Comprehensive concrete fracture tests: Size effects of Types 1 & 2, crack length effect and postpeak

Christian G. Hoover; Zdeněk Z. Bažant

doi:10.1016/j.engfracmech.2013.08.008

Comprehensive concrete fracture tests: Size effects of Types 1 & 2, crack length effect and postpeak

Christian G. Hoover, Zdeněk Z. Bažant

Research output: Contribution to journal › Article › peer-review

119 Scopus citations

Abstract

The comprehensive fracture tests of notched and unnotched beams presented in the preceding paper are evaluated to clarify the size effects and fracture energy dissipation. The test results for beams with notches of various lengths agree closely with Bažant's Type 2 size effect law and yield the value of the initial fracture energy G_f. Since nearly complete post-peak softening load-displacement curves have been obtained, the total energy dissipation by fracture can be accurately evaluated and used to determine the RILEM total fracture energy G_F. For the present concrete, G_F/G_f≈2. The transition between the Type 1 and 2 size effects are determined and is found to be very different from that assumed in Hu and Duan's boundary effect model. Determination of a universal size effect law fitting the beam strengths for all the sizes and all notch depths is relegated to a subsequent paper.

Original language	English (US)
Pages (from-to)	281-289
Number of pages	9
Journal	Engineering Fracture Mechanics
Volume	110
DOIs	https://doi.org/10.1016/j.engfracmech.2013.08.008
State	Published - Sep 2013
Externally published	Yes

Keywords

Cohesive crack model
Flexural strength
Fracture testing
Scaling of strength
Size effect law

ASJC Scopus subject areas

General Materials Science
Mechanics of Materials
Mechanical Engineering

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10.1016/j.engfracmech.2013.08.008

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@article{dae7cb34fd56429f82cf8d3165098a69,

title = "Comprehensive concrete fracture tests: Size effects of Types 1 & 2, crack length effect and postpeak",

abstract = "The comprehensive fracture tests of notched and unnotched beams presented in the preceding paper are evaluated to clarify the size effects and fracture energy dissipation. The test results for beams with notches of various lengths agree closely with Ba{\v z}ant's Type 2 size effect law and yield the value of the initial fracture energy Gf. Since nearly complete post-peak softening load-displacement curves have been obtained, the total energy dissipation by fracture can be accurately evaluated and used to determine the RILEM total fracture energy GF. For the present concrete, GF/Gf≈2. The transition between the Type 1 and 2 size effects are determined and is found to be very different from that assumed in Hu and Duan's boundary effect model. Determination of a universal size effect law fitting the beam strengths for all the sizes and all notch depths is relegated to a subsequent paper.",

keywords = "Cohesive crack model, Flexural strength, Fracture testing, Scaling of strength, Size effect law",

author = "Hoover, {Christian G.} and Ba{\v z}ant, {Zden{\v e}k Z.}",

note = "Funding Information: Financial support from the U.S. Department of Transportation, provided through Grant 20778 from the Infrastructure Technology Institute of Northwestern University, is gratefully appreciated. Additional support for analysis was provided by NSF grant CMMI-1129449 to Northwestern University. ",

year = "2013",

month = sep,

doi = "10.1016/j.engfracmech.2013.08.008",

language = "English (US)",

volume = "110",

pages = "281--289",

journal = "Engineering Fracture Mechanics",

issn = "0013-7944",

publisher = "Elsevier BV",

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T1 - Comprehensive concrete fracture tests

T2 - Size effects of Types 1 & 2, crack length effect and postpeak

AU - Hoover, Christian G.

AU - Bažant, Zdeněk Z.

N1 - Funding Information: Financial support from the U.S. Department of Transportation, provided through Grant 20778 from the Infrastructure Technology Institute of Northwestern University, is gratefully appreciated. Additional support for analysis was provided by NSF grant CMMI-1129449 to Northwestern University.

PY - 2013/9

Y1 - 2013/9

N2 - The comprehensive fracture tests of notched and unnotched beams presented in the preceding paper are evaluated to clarify the size effects and fracture energy dissipation. The test results for beams with notches of various lengths agree closely with Bažant's Type 2 size effect law and yield the value of the initial fracture energy Gf. Since nearly complete post-peak softening load-displacement curves have been obtained, the total energy dissipation by fracture can be accurately evaluated and used to determine the RILEM total fracture energy GF. For the present concrete, GF/Gf≈2. The transition between the Type 1 and 2 size effects are determined and is found to be very different from that assumed in Hu and Duan's boundary effect model. Determination of a universal size effect law fitting the beam strengths for all the sizes and all notch depths is relegated to a subsequent paper.

AB - The comprehensive fracture tests of notched and unnotched beams presented in the preceding paper are evaluated to clarify the size effects and fracture energy dissipation. The test results for beams with notches of various lengths agree closely with Bažant's Type 2 size effect law and yield the value of the initial fracture energy Gf. Since nearly complete post-peak softening load-displacement curves have been obtained, the total energy dissipation by fracture can be accurately evaluated and used to determine the RILEM total fracture energy GF. For the present concrete, GF/Gf≈2. The transition between the Type 1 and 2 size effects are determined and is found to be very different from that assumed in Hu and Duan's boundary effect model. Determination of a universal size effect law fitting the beam strengths for all the sizes and all notch depths is relegated to a subsequent paper.

KW - Cohesive crack model

KW - Flexural strength

KW - Fracture testing

KW - Scaling of strength

KW - Size effect law

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U2 - 10.1016/j.engfracmech.2013.08.008

DO - 10.1016/j.engfracmech.2013.08.008

M3 - Article

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SN - 0013-7944

VL - 110

SP - 281

EP - 289

JO - Engineering Fracture Mechanics

JF - Engineering Fracture Mechanics

ER -

Comprehensive concrete fracture tests: Size effects of Types 1 & 2, crack length effect and postpeak

Abstract

Keywords

ASJC Scopus subject areas

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