Punching shear strengthening of flat slabs with EBROG and EBRIG – FRP strips

Amiri, Somayeh; Talaeitaba, Sayed Behzad

doi:10.1016/j.istruc.2020.04.017

Cited by 11 publications

(4 citation statements)

References 36 publications

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“…The strengthening pattern comprised of 1- or 2-layer FRP strips bonded under slabs on two grooves which were 4 or 8 mm wide and depth ranged from 8–12 mm. Results demonstrated that such FRP patterns were able to enhance punching shear strength up to 60% for EBROG while it grew up to 28% for EBR [ 26 ].…”

Section: Introductionmentioning

confidence: 99%

Remediation of Punching Shear Failure Using Glass Fiber Reinforced Polymer (GFRP) Rods

et al. 2021

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The results of an experimental program on shear-strengthening of flat slabs using Glass Fiber Reinforced Polymer (GFRP) rods are presented. A total of seven specimens were tested under an upward concentric monotonic loading until failure. One specimen served as a control and was tested without any modification. The remaining six specimens were strengthened with post-installed GFRP rods in single (SG), double (DB), and radial (RD) patterns within shear critical parameters around the centric column. The results of this experimental study suggest that GFRP rods are capable of enhancing both the peak load and deformation capacity. Furthermore, brittle failure associated with punching shear failure was successfully avoided by all strengthening patterns. Of all of the patterns, the RD pattern resulted in maximum peak load increase and corresponding deformation capacity while the lowest bound was created by the SG pattern. The results suggested that SG, DB and RD patterns enhanced ultimate loads up to 9.1, 11.3 and 15.7% while corresponding deflections increased up to 109, 136 and 154%. Strain measurement on flexural reinforcement suggested that all strengthened specimens were able to withstand higher longitudinal strains than yield. It was further shown that reducing the spacing between the GFRP rods efficiently enhanced peak loads, nevertheless, neither this change was proportional, nor did it result in an enhanced energy dissipation capacity. In the end, recommendations of American Concrete Institute (ACI) for the shear strength of two-way systems were modified to incorporate the contributions from GFRP rods. The results indicate that the proposed analytical approach provides an excellent match with the experimental results.

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Section: Introductionmentioning

confidence: 99%

Remediation of Punching Shear Failure Using Glass Fiber Reinforced Polymer (GFRP) Rods

et al. 2021

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“…Brittleness and being followed by an unexpected reduction in load-bearing without any previous warning are the main concerns for this type of failure. Therefore, such an unacceptable failure should be prevented [2,3]. Various methods have been suggested for rehabilitating reinforced concrete (RC) flat slabs to enhance their punching shear capacity.…”

Section: Introductionmentioning

confidence: 99%

Experimental Investigation on the Rehabilitation of RC Flat Slabs Using CFRP Sheets to Enhance Punching Shear Capacity

Abdul Sahib,

Aghayari,

Moradi

et al. 2024

Buildings

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In this paper, the feasibility of strengthening a flat column–slab connection within the carbon fiber reinforced polymer (CFRP) has been investigated through experimental study. The experimental program includes a set of nine reinforced concrete flat slab specimens. Three unaltered specimens served as control slabs, while an additional six samples were strengthened with various CFRP configurations to enhance their shear capacity. The strain distribution, ductility, punching shear resistance, stiffness, and crack formation were studied. The result of experimental studies showed that in the direct method of strengthening in which two layers of unidirectional CFRP sheets were employed in two opposite directions, the ultimate punching shear resistance improved by 64%, 44.7%, and 15.3%, with respect to the location of the column connection, as compared with the control specimens. In the case of using one layer of unidirectional CFRP strips, the punching shear resistance was enhanced by approximately 16% and 39%, considering the configuration of CFRP sheets and the amount of strengthened and adhesive layers used. Following the outcomes of this research, the application of CFRPs in improving the resistance capacity of flat slabs against the punching shear is considerable. The reported outcomes were compared with the latest provisions of ACI to show the efficiency of the presented strengthening. Finally, a parametric study was performed assuming different loading locations to assess the effect of the loading region on the response of RC slabs. Results indicate that approaching the loading location toward the RC slab supports results of an increase in the load-bearing capacity and a reduction in the ductility of the RC slab.

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“…They are positioned directly over columns without beams, which facilitates a direct transfer of load from the slab to the columns. The absence of beams offers several advantages, including reduced building height, easy integration of vertical shafts, layout flexibility, simplified reinforcement placement, faster construction, and form simplification [2][3][4]. The design of a flat slab is mainly controlled by punching shear that exists at the vicinity of the slab-column connection due to high shear stresses.…”

Section: Introductionmentioning

confidence: 99%

Comparative Analysis of Shear Strength Prediction Models for Reinforced Concrete Slab–Column Connections

Wahab,

Mahmoudabadi,

Waqas

et al. 2024

Advances in Civil Engineering

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This research focuses on a comprehensive comparative analysis of shear strength prediction in slab–column connections, integrating machine learning, design codes, and finite element analysis (FEA). The existing empirical models lack the influencing parameters that decrease their prediction accuracy. In this paper, current design codes of American Concrete Institute 318-19 (ACI 318-19) and Eurocode 2 (EC2), as well as innovative approaches like the compressive force path method and machine learning models are employed to predict the punching shear strength using a comprehensive database of 610 samples. The database consists of seven key parameters including slab depth (ds), column dimension (cs), shear span ratio (av/d), yield strength of longitudinal steel (fy), longitudinal reinforcement ratio (ρl), ultimate load-carrying capacity (Vu), and concrete compressive strength (fc). Compared with the design codes and other machine learning models, the particle swarm optimization-based feedforward neural network (PSOFNN) performed the best predictions. PSOFNN predicted the punching shear of flat slab with maximum accuracy with R2 value of 99.37% and least MSE and MAE values of 0.0275% and 1.214%, respectively. The findings of the study are validated through FEA of slabs to confirm experimental results and machine learning predictions that showed excellent agreement with PSOFNN predictions. The research also provides insight into the application of metaheuristic models along with ANN, revealing that not all metaheuristic models can outperform ANN as usually perceived. The study also highlights superior predictive capabilities of EC2 over ACI 318-19 for punching shear values.

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Punching shear strengthening of flat slabs with EBROG and EBRIG – FRP strips

Cited by 11 publications

References 36 publications

Remediation of Punching Shear Failure Using Glass Fiber Reinforced Polymer (GFRP) Rods

Remediation of Punching Shear Failure Using Glass Fiber Reinforced Polymer (GFRP) Rods

Experimental Investigation on the Rehabilitation of RC Flat Slabs Using CFRP Sheets to Enhance Punching Shear Capacity

Comparative Analysis of Shear Strength Prediction Models for Reinforced Concrete Slab–Column Connections

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