Theoretical Analysis on Flexural Behavior of Concrete Members Reinforced by Steel-Basalt FRP Composite Bars

2014 ◽  
Vol 578-579 ◽  
pp. 236-239
Author(s):  
Tong Liang Xiao ◽  
Hong Xing Qiu
Keyword(s):  
Bearing Capacity ◽  
Longitudinal Direction ◽  
Flexural Behavior ◽  
Longitudinal Reinforcement ◽  
Flexural Members ◽  
Concrete Members ◽  
Frp Composite ◽  
Flexural Member ◽  
The Moment ◽  
Corrosive Resistance

Steel-Basalt FRP Composite Bar (S-BFCB) is a new kind of substitute material for longitudinal reinforcement, with high elastic modulus, stable post-yield stiffness and excellent corrosive resistance. It is made up of steel wrapped by basalt FRP in longitudinal direction. Based on mechanical properties of S-BFCB and the plane cross-section assumption, the moment-curvature relationship and stiffness on flexural members at different stages have been analyzed and verified by experiment. Flexural member reinforced by S-BFCB can make full use of the strength of FRP. By the principle of equivalent bar stiffness, the results show that the curvature and stiffness are almost the same results at pre-yield stage. While after yield, flexural member reinforced by S-BFCB has stable secondary stiffness and high bearing capacity. With the increase of fiber, the ultimate bearing capacity is improved.

scholarly journals Experimental Ductility of Compression-Controlled Flexural Members Using CFRP Grid to Confine Concrete

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5163
Author(s):  
Antonis Michael ◽  
H. R. Hamilton
Keyword(s):  
Flexural Behavior ◽  
Compression Zone ◽  
Flexural Members ◽  
Control Beam ◽  
Brittle Behavior ◽  
Concrete Members ◽  
Flexural Failure ◽  
Frp Composite ◽  
Concrete Confinement ◽  
Grid Reinforcement

Concrete members are typically designed so that flexural failure initiates with steel yielding and ends with concrete crushing in compression in order to take advantage of the yielding property of steel that allows for large deformations prior to any fracture of the material. On the other hand, if a large percentage of steel or linear elastic non-yielding reinforcement (i.e., FRP composite) is used, the member flexural failure typically initiates and ends with concrete crushing in compression. These members are known as compression-controlled members and typically exhibit brittle behavior. This study proposes a new approach in improving the flexural behavior of over-reinforced members through concrete confinement using carbon fiber reinforced polymer (CFRP) grid tubes in the compression zone. The concept was experimentally tested using rectangular beams. Beam 1 (control beam) had no grid reinforcement and beam 2 (tube beam) had two 152 mm grid tubes embedded in its compression zone. Experimental results indicate improvement in the ductility of the tube beam compared to the control beam of approximately 20–30% depending on the criteria used. Considering the low amount and mechanical properties of the CFRP grid, the improvement is significant, which shows that the proposed approach is valid and improves the ductility of compression-controlled members.

scholarly journals Moment-Curvature Behaviors of Concrete Beams Singly Reinforced by Steel-FRP Composite Bars

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Zeyang Sun ◽  
Yang Yang ◽  
Wenlong Yan ◽  
Gang Wu ◽  
Xiaoyuan He
Keyword(s):  
Bearing Capacity ◽  
Concrete Beams ◽  
Reinforcement Ratio ◽  
Frp Composite ◽  
Steel Bar ◽  
Before And After ◽  
Frp Bar ◽  
Deformation Ability ◽  
Effective Depth ◽  
The Moment

A steel-fiber-reinforced polymer (FRP) composite bar (SFCB) is a kind of rebar with inner steel bar wrapped by FRP, which can achieve a better anticorrosion performance than that of ordinary steel bar. The high ultimate strength of FRP can also provide a significant increase in load bearing capacity. Based on the adequate simulation of the load-displacement behaviors of concrete beams reinforced by SFCBs, a parametric analysis of the moment-curvature behaviors of concrete beams that are singly reinforced by SFCB was conducted. The critical reinforcement ratio for differentiating the beam’s failure mode was presented, and the concept of the maximum possible peak curvature (MPPC) was proposed. After the ultimate curvature reached MPPC, it decreased with an increase in the postyield stiffness ratio (rsf), and the theoretical calculation method about the curvatures before and after the MPPC was derived. The influence of the reinforcement ratio, effective depth, and FRP ultimate strain on the ultimate point was studied by the dimensionless moment and curvature. By calculating the envelope area under the moment-curvature curve, the energy ductility index can obtain a balance between the bearing capacity and the deformation ability. This paper can provide a reference for the design of concrete beams that are reinforced by SFCB or hybrid steel bar/FRP bar.

Deformation Behavior of Reinforced Concrete Members with Prefabricated Fiber Laminate Composites

2007 ◽  
Vol 345-346 ◽  
pp. 1245-1248
Author(s):  
Young Gyun Hong ◽  
Gi Sub Hong ◽  
Jae Kyu Kang ◽  
Kyu Hong Hwang ◽  
Jeong Bae Yoon
Keyword(s):  
Quality Control ◽  
Deformation Behavior ◽  
Experimental Investigations ◽  
Control Group ◽  
Laminate Composites ◽  
Flexural Members ◽  
Concrete Members ◽  
Innovative Method ◽  
Flexural Member ◽  
Strengthening Method

The innovative method based on prefabricated fiber laminate composites bonded to lightweight precast panel was applied for quality control of RC strengthening members. The experimental investigations for this method were presented for flexural member. Three different groups such as control group without strengthening, conventional fiber bonding group and innovated PFLC group bonded to precast panel. Tested results showed good or better capacities comparing to conventional strengthening method for flexural members. This investigation indicate that good enhancement with respect to quality control and reliability can be possible by the installation and epoxy injection with prefabricated panel using fiber laminate composites.

Failure Mechanism and Analysis of Reinforced Concrete Members with Fiber-Steel Laminate Composites

2007 ◽  
Vol 345-346 ◽  
pp. 677-680
Author(s):  
Jeong Bae Yoon ◽  
Ji Hye Choi ◽  
Young Gyun Hong ◽  
Sang Ho Ahn ◽  
Jung Hyun Park
Keyword(s):  
Reinforced Concrete ◽  
Failure Modes ◽  
Steel Plate ◽  
Fiber Material ◽  
Control Group ◽  
Laminate Composites ◽  
Flexural Members ◽  
Concrete Members ◽  
Flexural Member ◽  
Fiber Materials

The new composite method combined by fiber laminates and steel plate composites was applied for reinforced concrete members. The experimental investigation for the applicability of this method was presented for flexural member. Two different fiber materials such as carbon and fiberglass with steel plate were used. All specimen using fiber material and steel plate were divided by two different groups such as control group without strengthening, innovated fiber-steel laminate composites group. Failure modes and load-deflection curves were presented for flexural members by fiber-steel laminate composites. Numerical analysis for tested beam was investigated.

scholarly journals Experimental Study on the Flexural Behavior of an Innovative Modular Steel Building Connection with Installed Bolts in the Columns

2019 ◽  
Vol 9 (17) ◽  
pp. 3468 ◽  
Author(s):  
Yongrui Wang ◽  
Junwu Xia ◽  
Renwei Ma ◽  
Bo Xu ◽  
Tonglei Wang
Keyword(s):  
Bearing Capacity ◽  
Static Loading ◽  
Bending Moment ◽  
Flexural Behavior ◽  
Destruction Process ◽  
Load Bearing Capacity ◽  
Welding Seam ◽  
Steel Building ◽  
Loading Tests ◽  
The Moment

Modular buildings have the highest levels of precasting in the current building system. There are some defects in present modular connections, such as the difficulties of construction, the weakening of the bearing capacity of beams or columns, and damage to decorations. This paper presents an innovative modular connection with installed bolts in the columns. Two symmetrical monotonous static loading tests were conducted to explore the flexural behavior of the innovative connection. Meanwhile, the moment–rotation relations, destruction process, ultimate bearing capacity, stiffness classification and internal stress distribution were analyzed. The results showed that the specimen S1 with smaller diagonal stiffeners lost its bearing capacity due to the failure of the welding seam, and the extreme moment was 169 kN·m. The failure mode of S2 with large diagonal stiffeners was beam buckling, and the extreme moment was 209 kN·m. The stress of diagonal stiffeners and the join between the upper beam and stiffeners increased rapidly. Stiffeners can increase the stiffness and load-bearing capacity. The connection failures occurred on the beam or beam–column joints, while the connection between modules remained undamaged, which showed that the new connection has a good bearing capacity under the action of bending moment and pressure.

A Method for Checking Eccentricity of Solid Concrete Piers with Low Longitudinal Reinforcement Ratio under a Minor Earthquake

2014 ◽  
Vol 580-583 ◽  
pp. 1515-1520
Author(s):  
Xing Chong Chen ◽  
Zun Wen Liu ◽  
Yong Liang Zhang ◽  
Lu Pei
Keyword(s):  
Bearing Capacity ◽  
High Speed ◽  
Reinforcement Ratio ◽  
Longitudinal Reinforcement ◽  
Allowable Stress ◽  
High Speed Railway ◽  
The Moment ◽  
A Minor

Solid concrete piers with low longitudinal reinforcement ratio are extensively used in high-speed railway in China. However, how to check such structures is not specified in current technical codes. Checking these structures by eccentricity and stress indexes is discussed hereby. The moment-curvature relationships for piers of various reinforcement ratios are presented by employing the software UCfyber and these moments are compared with moments calculated by allowable stress approach, moments corresponding to the code-specified permissible eccentricity, moments corresponding to the allowable reinforcement stress and stabilizing moments induced by tensile reinforcement and self-weight of the piers, respectively. The results show that the allowable stress approach could be used to check the strength and eccentricity of solid concrete piers with low longitudinal reinforcement ratio in high-speed railway; the restriction on permissible eccentricity may be to a proper extent relaxed for such piers, based on the fact that tensile reinforcement provides an additional stabilizing moment and the reinforcement contributes to the pier’s bearing capacity.

Flexural Behavior of CFRP Strengthened Reinforced Concrete Beams

2013 ◽  
Vol 477-478 ◽  
pp. 740-743
Author(s):  
Hui Zhang ◽  
Hong Sheng Wu ◽  
Xing Quan Li
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Fiber Reinforced Polymer ◽  
Flexural Behavior ◽  
Experimental Result ◽  
Reinforced Polymer ◽  
Flexural Member ◽  
Good Agreement

In order to clear the influence of carbon fiber reinforced polymer (CFRP) on the bearing capacity of reinforced concrete beams, tests of three reinforced concrete beams strengthened with CFRP are carried out. Experimental result shows that CFRP can effectively increase bearing capacity of flexural member, and can restrain the development of crack. Cracking load, yield load and ultimate load are significantly increased. At the same time numerical simulation is done; it is good agreement with experimental results.

Susceptibility of strain-hardening cementitious composite to curing conditions as a retrofitting material for RC beams

2021 ◽  
Vol 16 ◽  
pp. 155892502110203
Author(s):  
Mohammad Iqbal Khan ◽  
Galal Fares ◽  
Yassir Mohammed Abbas ◽  
Wasim Abbass ◽  
Sardar Umer Sial
Keyword(s):  
Strain Hardening ◽  
Environmental Conditions ◽  
Carrying Capacity ◽  
Flexural Behavior ◽  
Load Carrying Capacity ◽  
Rc Beams ◽  
Curing Conditions ◽  
Flexural Members ◽  
Load Carrying ◽  
Curing Regime

Strain-hardening cement-based composites (SHCC) have recently been developed as repair materials for the improvement of crack control and strength of flexural members. This work focuses on strengthening and flexural enhancement using SHCC layer in tensile regions of flexural members under three different curing conditions. The curing conditions simulate the effect of different environmental conditions prevailing in the central and coastal regions of the Arabian Peninsula on the properties of SHCC as a retrofitting material. In this investigation, beams with SHCC layer were compared to control beams. The beams with SHCC layer of 50-mm thickness were cast. The results revealed that the flexural behavior and the load-carrying capacity of the normal concrete beam specimens under hot and dry environmental conditions were significantly reduced, lowering the ductility of the section. However, compressive strength is comparatively unaffected. Similarly, the hot curing conditions have also led to a notable reduction in the loading capacity of the beam with SHCC layer with a slight effect on its stiffness. On the other hand, steam-curing conditions have shown improvement in load-carrying capacity and a reduction in section ductility of the beam with SHCC layer. It was found that the structural unit retrofitted with SHCC layer was a curing-regime dependent as the tensile and strain-hardening properties of SHCC are highly sensitive to the alteration in the cement hydration process. A normal curing regime was found effective and satisfying the practical, cost, and performance requirements. Accordingly, a normal curing regime could be implemented to retrofit reinforced concrete (RC) beams with SHCC layers as recommended in the study.

Durability of concrete members reinforced with steel-FRP composite bars under dry-wet cycles of seawater

Structures ◽  
2021 ◽  
Vol 33 ◽  
pp. 2273-2283
Author(s):  
Lining Ding ◽  
Mengke Lei ◽  
Xin Wang ◽  
Yuwei Shi ◽  
Zhongguo Zhu ◽  
...  
Keyword(s):  
Concrete Members ◽  
Frp Composite ◽  
Durability Of Concrete

Research on Shear Bearing Capacity of Reinforced Concrete Short Beam in Salt-Fog Environment

2012 ◽  
Vol 455-456 ◽  
pp. 1079-1083
Author(s):  
Wei Jun Yang ◽  
Hong Jia Huang ◽  
Wen Yu Jiang ◽  
Yi Bin Peng
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Salt Spray ◽  
Test Chamber ◽  
Shear Capacity ◽  
Salt Spray Test ◽  
Concrete Members ◽  
Short Beam ◽  
Shear Bearing Capacity ◽  
Salt Fog

Shantou atmospheric salt-fog environment is simulated with the comprehensive salt spray test chamber. By using reinforced concrete short beams under different water-cement radio, different corrosion time, the inclined section degradation rules of the corrosive reinforced concrete members are researched for establishing shear capacity of short beam formulas in salt-fog environment.

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