27 Evaluation of Fatigue Damage in RC Slabs Considering Water Infiltration …
333
can be reasonably estimated by the velocity smaller than 2300 m/s, which is obtained
from the tomography with sufficient density of wave/ray paths. For the in-situ bridge
deck evaluation, when sufficient AE sources are obtained, spreading over the area of
measurement, resulting in a reliable ray paths density, identification of aggregation
can be implemented with the AE and elastic wave tomography.
27.5 Conclusions
In this study, to know the fatigue failure progress of RC deck in consideration of
water infiltration, a wheel loading test of a RC slab filled with water on the surface
is carried out with elastic wave tomography combined AE activity. The obtained
results are shown below.
1. According to tomograms by steps of wheel loading test with water, low velocity
zones continued to transversal direction until fatigue limit. As a result, in the
case of water infiltration, fatigue damage progresses from the cracks developed
initially.
2. In tomographic approaches, elastic wave/ray path density is crucially important
to provide accurate and reliable results. By the tomograms obtained by the combination of elastic wave tomography and AE tomography, Aggregation which is
one of the most nuisance forms of the damage peculiarly in concrete slabs, is
successfully evaluated as velocity areas smaller than 2300 m/s.
Acknowledgements This study is implemented under the support of The Cross-Ministerial
Strategic Innovation Promotion Program (SIP). The experiment was conducted in College of Engineering, Nihon University. We would like to express our sincere appreciation to Prof. Iwaki of
Nihon University for his experimental support as well as vital discussions.
References
1. The Ministry of Land, Infrastructure, Transport and Tourism: Annual report 2015 on Maintenance of Roads, Japan, 2015, https://www.mlit.go.jp/hakusyo/mlit/h26/hakusho/h27/index.html
(in Japanese)
2. T. Shiotani, H. Ohtsu, S. Momoki, H.K. Chai, H. Onishi, T. Kamada, Damage evaluation for
concrete bridge deck by means of stress wave techniques. J. Bridge Eng. 17, 847–856 (2012)
3. Y. Kobayashi, T. Shiotani,Seismic tomography with estimation of source location for concrete
structure, inStructural Faults and Repair 2012 (CD-ROM, Edinburgh, Scotland, 2012)
4. T. Shiotani, H. Asaue, T. Nishida, T. Maeshima, Y. Tanaka, Evolution of fatigue damage in
wheel-loading tests evaluated by 3D elastic-wave tomography. J. Disaster Res. 487–495 (2017)
5. Y. Kobayashi, T. Shiotani, H. Shiojiri, Damage identification using seismic travel time tomography on the basis of evolutional wave velocity distribution model, in Proceedings of Structural
Faults and Repair 2006 (CD-ROM, 2006)
333
can be reasonably estimated by the velocity smaller than 2300 m/s, which is obtained
from the tomography with sufficient density of wave/ray paths. For the in-situ bridge
deck evaluation, when sufficient AE sources are obtained, spreading over the area of
measurement, resulting in a reliable ray paths density, identification of aggregation
can be implemented with the AE and elastic wave tomography.
27.5 Conclusions
In this study, to know the fatigue failure progress of RC deck in consideration of
water infiltration, a wheel loading test of a RC slab filled with water on the surface
is carried out with elastic wave tomography combined AE activity. The obtained
results are shown below.
1. According to tomograms by steps of wheel loading test with water, low velocity
zones continued to transversal direction until fatigue limit. As a result, in the
case of water infiltration, fatigue damage progresses from the cracks developed
initially.
2. In tomographic approaches, elastic wave/ray path density is crucially important
to provide accurate and reliable results. By the tomograms obtained by the combination of elastic wave tomography and AE tomography, Aggregation which is
one of the most nuisance forms of the damage peculiarly in concrete slabs, is
successfully evaluated as velocity areas smaller than 2300 m/s.
Acknowledgements This study is implemented under the support of The Cross-Ministerial
Strategic Innovation Promotion Program (SIP). The experiment was conducted in College of Engineering, Nihon University. We would like to express our sincere appreciation to Prof. Iwaki of
Nihon University for his experimental support as well as vital discussions.
References
1. The Ministry of Land, Infrastructure, Transport and Tourism: Annual report 2015 on Maintenance of Roads, Japan, 2015, https://www.mlit.go.jp/hakusyo/mlit/h26/hakusho/h27/index.html
(in Japanese)
2. T. Shiotani, H. Ohtsu, S. Momoki, H.K. Chai, H. Onishi, T. Kamada, Damage evaluation for
concrete bridge deck by means of stress wave techniques. J. Bridge Eng. 17, 847–856 (2012)
3. Y. Kobayashi, T. Shiotani,Seismic tomography with estimation of source location for concrete
structure, inStructural Faults and Repair 2012 (CD-ROM, Edinburgh, Scotland, 2012)
4. T. Shiotani, H. Asaue, T. Nishida, T. Maeshima, Y. Tanaka, Evolution of fatigue damage in
wheel-loading tests evaluated by 3D elastic-wave tomography. J. Disaster Res. 487–495 (2017)
5. Y. Kobayashi, T. Shiotani, H. Shiojiri, Damage identification using seismic travel time tomography on the basis of evolutional wave velocity distribution model, in Proceedings of Structural
Faults and Repair 2006 (CD-ROM, 2006)