scholarly journals Flexural Behavior of T-Shaped UHPC Beams with Varying Longitudinal Reinforcement Ratios

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5706
Author(s):  
Rui Zhang ◽  
Peng Hu ◽  
Kedao Chen ◽  
Xi Li ◽  
Xiaosen Yang
Keyword(s):  
Compressive Strength ◽  
Reduction Factor ◽  
Reinforced Concrete Beams ◽  
Flexural Behavior ◽  
Experimental Result ◽  
Longitudinal Reinforcement ◽  
Flexural Capacity ◽  
Tension And Compression ◽  
Ductile Behavior ◽  
Material Tests

In order to investigate the transverse flexural behavior of the UHPC waffle deck, a total of six T-shaped UHPC beams, with varying longitudinal reinforcement ratios, were tested and analyzed. The experiments, including material tests of UHPC and beam tests, were conducted. The material tests of UHPC revealed that strain-hardening behavior in tension was exhibited, and the ratio of uniaxial compressive strength-to-cubic compressive strength was 0.85. The beam tests showed that all the T-shaped UHPC beams, even without longitudinal rebar, exhibited ductile behavior that was similar to that of properly reinforced concrete beams. As the longitudinal reinforcement ratio increased, more flexural cracks developed and a larger load-carrying capacity was provided. Furthermore, the sectional analysis for the ultimate flexural capacity of T-shaped UHPC beams was conducted. Simplified material models, under tension and compression, for UHPC were developed. Based on the reverse calculation from the experimental result, the relation between reduction factor to the ultimate tensile strength of UHPC, and longitudinal reinforcement ratios was formulated. As a result, the predictive equations for the ultimate flexural capacity of T-shaped UHPC beams were proposed, and agreed well with the experimental results in this study and existing studies, which indicates good validity of the proposed equations.

Influence of Nano Particles in the Flexural Behavior of High-Strength Reinforced Concrete Beams

2021 ◽  
Vol 1160 ◽  
pp. 25-43
Author(s):  
Naglaa Glal-Eldin Fahmy ◽  
Rasha El-Mashery ◽  
Rabiee Ali Sadeek ◽  
L.M. Abd El-Hafaz
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
High Strength Concrete ◽  
High Strength ◽  
Reinforced Concrete Beams ◽  
Nano Particles ◽  
Flexural Behavior ◽  
Single Type ◽  
Strength Concrete ◽  
Flexural Ductility

High strength concrete (HSC) characterized by high compressive strength but lower ductility compared to normal strength concrete. This low ductility limits the benefit of using HSC in building safe structures. Nanomaterials have gained increased attention because of their improvement of mechanical properties of concrete. In this paper we present an experimental study of the flexural behavior of reinforced beams composed of high-strength concrete and nanomaterials. Eight simply supported rectangular beams were fabricated with identical geometries and reinforcements, and then tested under two third-point loads. The study investigated the concrete compressive strength (50 and 75 N/mm2) as a function of the type of nanomaterial (nanosilica, nanotitanium and nanosilica/nanotitanium hybrid) and the nanomaterial concentration (0%, 0.5% and 1.0%). The experimental results showed that nano particles can be very effective in improving compressive and tensile strength of HSC, nanotitanium is more effective than nanosilica in compressive strength. Also, binary usage of hybrid mixture (nanosilica + nanotitanium) had a remarkable improvement appearing in compressive and tensile strength than using the same percentage of single type of nanomaterials used separately. The reduction in flexural ductility due to the use of higher strength concrete can be compensated by adding nanomaterials. The percentage of concentration, concrete grade and the type of nanomaterials, could predominantly affect the flexural behavior of HSRC beams.

scholarly journals Ductility Estimation of Concrete Beams Longitudinally Reinforced with Hybrid FRP-Steel Bars

2022 ◽  
Author(s):  
Rendy Thamrin ◽  
Zaidir Zaidir ◽  
Devitasari Iwanda
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Element Model ◽  
Neutral Axis ◽  
Reinforced Concrete Beams ◽  
Flexural Behavior ◽  
Bending Test ◽  
Longitudinal Reinforcement ◽  
Steel Bars ◽  
Hybrid Reinforcement

An experimental study was carried out to evaluate the ductility of reinforced concrete beams longitudinally reinforced with hybrid FRP-Steel bars. The specimens were fourteen reinforced concrete beams with and without hybrid reinforcement. The test variables were bars position, the ratio of longitudinal reinforcement, and the type of FRP bars. The beams were loaded up to failure using a four-point bending test. The performance of the tested beams was observed using the load-deflection curve obtained from the test. Numerical analysis using the fiber element model was used to examine the growth of neutral axis depth due to the effect of test variables. The neutral axis curves were then used to further estimate the neutral axis angle and neutral axis displacement index. The test results show that the position of the reinforcement greatly influences the flexural behavior of the beam with hybrid reinforcement. It was observed from the test that the flexural capacity of beams with hybrid reinforcement is 4% to 50% higher than that of the beams with conventional steel bars depending on bars position and the ratio of longitudinal reinforcement. The ductility decreases as the hybrid reinforcement ratio (Af/As) increases. This study also showed that a numerical model developed can predict the flexural behavior of beams with hybrid reinforcement with reasonable accuracy.

The Flexural Performance of Pre-Damaged Reinforced Concrete Beam Strengthened with CFRP in Seawater Environment

2012 ◽  
Vol 166-169 ◽  
pp. 1736-1739
Author(s):  
Yu Tian Wang ◽  
Xiu Li Du ◽  
Fu Xiang Jiang ◽  
Wei Zhang
Keyword(s):  
Reinforced Concrete ◽  
Failure Modes ◽  
Concrete Beams ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Beams ◽  
Flexural Behavior ◽  
Strengthening Effect ◽  
Flexural Capacity ◽  
Flexural Performance ◽  
Seawater Environment

Experiments on flexural behavior of strengthened pre-damaged reinforced concrete beams with CFRP and those exposed to seawater for different time have been carried out. By comparison, the rule of seawater effecting on failure modes of beams, fissure condition, strain development and flexural capacity, and so on have been studied. The results show that reinforcement treatment on the mechanical damaged reinforced concrete beams with bonding CFRP can effectively improve their flexural capacity and stiffness, and constrain the development of cracks. With the extension of time under seawater environment, although performance of pre-damaged beam strengthened with CFRP is influenced significantly, the strengthening effect is still more reliable.

Study on the Recycled Concrete Beam’s Stiffness

2012 ◽  
Vol 193-194 ◽  
pp. 1361-1364
Author(s):  
Fang Yu ◽  
Can Bin Yin ◽  
Min Jiang
Keyword(s):  
Compressive Strength ◽  
Concrete Beam ◽  
Recycled Concrete ◽  
Flexural Behavior ◽  
Flexural Capacity ◽  
Replacement Ratio ◽  
Normal Section ◽  
Simply Supported ◽  
Axial Compressive Strength ◽  
Ultimate Moment

The intent of this paper is to investigate the flexural behavior of 4 recycled concrete simply-supported beams with same percentage of reinforntage of reinforcement and axial compressive strength but different replacement ratio of recycled aggregates.Besides the flexural capacity of normal section,the characteristics of both deflection and cracking are analyzed.Based on the experiment results,the following conclusions are drawn.In bending,the recycled concrete beam also has elastic,cracking,yield and ultimate point.The ultimate moment of recycled concrete beam can be estimated by the formula suggested by present code.

scholarly journals Finite element modeling of flexural behavior of reinforced concrete beams externally strengthened with CFRP sheets

2021 ◽  
Vol 16 (59) ◽  
pp. 62-77
Author(s):  
Mahmoud Madqour ◽  
Khalid Fawzi ◽  
Hilal Hassan
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Concrete Beams ◽  
Element Model ◽  
Point Load ◽  
Reinforced Concrete Beams ◽  
Flexural Behavior ◽  
Flexural Capacity ◽  
Cfrp Sheets ◽  
Cfrp Sheet

In this research, the finite element method is used to develop a numerical model to analyse the effect of the external strengthening of reinforced concrete beams by using carbon Fiber Reinforced Polymer (CFRP) sheets. A finite element model has been developed to investigate the behavior of RC beams strengthened with CFRP sheets by testing nineteen externally simple R.C. beams, tested under a four-point load setup until failure. Various CFRP systems were used to strengthen the specimens.  The numerical results using the (ANSYS workbench v.19.1) were calibrated and validated with the experimental results.  The research results indicate a significant improvement in the structural behavior of the specimens strengthened using CFRP sheet systems. Then the validated model investigated the effect of the width of CFRP sheets, no of layers, and CFRP size on the behavior of strengthened R.C. beams. Results of this numerical investigation show the effectiveness of increase CFRP width to improve the flexural capacity of R.C. beams. An increase in the flexural capacity up to 100 % compared to the control beam.

An Experimental Study on Flexural Behavior of Reinforced Concrete Beams Strengthened with High-Performance Ferrocement

2010 ◽  
Vol 163-167 ◽  
pp. 3772-3776 ◽  
Author(s):  
Hua Ping Liao ◽  
Shi Sheng Fang
Keyword(s):  
Reinforced Concrete ◽  
Comparative Analysis ◽  
High Performance ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Flexural Behavior ◽  
Rc Beams ◽  
Test Results ◽  
Flexural Capacity ◽  
Engineering Designs

Three reinforced concrete (RC) beams strengthened by high-performance ferrocement and two control specimens without strengthened are investigated when RC beams have low compressive strength. Flexural behaviors of strengthened RC beams with high-performance ferrocement are evaluated based on comparative analysis with RC beams. The strengthening results of steel meshes with U-shape (i.e. ferrocements are put onto the tension face and two profile faces) are analyzed. The flexural capacity, deflection and crack width of RC flexural beams are measured, and then comparative analysis is carried out for deformation performance and law of crack development. The test results show that ferrocement contributes greatly to increase the flexural capacity and raise crack-resisting capacity. The experimental results can provide a theoretical reference for actual engineering designs.

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