TY - GEN
T1 - Scaling of strength of FRP reinforced concrete beams without shear reinforcement
AU - Matta, F.
AU - Nanni, A.
AU - Hernandez, T. M.
AU - Benmokrane, B.
N1 - Funding Information:
The financial support of the NSF Industry/University Cooperative Research Center “Repair of Buildings and Bridges with Composites”, and the assistance of the Center’s industry members Hughes Brothers, Inc. and Pultrall, Inc. in supplying the GFRP reinforcement are gratefully acknowledged. The tests were performed at the Missouri University of Science and Technology Structures Lab, and special thanks are due to the lab’s electronic technicians for their assistance.
Publisher Copyright:
© 2008 Empa-Akademie. All rights reserved.
PY - 2008
Y1 - 2008
N2 - Among the unresolved issues in the design of structural concrete reinforced with fiber reinforced composite (FRP) bars, the understanding of size effect in the reduction of the shear strength of deep beams without shear reinforcement is of fundamental and practical significance. Size effect accrues primarily from the larger width of diagonal cracks as the effective depth is increased, and has been extensively documented in the case of steel reinforced concrete (RC) through a number of laboratory tests. In FRP RC, the lower longitudinal elastic modulus of the flexural reinforcement results in deeper and wider cracks. Yet, the calibration of any of the current semi-empirical design algorithms is based on test results of beams and one-way slabs with maximum effective depth of 360 mm, which is not representative of relevant large-scale applications. This paper presents and discusses the results of laboratory testing of large-size and scaled FRP RC beams without shear reinforcement, having maximum effective depth of 147, 294 and 883 mm, and effective reinforcement ratio of 0.12% and 0.24%. It is shown that the shear strength of the large-size specimens with less flexural reinforcement decreases on average by 55% compared with the smaller specimens. However, the conservativeness of the current design algorithms generally offsets the size effect. The provisions of the UK Institution of Structural Engineers (ISE) and the Italian National Research Council (CNR) provide the most accurate estimates, where the former yields more conservative and consistent results.
AB - Among the unresolved issues in the design of structural concrete reinforced with fiber reinforced composite (FRP) bars, the understanding of size effect in the reduction of the shear strength of deep beams without shear reinforcement is of fundamental and practical significance. Size effect accrues primarily from the larger width of diagonal cracks as the effective depth is increased, and has been extensively documented in the case of steel reinforced concrete (RC) through a number of laboratory tests. In FRP RC, the lower longitudinal elastic modulus of the flexural reinforcement results in deeper and wider cracks. Yet, the calibration of any of the current semi-empirical design algorithms is based on test results of beams and one-way slabs with maximum effective depth of 360 mm, which is not representative of relevant large-scale applications. This paper presents and discusses the results of laboratory testing of large-size and scaled FRP RC beams without shear reinforcement, having maximum effective depth of 147, 294 and 883 mm, and effective reinforcement ratio of 0.12% and 0.24%. It is shown that the shear strength of the large-size specimens with less flexural reinforcement decreases on average by 55% compared with the smaller specimens. However, the conservativeness of the current design algorithms generally offsets the size effect. The provisions of the UK Institution of Structural Engineers (ISE) and the Italian National Research Council (CNR) provide the most accurate estimates, where the former yields more conservative and consistent results.
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M3 - Conference contribution
AN - SCOPUS:85064081170
T3 - Proceedings of the 4th International Conference on FRP Composites in Civil Engineering, CICE 2008
BT - Proceedings of the 4th International Conference on FRP Composites in Civil Engineering, CICE 2008
A2 - Motavalli, Masoud
PB - Empa-Akademie
T2 - 4th International Conference on FRP Composites in Civil Engineering, CICE 2008
Y2 - 22 July 2008 through 24 July 2008
ER -