Strengthening concrete slabs for punching shear with CFRP laminates

by Kyriakos Sissakis

Publisher: National Library of Canada in Ottawa

Written in English
Published: Downloads: 218
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Edition Notes

Thesis (M.A.Sc.) -- University of Toronto, 2002.

SeriesCanadian theses = -- Thèses canadiennes
The Physical Object
FormatMicroform
Pagination3 microfiches : negative.
ID Numbers
Open LibraryOL20407068M
ISBN 100612786048
OCLC/WorldCa56329447

Binici, B. (). “Punching shear strengthening of reinforced concrete slabs using fiber reinforced polymers.” Dissertation submitted to The Univ. of Texas at Austin in partial fulfillment of the requirements of Doctor of Philosophy, punching shear strength of approximately 43%. Punching shear strength as function of slab rotation The opening of the critical shear crack reduces the strength of the inclined concrete compression strut carrying shear and eventually leads to the punching shear failure. According to Muttoni and Schwartz,12 the width of the critical crack can.   Title: Influence of the positioning of CFRP laminates for improving punching shear capacity of column-to-slab connections Author(s): Hikmatullah Akhundzada, Ted Donchev, Diana Petkova and Abdul Mahbob Samsoor Publication: Symposium Paper Volume: Issue: Appears on pages(s): Keywords: Punching shear failure, RC flat slabs, column to slab connection, CFRP laminates Author: Hikmatullah Akhundzada, Ted Donchev, Diana Petkova, Abdul Mahbob Samsoor.   This paper presents results of punching tests carried out in four reinforced concrete flat slabs, one of them without shear reinforcement and others strengthened with CFRP dowels. Slabs were mm square meters and 60 mm thick and were subjected to mid span loadings until by: 1.

  Sika carbon fibre strengthening plates are ideal for strengthening concrete, timber and masonry structures for load increase. Sika CarboDur plates are bonded onto the structure as external. This study presents the results of experiments conducted on a new economical and easy to install strengthening technique for flat plates against punching failures. Four test specimens that were simply supported along four edges with corners free to lift up, representing the interior slab-column connection were tested. The concrete strength and tension longitudinal reinforcement ratio of the.   Abstract. Carbon Fiber Reinforced Polymer (CFRP) retrofitted application has become widespread in the last decade due to its unique advantages. This paper presents the punching shear strength enhancement of flat slabs which can be achieved with CFRP by embedding it through the slab section and attaching it externally on the tension by: 1. The dominant failure mode for flat slabs strengthened with FRP grids is found to be deboning of FRP grids due to the small slab depth. In addition to the increased shear capacity of the slab up to a reasonable value, this method of strengthening is capable of changing slab failure from the shear mode to the flexure mode.

One possibility for strengthening existing flat slabs consists on gluing fibre reinforced polymers (FRPs) at the concrete surface. When applied on top of slab–column connections, this technique allows increasing the flexural stiffness and strength of the slab as well as its punching strength. Nevertheless, the higher punching strength is associated to a reduction on the deformation capacity.   An experimental study of full-scale reinforced concrete flat slabs crosswise strengthened with prestressed carbon fiber-reinforced polymer (CFRP) straps against punching shear was performed. The effects of two strap anchoring systems and of slab thickness on punching behavior were by:   Sissakis, K., and S. A. Sheikh. "Strengthening Concrete Slabs for Punching Shear with Carbon Fiber-Reinforced Polymer Laminates." ACI Structutural Journal (1): Smith, Scott T., Hu Shenghua, Seo Jin Kim, and Rudolf Seracino. "FRP-Strengthened RC Slabs Anchored with FRP Anchors." Engineering Structures 33 (4): Punching in slabs is generally seen by the application of concentrated loads or to the presence of columns. One of the major phenomenon related to flat slabs is its punching shear capacity at slab column connection. Provided that bending capacity is installed, punching shear failure is due to the development of a truncated cone-shaped surface at the slab-column connection.

Strengthening concrete slabs for punching shear with CFRP laminates by Kyriakos Sissakis Download PDF EPUB FB2

This paper describes an innovative approach for strengthening reinforced concrete slabs in shear with carbon fiber-reinforced polymer (CFRP) laminates. This paper describes an innovative approach for strengthening reinforced concrete slabs in shear with carbon fiber-reinforced polymer (CFRP) laminates.

A process analogous to stitching is used to retrofit concrete slabs with fiber-reinforced polymer (FRP) strands. Specimens were supported along their edges and tested to failure.

Strengthened slabs showed an increase in stiffness between 29 and 60% and in punching capacity between 6 and 16% with respect to the control unstrengthened slab. An analytical model was refined to predict the punching shear capacity of the specimens strengthened with CFRP strips.

In paper, the new and modern strengthening system of flat slabs against punching shear using screw anchors is presented. Screw anchors are installed from lower face of the slab into vertically drilled boreholes.

After the installation, the screw anchors operate as punching shear reinforcement. Four large scale slabs were tested; one slab was kept without strengthening and the other three slabs were strengthened with L-CFRP laminates using different configurations.

The behaviour of the slabs strengthened with L-CFRP laminates was compared with that of a similar slab without shear Cited by: 1. Research has been conducted on the effectiveness of strengthening flat slabs with CFRP sheets/laminates against punching shear failure.

Harajli and Soudki retrofitted flat slabs with CFRP sheets on the tension surface and reported that it improves the flexural and shear capacity by 17–45%. They suspected that the rise in load due to increased flexural capacity would change the failure mode from flexural to by: 2. These require strengthening in punching shear to safely carry the increased loading requirements.

In this paper, L CFRP laminates are explored for shear strengthening of RC flat slabs. FRP. Research has been conducted on the effectiveness of strengthening flat slabs with CFRP sheets/laminates against punching shear failure.

Harajli and Soudki retrofitted flat slabs with CFRP sheets on the tension surface and reported that it improves the flexural and shear capacity by 17 - 45%.

The experimental programme carried out by the authors includes four normal strength concrete slabs (×× mm3), with and without shear reinforcement, submitted to punching under a. This paper presents results of punching tests carried out in four reinforced concrete flat slabs, one of them without shear reinforcement and others strengthened with CFRP dowels.

Slabs were mm square meters and 60 mm thick and were subjected to mid span loadings until failure. The strengthening arrangements were radial and cruciform, varying the number of layers of CFRP dowels.

strengthening reinforced concrete slabs for punching shear using glass FRP (GFRP) laminates externally bonded to the concrete surface. They concluded that the GFRP laminates sig-nificantly increased the punching shear capacity of slab–col-umn connections because the laminates substantially functioned as external Size: 1MB.

Punching shear action has been a focus for research in the field of civil engineering and using a fiber-reinforced polymer (FRP) grid is a novel confi. of concrete beams can be increased by gluing CFRP laminates to the concrete web at locations of high shear stresses [3, 4].

Some research works dealt with the strengthening of one-way slabs using FRP materials in which slabs were treated in a very similar way to beams [5, 6]. Steel plates have been used in two-way slab punching shear. An analytical approach was conducted to calculate the punching shear strength of the slab-column connections strengthened with CFRP laminates.

Based on the theory of reinforced concrete members. This article reviews the literature on the methodology and effectiveness of utilizing FRP sheets/strips and laminates at the column/slab intersection to enhance punching shear strength of flat slabs. Reinforced concrete flat slabs or flat plates continue to be among the most popular floor systems due to speed of construction and inherent flexibility it offers in relation to locations of : Osama Ahmed Mohamed, Manish Kewalramani, Rania Khattab.

Esfahani et al., () studied the punching shear strengthening of flat slabs using CFRP sheets which were located at the tension side of the slabs. The test results showed that the use of CFRP sheets, in addition to steel reinforcing bars, as flexural reinforcement improves the punching shear strength of slabs.

The tensile strength of the CFRP laminate (composite) was limited to MPa, that is, the maximum resistance allowed by the Brazilian code for shear reinforcement.

Strengthening concrete slabs for punching shear with carbon fiber-reinforced polymer laminates. ACI. 50 ACI Structural Journal/January-February where V f is the shear force due to factored loads, d is the effective slab thickness for shear, and b o is the perimeter of the shear critical section d/2 from the column periphery.

According to the ACI standard,5 the nominal shear strength for a critical shear section d/2 from the column periphery is computed from the smallest of Size: KB.

Punching shear strengthening of flat-slabs with CFRP dowels Magazine of Concrete Research. ISSN | E-ISSN X. Volume 62 Issue 7, Julypp.

Prev Next > Punching shear strengthening of flat-slabs with CFRP dowels Authors: H. Erdogan * x. Erdogan. Search for articles by this author, B Cited by: 8. For the CFRP strengthened slabs, although there is a small increase in the first peak load (% for concrete grade A and % for concrete grade B) but the second peak load is significantly higher (% for concrete grade A and % for concrete grade B) as compared to the corresponding control slab.

For TRM Cited by: 6. It can be claimed that using FRP fans with epoxy resin for shear strengthening of concrete slabs is quite efficient due to the fixed end conditions of FRP fans. The results of this study were compared with punching shear predictions of concrete slabs based on JSCE and ACI by: The punching shear strength, stiffness, and mode of failure were investigated.

Test results demonstrated that increasing the compressive strength of concrete, ratio of the steel reinforcement, and amount of the CFRP laminates led to an increase in the punching shear strength of the slabs.

Moreover, the CFRP laminates were effective in. et al. [3] studied the punching shear strengthening of RC flat slabs using CFRP sheets located at the tension side of the slabs. They found that the punching shear strength of slabs can be increased by using of CFRP sheets, in addition to steel reinforcing bars, as flexural reinforcement.

Stark et al. [4]. 45 surface of RC slabs, while according to the NSM technique, CFRP laminates/rods are inserted into the grooves pre. 46 executed on the tensile surface of RC slabs. In both EBR and NSM techniques the CFRP systems are applied for the.

47 flexural strengthening. Slab specimens in the pilot test series (Sissakis ) were reinforced with short strands of CFRP laminate that were passed once through the holes cast in the slab and had their ends adhered to the top and bottom surface of the slab for anchorage [Fig.

2(a)].Large sheets of CFRP laminate were later installed on the top and bottom surface to ensure anchorage to the concrete as shown in Fig. 2(b). the punching-shear-strengthening specimens. FRP laminates and FRP strips were the main two materials used in this investigation.

FRP laminates were unidirectional glass fiber reinforced plastics (GFRP) that weighs g/m3. A layer of a cured FRP laminate is mm thick. FRP strips were pultruded carbon fibre reinforced plastics (CFRP) Size: KB. CFRP-STRENGTHENING - CONCRETE STRUCTURES STRENGTHENED WITH NEAR SURFACE MOUNTED CFRP LAMINATES Dr.

Prof. Täljsten Department of Civil Engineering, Luleå University of Technology, 87 Luleå, SWEDEN Skanska Teknik AB, 83 Solna, SWEDEN Abstract Rehabilitation and strengthening of existing concrete structures has come more and more in File Size: 2MB. The two punching strengthening methodologies herein investigated are schematically represented in Fig.

the execution of both techniques, mm diameter holes are drilled orthogonally to the middle plane of the RC slab, and CFRP wet layup sheets are inserted and bonded to the surrounding concrete substrate with an : Galileu S. Santos, Guilherme S.S.A.

Melo, Joaquim A.O. Barros. This study deals with a recent technique of flat slab strengthening against the punching phenomena, using CFRP sheets as shear resistant element. In the research, we compared the application of enshrined regulations in the technical environment with the experimental results of 39 slabs that simulate the area next to the internal columns of a.

This study investigates the punching shear strength and failure behavior of reinforced concrete slabs strengthened with glass fiber-reinforced polymer (GFRP) laminates.

The parameters of the 18 specimens studied herein are concrete compressive strength, steel reinforcement ratio, and the number of GFRP laminate layers. A NEW CFRP STRENGTHENING TECHNIQUE TO ENHANCE PUNCHING SHEAR STRENGTH OF RC SLAB-COLUMN CONNECTIONS H.

Erdoğan 1*, G. Özcebe 2 and B. Binici 2 1 Research Assistant, Department. of Civil Engineering, Kocaeli University, Turkey (Currently on leave at the Middle East Technical University for graduate study.High reinforcement ratios of external CFRP laminates can result in punching shear failure of slab–column connections subjected to eccentric concentrated loads.

STR-0 CON STR Sissakis, K.; Sheikh, S.A. Strengthening concrete slabs for punching shear with carbon fiber-reinforced polymer laminates. ACI Author: Osama Ahmed Mohamed, Manish Kewalramani, Rania Khattab.Strengthening Concrete Slabs for Punching Shear with Carbon Fiber-Reinforced Polymer Laminates.

Although research into the application of externally bonded fiber-reinforced polymers (FRPs) to reinforce concrete slabs has concentrated on improving flexural capacity, FRP laminates also offer the potential to improve the shear capacity of reinforced concrete slabs.