scholarly journals Shear Behaviour of RC Beams Strengthened by Various Ultrahigh Performance Fibre-Reinforced Concrete Systems

2020 ◽  
Vol 2020 ◽  
pp. 1-18 ◽  
Author(s):  
Walid Mansour ◽  
Bassam A. Tayeh
Keyword(s):  
Reinforced Concrete ◽  
Mechanical Performance ◽  
Experimental Studies ◽  
Element Model ◽  
Shear Behaviour ◽  
Fibre Reinforced Concrete ◽  
Rc Beams ◽  
Shear Span ◽  
Depth Ratio ◽  
Normal Strength

This study presents a numerical investigation on the shear behaviour of shear-strengthened reinforced concrete (RC) beams by using various ultrahigh performance fibre-reinforced concrete (UHPFRC) systems. The proposed 3D finite element model (FEM) was verified by comparing its results with those of experimental studies in the literature. The validated numerical model is used to analyse the crucial parameters, which are mainly related to the design of RC beams and shear-strengthened UHPFRC layers, such as the effect of shear span-to-depth ratio on the shear behaviour of the strengthened or nonstrengthened RC beams and the effect of geometry and length of UHPFRC layers. Moreover, the effect of the UHPFRC layers’ reinforcement ratio and strengthening of one longitudinal vertical face on the mechanical performance of RC beams strengthened in shear with UHPFRC layers is investigated. Results of the analysed beams show that the shear span-to-depth ratio significantly affects the shear behaviour of not only the normal-strength RC beams but also the RC beams strengthened with UHPFRC layers. However, the effect of shear span-to-depth ratio has not been considered in existing design code equations. Consequently, this study suggests two formulas to estimate the shear strength of normal-strength RC beams and UHPFRC-strengthened RC beams considering the effect of the shear span-to-depth ratio.

scholarly journals The Influence of CFRP Orientation Angle on the Shear Strength of RC Beams

2018 ◽  
Vol 12 (1) ◽  
pp. 269-281 ◽  
Author(s):  
Yasmin Murad
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Experimental Studies ◽  
Orientation Angle ◽  
Shear Behaviour ◽  
Experimental Program ◽  
Rc Beams ◽  
Cfrp Sheets ◽  
Reinforced Polymer ◽  
Cfrp Sheet

Background:Carbon Fiber Reinforced Polymer (CFRP) sheets are widely used for strengthening and repairing reinforced concrete structures. Previous experimental studies have shown that strengthening Reinforced Concrete (RC) beams with CFRP sheet can be greatly influenced by the configuration, orientation and properties of the CFRP sheets.Objective:The behaviour of RC beams, strengthened with 60° and 45° inclined CFRP sheets, has not clearly explained.Method:Thus, an experimental program, proposed in this paper, investigates the shear behaviour of RC beams strengthened with CFRP sheets under different orientation angles including 0˚, 45˚, 60˚ and 90˚.Result:The study shows that strengthening RC beams with CFRP is highly influenced by the orientation angle of the sheets. The influence of CFRP sheets is remarkable on increasing the ultimate deflection, ductility and shear strength of RC beams.Conclusion:It is beneficial to strengthen RC beams, which are weak in shear, obliquely using 45˚ or 60˚ inclined CFRP sheets.

SHEAR BEHAVIOR OF REINFORCED CONCRETE SLENDER BEAMS

2016 ◽  
Vol 3 (1) ◽  
Author(s):  
Muhammad K. Kayani ◽  
Wasim Khaliq ◽  
Muhammad K. Shehzad
Keyword(s):  
Reinforced Concrete ◽  
Shear Behavior ◽  
Shear Capacity ◽  
Experimental Program ◽  
Longitudinal Reinforcement ◽  
Rc Beams ◽  
Shear Reinforcement ◽  
Shear Span ◽  
Depth Ratio ◽  
Slender Beams

Major factors contributing to the shear behavior in reinforced concrete (RC) beams have been identified as compressive strength of concrete, shear span to effective depth ratio, and longitudinal reinforcement. Though significant, few of these factors are not fully incorporated in ACI code provisions for design of minimum shear reinforcement. To investigate the effect of these parameters, an analytical and experimental study was undertaken on the shear behavior of ordinary strength RC slender beams with moderate longitudinal reinforcement. The experimental program consisted of testing of eight simply supported RC slender beams subjected to two concentrated loads at a shear span to depth ratio (a/d) of 2.5 and equipped with varying shear reinforcement according to four different criteria. Ultimate shear strengths obtained in this experimental program are compared to the analytical shear strengths calculated according to existing as well as proposed equations. Test results exhibit that, the modified equation proposed in this work gives more accurate prediction of shear capacity of RC beams.

scholarly journals Mechanical Optimization of Concrete with Recycled PET Fibres Based on a Statistical-Experimental Study

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 240
Author(s):  
Alejandro Meza ◽  
Pablo Pujadas ◽  
Laura Montserrat Meza ◽  
Francesc Pardo-Bosch ◽  
Rubén D. López-Carreño
Keyword(s):  
Reinforced Concrete ◽  
Aspect Ratio ◽  
Mechanical Performance ◽  
Tensile Tests ◽  
Superior Performance ◽  
Fibre Reinforced Concrete ◽  
Marine Fauna ◽  
Recycled Pet ◽  
Pet Bottles ◽  
Fibre Aspect Ratio

Discarded polyethylene terephthalate (PET) bottles have damaged our ecosystem. Problems of marine fauna conservation and land fertility have been related to the disposal of these materials. Recycled fibre is an opportunity to reduce the levels of waste in the world and increase the mechanical performance of the concrete. PET as concrete reinforcement has demonstrated ductility and post-cracking strength. However, its performance could be optimized. This study considers a statistical-experimental analysis to evaluate recycled PET fibre reinforced concrete with various fibre dose and aspect ratio. 120 samples were experimented under workability, compressive, flexural, and splitting tensile tests. The results pointed out that the fibre dose has more influence on the responses than its fibre aspect ratio, with statistical relation on the tensional toughness, equivalent flexural strength ratio, volumetric weight, and the number of fibres. Moreover, the fibre aspect ratio has a statistical impact on the tensional toughness. In general, the data indicates that the optimal recycled PET fibre reinforced concrete generates a superior performance than control samples, with an improvement similar to those reinforced with virgin fibres.

Tensile basic creep versus compressive basic creep at early ages: comparison between normal strength concrete and a very high strength fibre reinforced concrete

2013 ◽  
Vol 47 (10) ◽  
pp. 1773-1785 ◽  
Author(s):  
Pierre Rossi ◽  
Jean Philippe Charron ◽  
Maléna Bastien-Masse ◽  
Jean-Louis Tailhan ◽  
Fabrice Le Maou ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
High Strength ◽  
Basic Creep ◽  
Fibre Reinforced Concrete ◽  
Normal Strength Concrete ◽  
Strength Concrete ◽  
Normal Strength ◽  
Very High

Finite Element Analysis of Shear Strength of Reinforced Concrete Beams after Fire

2013 ◽  
Vol 671-674 ◽  
pp. 474-478 ◽  
Author(s):  
Kai Xiang ◽  
Guo Hui Wang ◽  
Bi Zhao
Keyword(s):  
Finite Element ◽  
Shear Strength ◽  
Reinforced Concrete ◽  
Exposure Time ◽  
Concrete Strength ◽  
Reinforced Concrete Beams ◽  
Rc Beams ◽  
Fire Exposure ◽  
Shear Span ◽  
Strength And Stiffness

Shear strength and stiffness of fire-damaged reinforced concrete (RC) beams were researched. The nonlinear finite element method (FEM) was developed to simulate shear strength of fire-damaged RC beams. Considering mechanical properties deterioration of concrete and steel reinforcing bar, the parameters of fire-damaged RC beams, including fire exposure time, shear span to depth ratios, concrete strength, diameters of stirrups and spacing of stirrups, were analyzed. Based on numerical analysis, the change of shear strength and stiffness of fire-damaged RC beams were identified. The results showed that shear strength and stiffness of fire-damaged RC beams changed under different parameters. With increase of fire exposure time or increase of shear span to depth ratio or decrease of concrete strength, shear strength and stiffness of fire-damaged RC beams descended obviously. With decrease of diameters of stirrups or increase of spacing of stirrups, shear strength of fire-damaged RC beams descended gradually, but stiffness of fire-damaged RC beams had little change.

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