TY - GEN
T1 - Measuring three-dimensional damage of mortar in compression with X-Ray microtomography and digital image correlation
AU - Lawler, John S.
AU - Keane, Denis T
AU - Shah, Surendra P.
N1 - Funding Information:
The authors gratefully acknowledge support of the National Science Foundation Center for Advanced Cement-Based Materials (ACBM) at Northwestern University. This work was also sponsored (in part) by the Air Force Office of Scientific Research, USAF, under grant/contract number F49620-96-0377. The views and conclusions contained herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of the Air Force Office of Scientific Research or the U.S. Government. Portions of this work were performed at the DuPont-Northwestern-Dow Collaborative Access Team (DND-CAT) Synchrotron Research Center located at Sector 5 of the Advanced Photon Source. DND-CAT is supported by the E.I. DuPont de Nemours & Co., The Dow Chemical Company, the U.S. National Science Foundation through Grant DMR-9304725 and the State of Illinois through the Department of Commerce and the Board of Higher Education Grant IB HE HECA NWU 96. Use of the Advanced Photon Source was supported by the U.S. Department of Energy, Basic Energy Sciences, Office of Energy Research under Contract No. W-31-102-Eng-38.
Funding Information:
The authors gratefully acknowledge support of the National Science Foundation Center for Advanced Cement-Based Materials (ACBM) at Northwestern University. This work was also sponsored (in part) by the Air Force Office of Scientific Research, USAF, under grant/contract number F49620-96-0377. The views and conclusions contained herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of the Air Force Office of Scientific Research or the U.S. Government. Portions of this work were performed at the DuPont-Northwestern-Dow Collaborative Access Team (DND-CAT) Synchrotron Research Center located at Sector 5 of the Advanced Photon Source. DND-CAT is supported by the E.I. DuPont de Nemours & Co., The Dow Chemical Company, the U.S. National Science Foundation through Grant DMR-9304725 and the State of Illinois through the Department of Commerce and the Board of Higher Education Grant IBHE HECA NWU 96. Use of the Advanced Photon Source was supported by the U.S. Department of Energy, Basic Energy Sciences, Office of Energy Research under Contract No. W-31-102-Eng-38.
Publisher Copyright:
© 2000 American Concrete Institute. All rights reserved.
PY - 2000/1/1
Y1 - 2000/1/1
N2 - The fracture process of cement-based materials caused by compressive loading is a complex, three-dimensional phenomenon that occurs as a result of material heterogeneity and complicated mixed-mode cracking mechanisms. However, obtaining three-dimensional information describing this process requires equipment- and time-intensive techniques. One such technique is X-ray Microtomography, which provides high resolution data, but is limited to small specimens. A more straightforward technique, Digital Image Correlation (DIC), can be used to characterize the fracture pattern of a wider range of specimens, but only in two dimensions on the surface. In order to determine the relationship between surface and internal cracking, mortar specimens were tested in compression and examined using both DIC and X-ray Microtomography. Microtomography is an X-ray technique that can be used to produce three-dimensional images which reveal the full internal structure of the specimen, including cracks and pores. DIC is a Computer Vision technique that compares successive images to measure two-dimensional deformation on the surface of the specimen, providing information on the location and opening of surface cracks. Rectangular mortar specimens (25.4 mm x 12.7 mm x 12.7 mm) were loaded to certain levels past the peak stress to induce significant cracking and then unloaded. Deformations of the unloaded specimen were measured with DIC and used to determine crack shape, size and location. This surface phenomena was compared to the shape and size of internal cracks seen in tomographic reconstructions of the same specimen. It was observed that these techniques give complementary information about crack geometry and development.
AB - The fracture process of cement-based materials caused by compressive loading is a complex, three-dimensional phenomenon that occurs as a result of material heterogeneity and complicated mixed-mode cracking mechanisms. However, obtaining three-dimensional information describing this process requires equipment- and time-intensive techniques. One such technique is X-ray Microtomography, which provides high resolution data, but is limited to small specimens. A more straightforward technique, Digital Image Correlation (DIC), can be used to characterize the fracture pattern of a wider range of specimens, but only in two dimensions on the surface. In order to determine the relationship between surface and internal cracking, mortar specimens were tested in compression and examined using both DIC and X-ray Microtomography. Microtomography is an X-ray technique that can be used to produce three-dimensional images which reveal the full internal structure of the specimen, including cracks and pores. DIC is a Computer Vision technique that compares successive images to measure two-dimensional deformation on the surface of the specimen, providing information on the location and opening of surface cracks. Rectangular mortar specimens (25.4 mm x 12.7 mm x 12.7 mm) were loaded to certain levels past the peak stress to induce significant cracking and then unloaded. Deformations of the unloaded specimen were measured with DIC and used to determine crack shape, size and location. This surface phenomena was compared to the shape and size of internal cracks seen in tomographic reconstructions of the same specimen. It was observed that these techniques give complementary information about crack geometry and development.
KW - Concretes
KW - Digital image
KW - Evaluation
KW - Fracture
KW - Tomography
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M3 - Conference contribution
AN - SCOPUS:85030668910
T3 - American Concrete Institute, ACI Special Publication
SP - 187
EP - 202
BT - High-Performance Concrete
A2 - Russell, H.G.
PB - American Concrete Institute
T2 - High-Performance Concrete Research to Practice 1999
Y2 - 14 March 1999 through 19 March 1999
ER -