATERIALS TESTING; STRESSES; TENSILE PROPERTIES; TIME DEPENDENCE; 360603; MECHANICAL PROPERTIES
OSTI ID:
10108667
Research Organizations:
Lund Univ. (Sweden). Dept of Building Technology
Country of Origin:
Sweden
Language:
English
Other Identifying Numbers:
Other: ON: DE93609044; TRN: SE9200241000668
Availability:
OSTI; NTIS; INIS
Submitting Site:
SWDN
Size:
[141] p.
Announcement Date:
Jun 30, 2005

Thesis/Dissertation:

Citation Formats

Ping, Zhou Fan. Time-dependent crack growth and fracture in concrete. Sweden: N. p., 1992. Web.
Ping, Zhou Fan. Time-dependent crack growth and fracture in concrete. Sweden.
Ping, Zhou Fan. 1992. "Time-dependent crack growth and fracture in concrete." Sweden.
@misc{etde_10108667,
title = {Time-dependent crack growth and fracture in concrete}
author = {Ping, Zhou Fan}
abstractNote = {The objectives of this thesis are to study time-dependent fracture behaviour in concrete. The thesis consists of an experimental study, costitutive modelling and numerical analysis. The experimental study was undertaken to investigate the influences of time on material properties for the fracture process zone and on crack growth and fracture in plain concrete structures. The experiments include tensile relaxation tests, bending tests on notched beams to determine fracture energy at varying deflection rates, and sustained bending and compact tensile tests. From the tensile relaxation tests, the envelope of the {sigma}-w relation does not seem to be influenced by holding periods, though some local detrimental effect does occur. Fracture energy seems to decrease as rates become slower. In the sustained loading tests, deformation (deflection or CMOD) growth curves display three stages, as usually observed in a creep rupture test. The secondary stage dominates the whole failure lifetime, and the secondary deformation rate appears to have good correlation with the failure lifetime. A crack model for time-dependent fracture is proposed, by applying the idea of the Fictitious Crack Model. In this model, a modified Maxwell model is introduced for the fracture process zone incorporated with the static {sigma}-w curve as a failure criterion, based on the observation of the tensile relaxation tests. The time-dependent {sigma}-w curve is expressed in an incremental law. The proposed model has been implemented in a finite element program and applied to simulating sustained flexural and compact tensile tests. Numerical analysis includes simulations of crack growth, load-CMOD curves, stress-failure lifetime curves, size effects on failure life etc. The numerical results indicate that the model seems to be able to properly predict the main features of time-dependent fracture behaviour in concrete, as compared with the experimental results. 97 refs.}
place = {Sweden}
year = {1992}
month = {Feb}
}