SHEAR BEHAVIOR OF RC BEAMS STRENGTHENED WITH DIFFERENT TYPES OF FRCM: EFFECT OF STIRRUPS’ CONFIGURATION

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Tadesse Wakjira ◽  
Usama Ebead
Keyword(s):  
Load Capacity ◽  
Shear Behavior ◽  
Shear Capacity ◽  
Rc Beams ◽  
Deep Beams ◽  
Shear Strengthening ◽  
Test Variable ◽  
Rc Deep Beams ◽  
Different Types ◽  
Primary Test

Fabric-reinforced cementitious matrix, (FRCM) system has shown to be promising for the strengthening of reinforced concrete (RC) beams. However, the available experimental investigation on the shear strengthening efficacy of FRCM system is limited, particularly for deep beams. Moreover, to the authors' knowledge, no literature is available on the effect of the stirrups' configuration relative to the FRCM strips on the shear capacity of FRCM-strengthened beams. Studying this effect will aid in a better understanding of the FRCM/stirrups interaction. Thus, in this paper the experimental study on the shear behavior of RC deep beams strengthened in shear using FRCM system is presented. The test matrix involved two unstrengthened and six FRCM-strengthened deep beams tested under three-point bending. The primary test variable was the effect of stirrups' configuration relative to the FRCM strips. The other test variable includes the effect of different types of FRCM fabric (made of carbon, glass, and polyparaphenylene benzobisoxazole, PBO). Experimental results demonstrated an effective application of the FRCM in improving the load capacities of RC deep beams, up to 40.3% increase in the load capacity was achieved.

scholarly journals Shear Behavior of Steel-Fiber-Reinforced Recycled Aggregate Concrete Deep Beams

Buildings ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 423
Author(s):  
Nancy Kachouh ◽  
Tamer El-Maaddawy ◽  
Hilal El-Hassan ◽  
Bilal El-Ariss
Keyword(s):  
Shear Behavior ◽  
Shear Capacity ◽  
Recycled Concrete ◽  
Recycled Aggregate Concrete ◽  
Steel Fibers ◽  
Recycled Aggregate ◽  
Shear Reinforcement ◽  
Deep Beams ◽  
Control Beam ◽  
Shear Response

Results of an experimental investigation aimed at studying the effect of steel fibers on the shear behavior of concrete deep beams made with a 100% recycled concrete aggregate (RCA) are presented in this paper. The study comprised testing of seven concrete deep beam specimens with a shear span-to-depth ratio (a/h) of 1.6. Two beams were made of natural aggregates (NAs) without steel fibers, two beams were made of a 100% RCA without steel fibers, and three beams were made of RCA-based concrete with steel fibers at volume fractions (vf) of 1, 2, and 3%. Two of the beams without steel fibers included a minimum shear reinforcement. Test results showed that the beam with a 100% RCA without steel fibers exhibited a lower post-cracking stiffness, reduced shear cracking load, and lower shear capacity than those of the NA-based control beam. The detrimental effect of the RCA on the shear response was less pronounced in the presence of the minimum shear reinforcement. The addition of steel fibers significantly improved the shear response of the RCA-based beams. The post-cracking stiffness of the RCA-based concrete beams with steel fibers coincided with that of a similar beam without fibers containing the minimum shear reinforcement. The use of steel fibers in RCA beams at vf of 1 and 2% restored 80 and 90% of the shear capacity, respectively, of a similar beam with the minimum shear reinforcement. The response of the RCA specimen with vf of 3% outperformed that of the NA-based control beam with the minimum shear reinforcement, indicating that steel fibers can be used in RCA deep beams as a substitution to the minimum shear reinforcement. The shear capacities obtained from the tests were compared with predictions of published analytical models.

scholarly journals Characterization and application of FRCM as a strengthening material for shear-critical RC beams

2018 ◽  
Vol 199 ◽  
pp. 09004
Author(s):  
Adel Younis ◽  
Usama Ebead
Keyword(s):  
Shear Capacity ◽  
Reinforced Concrete Beams ◽  
Rc Beams ◽  
Shear Strengthening ◽  
Structural Capacity ◽  
Test Parameters ◽  
Study Results ◽  
Glass Carbon ◽  
Characterization Test ◽  
Fabric Reinforced Cementitious Matrix

This paper investigates the effectiveness of fabric reinforced cementitious matrix (FRCM) systems in shear-strengthening of reinforced concrete beams. Three types of FRCM systems were considered, namely, polyparaphenylene benzobisoxazole (PBO)-FRCM, Carbon-FRCM, and Glass-FRCM. At first, tensile characterization test was performed on 15 FRCM coupons with the aim of identifying the tensile properties of the FRCM systems adopted. After that, seven shear-critical RC beams were tested under three-point loading, with the consideration of two test parameters: (a) FRCM material (glass/carbon/PBO); and (b) strengthening configuration (full/intermittent). The study results revealed the use of FRCM as a strengthening material to achieve a considerable improvement in the structural capacity of shear-critical RC beams. The average gain in the shear capacity of the FRCM-strengthened beams was 57%. The beam specimens strengthened with carbon-FRCM showed the highest improvement as compared to those strengthened with glass-and PBO-FRCM systems. As intuitively expected, the shear capacity improvement achieved with the full-length strengthening systems was generally higher than that with the intermittent counterparts.

scholarly journals Effect of shear span-to-depth ratio on the shear behavior of BFRP-RC deep beams

2017 ◽  
Vol 120 ◽  
pp. 01012 ◽  
Author(s):  
Siyam Alhamad ◽  
Yasser Al Banna ◽  
Ahmad Al Osman ◽  
Jihad Mouthassseeb ◽  
Suliman Abdalla ◽  
...  
Keyword(s):  
Shear Behavior ◽  
Deep Beams ◽  
Shear Span ◽  
Depth Ratio ◽  
Rc Deep Beams

Strengthening of shear deficient RC deep beams using GFRP sheets and mechanical anchors

2021 ◽  
Vol 48 (1) ◽  
pp. 1-15 ◽  
Author(s):  
A. Kumari ◽  
A.N. Nayak
Keyword(s):  
Design Guidelines ◽  
Shear Capacity ◽  
Deep Beams ◽  
Reinforced Polymer ◽  
Glass Fibre Reinforced Polymer ◽  
Rc Deep Beams ◽  
Externally Bonded ◽  
Fibre Reinforced Polymer ◽  
Glass Fibre Reinforced ◽  
Strengthened Beam

This paper presents the test results of an experimental study on shear deficient reinforced concrete (RC) deep beams strengthened with externally bonded glass fibre reinforced polymer (GFRP) sheets and mechanical anchors. A total of nine deep beams are prepared. One beam is kept as un-strengthened. Four beams are strengthened using GFRP sheets only at shear spans by varying the number of layers. The remaining four beams are strengthened using both GFRP sheets and mechanical anchors at shear spans. The shear capacity, failure mode, and deflections are studied with respect to the different strengthening techniques. The optimum enhancement in shear capacity of these beams is observed as 25.64% and 55.5% for GFRP strengthened beams and GFRP strengthened anchored beams, respectively with respect to the un-strengthened beam. Moreover, the experimental results are also compared with the results predicted from the design guidelines and models available in the literature, which shows good agreement.

Influence of Stirrup Corrosion on Shear Strength of RC Beams

2012 ◽  
Vol 204-208 ◽  
pp. 3287-3293
Author(s):  
Xin Xue ◽  
Hiroshi Seki ◽  
Yu Song
Keyword(s):  
Shear Strength ◽  
Mass Loss ◽  
Local Maximum ◽  
Shear Resistance ◽  
Shear Behavior ◽  
Shear Capacity ◽  
Maximum Mass ◽  
Rc Beams ◽  
Load Carrying ◽  
Maximum Mass Loss

There have been few reports on shear behavior of reinforced concrete (RC) beams with corroded stirrups, and the influence of stirrup corrosion has yet to be identified. Given this background, experience was carried out to investigate the shear behavior of RC beams containing corroded stirrups. Investigation results indicate that if the percentage local maximum mass loss is below 35%, there is little influence on the load-carrying mechanism. The concrete shear resistance seems to change little and the shear capacity can be calculated by just taking into consideration the reduction in stirrup shear resistance. It is also found that the anchorage conditions of the stirrups have a predominant influence on the shears of RC beams.

scholarly journals Shear behavior of reinforced concrete wide beams strengthened with CFRP sheet without stirrups

2019 ◽  
Vol 12 (1) ◽  
pp. 80-98
Author(s):  
Ali Laftah Abass
Keyword(s):  
Reinforced Concrete ◽  
Ultimate Load ◽  
Concrete Strength ◽  
Shear Behavior ◽  
Shear Capacity ◽  
Rc Beams ◽  
Shear Reinforcement ◽  
Control Beam ◽  
Cfrp Sheet ◽  
Wide Beams

Reinforced concrete wide beams (WBS) have been used in construction buildings because its provide many advantages; reducing the reinforcement congestion, reducing the quantity of the required formwork, providing simplicity for replication, and decreasing the storey height. The current study presents the results of four full-scale wide RC beams in order to study their shear behavior and investigate the effectiveness of carbon fiber reinforced polymer (CFRP) when using as shear reinforcement to improve the shear capacity of wide RC beams, one these beams was fabricated by (ANSYS) program this beam was unstrengthened with CFRP and without stirrups (control beam), the other two beams was strengthened with vertical and inclined CFRP sheet without stirrups and the last beam reinforced with shear stirrups (WBS). All beams casted with normal concrete strength (30 MPa), simply supported and under two point loads. The performances of these beams were measured in terms of; ultimate load, crack patterns, concrete and steel strains, deflection, and mode of failure. The results showed an increasing in ultimate load of strengthened beams with inclined, vertical CFRP and beam with shear reinforcement by (19.9%), (7.14%) and (39.8%) respectively as compared with the control beam, and this results means possibility of replacing the internal shear reinforcement with externally bonded CFRP.

scholarly journals Combined Flexural and Shear Strengthening of RC T-Beams with FRP and TRM: Experimental Study and Parametric Finite Element Analyses

Buildings ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 520
Author(s):  
Daniel A. Pohoryles ◽  
Jose Melo ◽  
Tiziana Rossetto
Keyword(s):  
Experimental Study ◽  
Finite Element ◽  
Shear Capacity ◽  
Fe Model ◽  
Rc Beams ◽  
Shear Strengthening ◽  
Flexural Strengthening ◽  
Existing Structures ◽  
The Difference ◽  
Reinforcement Design

Due to inadequacies of reinforcement design in older structures and changes in building codes, but also the change of building use in existing structures, reinforced concrete (RC) beams often require upgrading during building renovation. The combined shear and flexural strengthening with composite materials, fibre-reinforced polymer sheets (FRP) and textile reinforced mortars (TRM), is assessed in this study. An experimental campaign on twelve half-scale retrofitted RC beams is presented, looking at various parameters of interest, including the effect of the steel reinforcement ratio on the retrofit effectiveness, the amount of composite material used for strengthening and the effect of the shear span, as well as the difference in effectiveness of FRP and TRM in strengthening RC beams. Significant effects on the shear capacity of composite retrofitted beams are observed for all studied parameters. The experimental study is used as a basis for developing a detailed finite element (FE) model for RC beams strengthened with FRP. The results of the FE model are compared to the experimental results and used to design a parametric study to further study the effect of the investigated parameters on the retrofit effectiveness.

scholarly journals A Review on NSM-CFRP technique using in Shear Strengthening of RC Deep Beams

2019 ◽  
Vol 12 (36) ◽  
pp. 1-17 ◽  
Author(s):  
Mohanad Hatem ◽  
Abdul Aziz Abdul Samad ◽  
Noridah Mohamad ◽  
Goh Wan Inn ◽  
Saad Abdulqader
Keyword(s):  
Deep Beams ◽  
Shear Strengthening ◽  
Rc Deep Beams

FRCM SHEAR STRENGTHENING FOR CONCRETE BEAMS

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
Adel Younis ◽  
Usama Ebead ◽  
Kshitij C. Shrestha
Keyword(s):  
Shear Zone ◽  
Carbon Fibers ◽  
Shear Failure ◽  
Load Capacity ◽  
Full Length ◽  
Rc Beams ◽  
Test Results ◽  
Shear Strengthening ◽  
Strength Enhancement ◽  
Fabric Reinforced Cementitious Matrix

This paper presents the results of an experimental study carried out to examine the efficacy of Fabric-Reinforced Cementitious Matrix (FRCM) in strengthening RC beams susceptible to shear failure. In this paper, seven shear-critical RC beams, of 2,500 mm in length, 150 mm in width, and 330 mm in depth, were tested under three-point loading until failure. Two main test variables were considered, which are: a) Strengthening material: carbon, polyparaphenylene benzobisoxazole (PBO), or glass FRCM, and b) Strengthening application pattern: a single full-length FRCM plate or a set of intermittent and spaced FRCM strips were applied along the critical shear zone. The test results confirmed the efficacy of FRCM strengthening in improving the load capacity of shear-critical RC beams. The FRCM-strengthening contributed to increases in the load capacity ranged between 31% and 100% compared to the reference specimen. The full-length strengthened specimens generally showed a better strength enhancement compared to the intermittent counterparts when using the same FRCM material. Such intuitive observation assures the importance of the amount of strengthening material applied in the critical shear zone. Besides, specimens utilizing carbon fibers in its FRCM strengthening material showed the highest strength enhancement among the three systems.

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