Determination of the Optimal Pattern for RC Slab Strengthening Against Punching Shear Using FRP Fan

Document Type : Original Article

Authors

1 Ph.D. Candidate in Structural Engineering, Faculty of Civil Engineering, Urmia University international Pardis, Urmia, Iran

2 Assistant Professor, Structural Engineering department, Ministry of Road, Housing &Urban development, Tehran, Iran

3 Assistant Professor, Faculty of Civil Engineering, Urmia University, Urmia, Iran

Abstract

Reinforced concrete (RC) flat slabs are utilized, because of their advantages such as covering large spans without beams, ease of execution increased construction speed, and decreased overall building height. However, this system is at risk of punching shear failure. In recent years, various methods have been proposed to strengthen RC flat slabs, but the latest of ones are penetrating and passing fiber reinforced polymers (FRPs) fan through the slab thickness. This method has been successfully evaluated in previous studies, and this research is tried to assess the most suitable pattern of FRP fan installation for punching shear. To reach this goal, two specimens of flab slabs from the available experimental studies, including one control and one strengthened specimen under pushover loading are similarly modeled and analyzed in ABAQUS Software to prove the accuracy of the analytical results. Then after considering two types of strengthening scheme with different patterns and changing the number of holes passing through the thickness of the slab, 18 samples are modeled in this Software. These nonlinear analyses are performed to determine the best pattern in terms of bearing capacity, ultimate displacement, ductility, energy absorption, stiffness and to find the best distance of FRP fibers form the column face. The results showed that the L1 which FRPs were placed in two parallel rows around the four sides of the column, noticed best among the other models. Among the radial patterns, the R5 which has six rows of FRPs arranged radially around the center of the slab has shown the best performance. Whatever the method of FRP fan strengthening is the load-bearing capacity, absorbed energy, and stiffness increased 137%, 535% and 21.6% compared to control slab, respectively. The results of the analysis can be used to determine the appropriate pattern of slab strengthening considering the economic aspect.

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References

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History

  • Receive Date: 16 September 2019
  • Revise Date: 17 December 2019
  • Accept Date: 19 January 2020

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