scholarly journals Impact Behavior of Composite Reinforced Concrete Beams with Pultruded I-GFRP Beam

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 441
Author(s):  
Teghreed H. Ibrahim ◽  
Abbas A. Allawi ◽  
Ayman El-Zohairy
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Impact Loading ◽  
Static Loading ◽  
Reinforced Concrete Beams ◽  
Impact Behavior ◽  
Drop Height ◽  
Concrete Compressive Strength ◽  
Shear Connectors ◽  
The Impact

The present study experimentally and numerically investigated the impact behavior of composite reinforced concrete (RC) beams with the pultruded I-GFRP and I-steel beams. Eight specimens of two groups were cast in different configurations. The first group consisted of four specimens and was tested under static load to provide reference results for the second group. The four specimens in the second group were tested first under impact loading and then static loading to determine the residual static strengths of the impacted specimens. The test variables considered the type of encased I-section (steel and GFRP), presence of shear connectors, and drop height during impact tests. A mass of 42.5 kg was dropped on the top surface at the mid-span of the tested beams from five different heights: 250, 500, 1000, 1500, and 1900 mm. Moreover, nonlinear Finite Element (FE) models were developed and validated using the experimental data. Static loading was defined as a displacement-controlled loading and the impact loading was modeled as dynamic explicit analysis with different drop velocities. The validated models were used to conduct a parametric study to investigate the effect of the concrete compressive strength on the performance of the composite beams under static and impact loadings. For the composite specimen with steel I-sction, the maximum impact force was 190% greater than the reference specimen NR-I at a drop height of 1900 mm, whereas the maximum impact forces for the specimens composite specimens with GFRP I-sction without and with shear connectors were 19% and 77%, respectively, more significant than the reference beam at the same drop height. The high stiffness for the steel I-beams relative to the GFRP I-beam was the reason for this difference in behavior. The concrete compressive strength was more effective in improving the impact behavior of the composite specimens relative to those without GFRP I-beams.

scholarly journals Torsional Strengthening of Reinforced Concrete Beams with Externally-Bonded Fibre Reinforced Polymer: An Energy Absorption Evaluation

2020 ◽  
Vol 6 ◽  
pp. 69-85
Author(s):  
Mahir M. Hason ◽  
Ammar N. Hanoon ◽  
Ahmed W. Al Zand ◽  
Ali A. Abdulhameed ◽  
Ali O. Al-Sulttani
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Energy Absorption ◽  
Structural Damage ◽  
Absorption Capacity ◽  
Reinforced Concrete Beams ◽  
Rc Beams ◽  
Concrete Compressive Strength ◽  
Externally Bonded ◽  
The Impact

The impacts of numerous important factors on the Energy Absorption (EA) of torsional Reinforced Concrete (RC) beams strengthened with external FRP is the main purpose and innovation of the current research. A total of 81 datasets were collected from previous studies, focused on the investigation of EA behaviour. The impact of nine different parameters on the Torsional EA of RC-beams was examined and evaluated, namely the concrete compressive strength (f’c), steel yield strength (fy), FRP thickness (tFRP), width-to-depth of the beam section (b/h), horizontal (ρh) and vertical (ρv) steel ratio, angle of twist (θu), ultimate torque (Tu), and FRP ultimate strength (fy-FRP). For the evaluation of the energy absorption capacity at different levels, Response Surface Methodology (RSM) was implemented in this study. Also, to fit the measured results, Quadratic and Line models were created. The results show that the RSM technique is a highly significant tool that can be applied not only to energy absorption-related problems examined in this research, but also to other engineering problems. An agreement is observed between Pareto and standardized charts with the literature showing that the EA capacity of the torsional FRP-RC beams is mostly affected by the concrete compressive strength, followed by the vertical reinforcement ratio. The newly suggested model in this article exhibits a satisfactory correlation co-efficient (R), of about 80%, with an adequate level of accuracy. The obtained results also reveal that the EA acts as a safety index for the FRP-strengthened RC beams exposed to torsional loadings to avoid sudden structural damage. Doi: 10.28991/cej-2020-SP(EMCE)-07 Full Text: PDF

Guidelines for flexural design of FRP reinforced concrete beams

2020 ◽  
pp. 002199832097373
Author(s):  
Fares Jnaid
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Carrying Capacity ◽  
Concrete Beams ◽  
Large Diameter ◽  
Reinforced Concrete Beams ◽  
Load Carrying Capacity ◽  
Concrete Compressive Strength ◽  
Load Carrying ◽  
Multiple Variables

This paper investigates the effects of different parameters on the live load carrying capacity of concrete beams reinforced with FRP bars. The author performed a parametric study utilizing an innovative numerical approach to inspect the effects of multiple variables such as reinforcement ratio, concrete compressive strength, span to depth ratio, FRP type, and bar diameter on load carrying capacity of FRP reinforced concrete beams. This study concluded that unless the span to height ratio is smaller than 8, tension-controlled sections are impractical as they do not meet code requirements for serviceability. In addition, it is recommended to use higher reinforcement ratios when using larger span to depth ratios and/or when using CFRP reinforcing bars. Moreover, larger number of bars with small diameter is more practical than fewer large diameter bars. Furthermore, this research suggests that increasing the concrete compressive strength is associated with a significant increase in the ultimate flexural capacity of FRP reinforced beams.

Influence of Minimum Tension Steel Reinforcement on the Behavior of Singly Reinforced Concrete Beams in Flexure

2020 ◽  
Vol 38 (7A) ◽  
pp. 1034-1046
Author(s):  
Ali ِA. Abdulsada ◽  
Raid I. Khalel ◽  
Kaiss F. Sarsam
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Concrete Beams ◽  
Rectangular Cross Section ◽  
Steel Reinforcement ◽  
Reinforced Concrete Beams ◽  
Concrete Compressive Strength ◽  
Minimum Reinforcement ◽  
Flexural Reinforcement ◽  
New Formula

The requirements of minimum flexural reinforcement in the last decades have been a reason for controversy. The structural behavior of beams in bending is the best way of investigating and evaluating the minimum reinforcement in flexure. For this purpose, twelve singly reinforced concrete beams with a rectangular cross-section of (125 mm) width by (250 mm) height and (1800 mm) length were cast and tested under two-point loads up to failure. These beams were divided into three groups with different compressive strengths (25, 50, and 80 MPa). Each group consists of four beams with different amounts of tension steel reinforcement approximately equal to (0% Asmin, 50% Asmin, 100% Asmin and 150% Asmin), two bar diameters (Ø6 mm and Ø8 mm) were used as the longitudinal tension reinforcement with different yield and ultimate strengths, the minimum amount of reinforcement required is calculated based on ACI 318M-2014 code. The results show that for the reinforced concrete beams, the flexural reinforcement in NSC beams increases the first cracking load and the increment increased with an increasing amount of reinforcement, while for HSC beams the increasing in first cracking load are very little when the quantity of reinforcement less than the minimum flexural reinforcement and increased with the increasing amount above the minimum flexural reinforcement. The equation of ACI 318M-14 code gives adequate minimum flexural reinforcement for NSC and overestimate value for HSC up to (83 MPa), A new formula is proposed for HSC rectangular beams up to (90 MPa) concrete compressive strength by reducing the equation of ACI 318M-14 code for minimum flexural reinforcement by a factor depending on concrete compressive strength.  

Experimental and numerical study of reinforced concrete beams with steel fibers subjected to impact loading

2017 ◽  
Vol 27 (7) ◽  
pp. 1058-1083 ◽  
Author(s):  
Liu Jin ◽  
Renbo Zhang ◽  
Guoqin Dou ◽  
Jiandong Xu ◽  
Xiuli Du
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Impact Loading ◽  
Impact Force ◽  
Numerical Study ◽  
Reaction Force ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Reinforced Concrete Beams ◽  
The Impact

As a kind of impact resistant material, steel fiber reinforced concrete (SFRC) has a good ductility and energy dissipation capacity by improving the tensile strength and impact toughness. To explore the dynamic mechanical behavior of SFRC beams subjected to impact loading, 12 simply-supported SFRC beams with different stirrup ratios (0%, 0.253% and 0.502%) and different volume fractions of steel fibers (0%, 1%, 2% and 3%) were tested with free-falling drop-weights impacting at the mid-span of specimens. The failure patterns were observed and videoed, and simultaneously, the time histories of the impact force, the reaction force, and the mid-span deflection were recorded. Moreover, the influences of stirrup ratio and volume fraction of steel fibers on the impact resistant behavior of the SFRC beams were preliminarily analyzed and discussed. The results indicate that the impact resistant performance of SFRC beams, such as crack pattern, ductility, energy consumption capacity, and deformation recovery capacity can be improved by the addition of steel fibers and stirrups. The required static capacity of these beams were calculated based on the analysis of reaction force vs. displacement loop and impact force vs. displacement loop as well as absorbed energy ratio. For further understanding the experimental results, finite element simulation of SFRC beams subjected to impact loading were carried out. The rationality and accuracy of the finite element model was illustrated by the good agreement between the test observations and the numerical results.

scholarly journals Behavior and strength of reinforced reactive powder concrete beams under impact loadings

2018 ◽  
Vol 7 (4) ◽  
pp. 2753
Author(s):  
Ibtihal Fadhil ◽  
Ayad K. Kadhem ◽  
Nisreen Salih
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Steel Fiber ◽  
Concrete Beams ◽  
Impact Load ◽  
Experimental Tests ◽  
Reinforced Concrete Beams ◽  
Reactive Powder Concrete ◽  
Reactive Powder ◽  
The Impact

Reactive powder concrete is a new concrete that has been used in recent years because of many advantages. The use of reactive powder concrete in structural elements such as beams provides higher compressive strength, higher modulus of elasticity, durable concrete and increasing the concrete ductility, so that the concrete has high resistance against tensile stress. The experimental tests of the reinforced concrete beams under the effects of impact loadings are investigated in this paper. The parameters being adopted in present paper are steel fiber of (1, 1.5 and 2%) by volume, dropped mass and height of drop. The reinforced concrete specimens were tested under impact load by one strike only. The test results indicate that the impact force increased when the compressive strength of concrete increased that when the steel fiber ratio becomes more and the deflection has become less.  

Impact Resistance of Post-Tensioned Concrete

1990 ◽  
Vol 211 ◽  
Author(s):  
Nianzhi Wang ◽  
Sidney Mindess
Keyword(s):  
Reinforced Concrete ◽  
Impact Loading ◽  
Concrete Beams ◽  
Impact Resistance ◽  
Plain Concrete ◽  
Reinforced Concrete Beams ◽  
Fibre Reinforced Concrete ◽  
Impact Tests ◽  
The Impact ◽  
Post Tensioned

AbstractImpact tests were carried out on post-tensioned beams, prepared both with plain concrete and fibre-reinforced concrete. It was found that post-tensioned beams might be less resistant to impact loading than were ordinary reinforced concrete beams. However, the addition of fibres to the concrete greatly increased the impact resistance of these beams.

scholarly journals Effect of CFRP Shear Strengthening on the Flexural Performance of the RC Specimen under Unequal Impact Loading

2020 ◽  
Vol 2020 ◽  
pp. 1-18
Author(s):  
Yanhui Liu ◽  
Khalil Al-Bukhaiti ◽  
Hussein Abas ◽  
Zhao Shichun
Keyword(s):  
Reinforced Concrete ◽  
Impact Loading ◽  
Shear Failure ◽  
Impact Load ◽  
Concrete Strength ◽  
Impact Behavior ◽  
Parameter Study ◽  
Dynamic Amplification Factor ◽  
Flexural Performance ◽  
The Impact

Strengthening with externally bonded CFRP reinforcement is widely used in structural reinforcement and attractive to stakeholders and engineers because of ease and speed of construction, corrosion resistance, lightweight, high strength, and versatility stiffness which can be oriented according to the need. Numerous research studies were carried out to explore RC beams’ flexural and shear performance when subjected to dynamic impact loading. The results were auspicious in using such a technique of strengthening. Regular square section reinforced concrete frame members strengthened by CFRP material is taken as the research object. However, little attention to the impact behavior of CFRP-shear-strengthened square reinforced concrete (RC) specimens has been paid. The dynamic response of CFRP to reinforced concrete members under unequal cross-impact is discussed. This paper investigates the effectiveness of CFRP strengthening on the square RC specimen in preventing shear failure and evaluation of the flexural performance of the strengthened specimen under the impact load. The drop hammer impact test is firstly conducted on RC specimens with and without CFRP strengthening. The results show that using CFRP to strengthen the RC specimen in shear is very effective at preventing shear failure and leading the specimen’s response to flexural domination. This result is also the motivation for developing a numerical model supported by experimental tests to study the flexural performance of strengthened RC specimens. It is found that the strengthened specimen is prone to exhibit pure bending deformation under the impact load in terms of dynamic amplification factor (DAF) for section moment. Then, an extensive parameter study is carried out to evaluate further the influence of impact velocity, reinforcement ratio, and concrete strength on the flexural performance of the strengthened specimen and CFRP layers. Such a holistic study may provide preliminary research regarding the use of CFRP to strengthen RC specimens in shear under impact loads and will enhance the current state of knowledge in this area; also, the optimal value of the CFRP reinforcement layer was proposed.

scholarly journals Experimental investigation of Low velocity impact response of reinforced concrete beams without stirrups

2018 ◽  
Vol 183 ◽  
pp. 02038
Author(s):  
Yingqian Fu ◽  
Xinlu Yu ◽  
Xinlong Dong ◽  
Fenghua Zhou
Keyword(s):  
Reinforced Concrete ◽  
Impact Loading ◽  
Concrete Beam ◽  
Shear Failure ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Low Velocity Impact ◽  
Experimental Program ◽  
Failure Model ◽  
The Impact

This paper presents an experimental program of reinforced concrete beam without stirrups tested by impact three-point-bending under different initial velocity (drop height). As the results shown, for the static events, the failure mode is bending firstly, and then translates to shearing. the longitudinal reinforcements play an important role for the increasing of loading during bending stage. For the impact events, reinforced concrete beams failed in a flexural failure model at slow rates of loading and in shear failure model at high impact loading rate relatively. Moreover, the shear failure and bending failure have developed during the peak stage of Force-deflection curves. That is different with the emergence sequence of cracks under static tests. So the mechanical parameters of peak stage should be considered for the resistance of concrete beam under impact loading.

Simulation of Flexural Behavior of Reinforced Concrete Beams under Impact Loading

2013 ◽  
Vol 351-352 ◽  
pp. 1018-1023
Author(s):  
Arnaud Rouchette ◽  
Wei Ping Zhang ◽  
Hui Chen
Keyword(s):  
Reinforced Concrete ◽  
Strain Rate ◽  
Impact Loading ◽  
Concrete Beams ◽  
Kinematic Model ◽  
Experimental Results ◽  
Reinforced Concrete Beams ◽  
Flexural Behavior ◽  
Bond Model ◽  
The Impact

This paper focuses on the numerical simulation of the flexural behavior of reinforced concrete beams under impact loading by the LS-DYNA finite element code. An enhanced version of the Concrete Damage Model Release 3 (K&C) was used for the concrete materials and a Plastic Kinematic Model was adopted for steel reinforcement, both material models used parameters to cope with the effects of strain rate. The simulation also took the bond between concrete and steel bar into consideration, and its behavior model was based on high strain rate experimental results. The simulation of the mid span drop tests, both with and without bond consideration, were compared to experimental results to investigate the influence of bond consideration and the reliability of the overall simulation model. Compared with experimental results, the calculated mid-span deflections with the bond model agreed much better than those without the bond model, and a simplified formulation was drawn from the trend on deformation depending on the impact velocity.

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