Modified Equivalent Compression Stress Block for Normal-Strength Concrete Flexural Design using Energy Modeling

Authors

  • Hamdy El-Gohary Civil Engineering Department, College of Engineering and Islamic Architecture, Umm Al-Qura University, Makkah, Saudi Arabia | Structural Engineering Department, Faculty of Engineering, Mansoura University, Mansoura, Egypt
Volume: 14 | Issue: 3 | Pages: 13851-13855 | June 2024 | https://doi.org/10.48084/etasr.7094

Abstract

The equivalent stress block is recommended for use in the design of reinforced concrete sections to simplify the analysis of the composite behavior of concrete and steel reinforcement. In most current codes, a rectangular equivalent stress block is provided. The design parameters of the equivalent block were recommended many years ago. Due to the importance of the equivalent stress block concept, numerous investigations have been performed to increase its accuracy. In the current paper, an exploration of the rectangular equivalent stress block has been carried out using the energy modeling approach. Energy modeling is a new general approach for studying the behavior of concrete elements. In this method, the energy consumed (work done) can be determined by integrating the force-displacement diagram (in the current study this will be the concrete stress-strain curve in compression). Schematic and equivalent stress-strain curves for concrete in uniaxial compression provided in most current codes and relevant textbooks were considered in this research. The codes taken into account in the current study are ACI-318-19, Canadian Code CSA A23.3-04, Eurocode EC-2, and Chinese standard GB 500 10 – 2002. The energy consumed by these curves for different values of concrete strength has been compared with numerous experimental results. This comparison shows that the results of the equivalent stress block provided in most of the considered current codes are conservative. Applying the energy modeling for the considered experimental stress-strain curves a modified equivalent stress block is recommended for practical use. The results of the proposed equivalent stress block are in good agreement with the experimental ones. The ratio between the predicted total energy engaging the proposed model and the total energy calculated for the experimental results ranges between 0.95 and 1.08 with a mean value equal to unity.

Keywords:

concrete, stress-strain curve, energy modeling, equivalent stress block

Downloads

Download data is not yet available.

References

E. Hognestad, N. W. Hanson, and D. McHenry, "Concrete Stress Distribution in Ultimate Strength Design," Journal Proceedings, vol. 52, no. 12, pp. 455–480, Dec. 1955.

E. Hognestad, "Study of combined bending and axial load in reinforced concrete members," University of Illinois. Engineering Experiment Station. Bulletin, no. 399, 1951, [Online]. Available: https://hdl.handle.net/2142/4360.

S. Narayanan, "A Case for the Use of Rectangular Stress Block in the Revision of IS: 456 (2000)," Indian Concrete Journal, vol. 95, no. 9, pp. 7–15, Nov. 2021.

J. Peng, J. C. M. Ho, H. J. Pam, and Y. L. Wong, "Equivalent stress block for normal-strength concrete incorporating strain gradient effect," Magazine of Concrete Research, vol. 64, no. 1, pp. 1–19, Jan. 2012.

J. Peng, J. C. M. Ho, and H. J. Pam, "Modification on Equivalent Stress Block of Normal-Strength Concrete by Incorporating Strain Gradient Effects," Procedia Engineering, vol. 14, pp. 2246–2253, Jan. 2011.

S. J. Alghamdi, "Prediction of Concrete’s Compressive Strength via Artificial Neural Network Trained on Synthetic Data," Engineering, Technology & Applied Science Research, vol. 13, no. 6, pp. 12404–12408, Dec. 2023.

K. P. Rusna and V. G. Kalpana, "Using Artificial Neural Networks for the Prediction of the Compressive Strength of Geopolymer Fly Ash," Engineering, Technology & Applied Science Research, vol. 12, no. 5, pp. 9120–9125, Oct. 2022.

O. Radaikin, "Comparative Analysis of Various Diagrams of Concrete Deformation According to the Criterion of Energy Consumption for Deformation and Destruction," Bulletin of Belgorod State Technological University named after. V. G. Shukhov, vol. 4, no. 10, pp. 29–39, Nov. 2019.

H. A. El-Gohary, "A Simplified Energy Model Approach for the Determination of Long-Term Crack Width in Reinforced Concrete Elements," Engineering, Technology & Applied Science Research, vol. 13, no. 3, pp. 10744–10747, Jun. 2023.

ACI Committee 318, ACI CODE-318-19(22): Building Code Requirements for Structural Concrete and Commentary (Reapproved 2022). Farmington Hills, MI, USA: ACI, 2019.

J. Wight, Reinforced Concrete: Mechanics and Design, 7th ed. Hoboken, NJ, USA: Pearson, 2015.

CSA A23.3-14. Design of Concrete Structures. Canadian Standards Association, Ontario, Canada, 2014

O. Chaallal and M. Lachemi, Reinforced Concrete Structures : Design according to CSA A23.3-04. Québec, Canada: Presses Université du Québec, 2010.

S. Brzev and J. Pao, Reinforced Concrete Design: A Practical Approach, 2nd ed. Pearson Learning Solutions, 2012.

EN 1992-1-1:2004: Eurocode 2: Design of concrete structures - Part 1-1: General rules and rules for buildings. 2004.

R. Narayanan and A. Beeby, Designers’ Guide to EN 1992-1-1 and EN 1992-1-2 Eurocode 2: Design of Concrete Structures. General rules and rules for buildings and structural fire design. Thomas Tellford, 1996.

"GB 50010-2010(2015) English Version, GB 50010-2010(2015) Code for design of concrete structures (English Version)," Code of China. https://www.codeofchina.com/standard/GB50010-2010(2015).html.

A. Mohamad Ali, B. Farid, and A. Al-Janabi, "Stress - Strain Relationship For Concrete in Compression Made of Local Materials," Journal of King Abdulaziz University-Engineering Sciences, vol. 2, no. 1, pp. 183–194, 1990.

V. Domínguez-Cartes, D. Ramos-Cabeza, M. L. de la Torre, and F. Salguero-Andújar, "Complete Generalization of the Equations for the Stress–Strain Curves of Concrete under Uniaxial Compression," Materials, vol. 16, no. 9, Jan. 2023, Art. no. 3387.

A. M. Lafta, S. K. Ahmed, and M. S. Matrood, "Polynomial equation of stress-strain curve for normal concrete," AIP Conference Proceedings, vol. 2386, no. 1, Jan. 2022, Art. no. 080001.

L. Yafei, Z. Tao, Y. Jie, J. Tao, Z. Qingfang, and H. Hexuan, "A Simplified Uniaxial Stress-strain Curve of Concrete and Its Application in Numerical Simulation," E3S Web of Conferences, vol. 283, 2021, Art. no. 01045.

Downloads

How to Cite

[1]
H. El-Gohary, “Modified Equivalent Compression Stress Block for Normal-Strength Concrete Flexural Design using Energy Modeling”, Eng. Technol. Appl. Sci. Res., vol. 14, no. 3, pp. 13851–13855, Jun. 2024.

Metrics

Abstract Views: 155
PDF Downloads: 75

Metrics Information