scholarly journals Short-Term Flexural Stiffness Prediction of CFRP Bars Reinforced Coral Concrete Beams

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 467
Author(s):  
Lei Wang ◽  
Jin Yi ◽  
Jiwang Zhang ◽  
Wu Chen ◽  
Feng Fu
Keyword(s):  
Concrete Beam ◽  
Concrete Beams ◽  
Flexural Rigidity ◽  
Bending Stiffness ◽  
Reinforcement Ratio ◽  
Utilization Rate ◽  
Flexural Stiffness ◽  
Test Results ◽  
Short Term ◽  
Test Beam

FRP (Fiber Reinforced Polymer) Bar reinforced coral concrete beam is a new type of structural member that has been used more and more widely in marine engineering in recent years. In order to study and predict the flexural performance of CFRP reinforced coral concrete beams, the flexural rigidity, crack morphology and failure mode of concrete were studied in detail. The results show that under the condition of similar reinforcement ratio, the flexural rigidity of CFRP reinforced coral concrete beam is significantly lower than that of ordinary reinforced concrete beam. Increasing the cross-section reinforcement ratio within a certain range can increase the bending stiffness of the test beam or reduce the deflection, but the strength utilization rate of CFRP reinforcement is greatly reduced. The short-term bending stiffness of the CFRP reinforced coral concrete beam calculated by the existing standard formula is obviously higher. This paper proposes a modified formula for introducing the strain inhomogeneity coefficient (ψ) of CFRP bars and considers the relative slip between CFRP bars and coral concrete to predict the short-term flexural stiffness of coral concrete beams reinforced by CFRP bars. The formula was verified with the test results, and it was proved that the formula has a good consistency with the test results.

Experimental Study on Flexural Performances of Concrete Beams Strengthened with Near-Surface Mounted (NSM) FRP Reinforcement

2010 ◽  
Vol 163-167 ◽  
pp. 3634-3639
Author(s):  
Li Li Sui ◽  
Tie Jun Liu ◽  
Feng Xing ◽  
Yu Xiang Fu
Keyword(s):  
Experimental Study ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Flexural Stiffness ◽  
Test Results ◽  
Near Surface ◽  
Bending Performance ◽  
Bending Capacity ◽  
Frp Reinforcement ◽  
Near Surface Mounted

This paper illustrates the results of an experimental study on the bending performance of concrete beams strengthened with near-surface mounted (NSM) FRP reinforcement. The critical parameter of the embedded length of NSM-FRP plates was investigated in particularly. The test results indicated that NSM-FRP reinforcement can significantly improve the strength and crack resistance capacity of the concrete beam, reducing the size of cracks. The embedded length of the NSM-FRP plate has distinct influence on the cracking and bending capacity, the flexural stiffness, and the crack developments of the concrete beam. As the embedded length increased, the bending capacity and the flexural stiffness increased correspondingly and the crack developed more intensively.

scholarly journals Influence of stirrup spacing on shear resistance and deformation of reinforced concrete beams

2018 ◽  
Vol 7 (1) ◽  
pp. 126
Author(s):  
Latha M S ◽  
Revanasiddappa M ◽  
Naveen Kumar B M
Keyword(s):  
Concrete Beam ◽  
Concrete Beams ◽  
Bending Moment ◽  
Maximum Load ◽  
Reinforced Concrete Beams ◽  
Test Results ◽  
Cement Concrete ◽  
Simply Supported ◽  
Reinforced Cement ◽  
Flexural Reinforcement

An experimental investigation was carried out to study shear carrying capacity and ultimate flexural moment of reinforced cement concrete beam. Two series of simply supported beams were prepared by varying diameter and spacing of shear and flexural reinforcement. Beams of cross section 230 mm X 300 mm and length of 2000 mm. During testing, maximum load, first crack load, deflection of beams were recorded. Test results indicated that decreasing shear spacing and decreasing its diameter resulted in decrease in deflection of beam and increase in bending moment and shear force of beam.

Cracking behaviour of concrete beams reinforced with fiber reinforced plastic rebars

1996 ◽  
Vol 23 (6) ◽  
pp. 1172-1179 ◽  
Author(s):  
R. Masmoudi ◽  
B. Benmokrane ◽  
O. Chaallal
Keyword(s):  
Reinforced Concrete ◽  
Crack Width ◽  
Concrete Beams ◽  
Reinforcement Ratio ◽  
Test Results ◽  
Fiber Reinforced ◽  
Fiber Reinforced Plastic ◽  
Concrete Members ◽  
Reinforced Plastic ◽  
Cracking Pattern

This paper presents the results of an experimental investigation on the cracking behaviour of concrete beams reinforced with fiber reinforced plastic rebars. The effects of reinforcement ratio on the cracking pattern, crack spacing, cracking moment, and crack width are investigated. The test results indicate that the reinforcement ratio has no meaningful effect on the cracking moment, which can be calculated as recommended by the ACI code. Also, the use of the equations adopted by ACI and the European codes for the prediction of crack width of conventionally reinforced concrete members is investigated and due modifications are made. Both relationships show good correlation with the test results; and the prediction of crack width of concrete beams reinforced with these two types of fiber reinforced plastic rebars is now possible. Key words: beam, cracking behaviour, cracking moment, crack width, fiber reinforced plastic, flexure, rebars, reinforced concrete, reinforcement ratio.

Analysis of Bending Stiffness of Reinforced Concrete Beams Strengthened with Carbon Fiber Sheet

2012 ◽  
Vol 204-208 ◽  
pp. 2887-2890
Author(s):  
Yan Han ◽  
Hong Bo Liu ◽  
Tao Guo
Keyword(s):  
Reinforced Concrete ◽  
Carbon Fiber ◽  
Concrete Beams ◽  
Bending Stiffness ◽  
Reinforcement Ratio ◽  
Reinforced Concrete Beams ◽  
Fiber Layer ◽  
Fiber Sheet ◽  
Carbon Fiber Sheet

The stiffness of reinforced concrete simple beams strengthened with carbon fiber sheets is studied in this paper. The calculation formulas of it are discussed, for steel yielding and not yielding. The stiffness increases with the number of carbon fiber layer or reinforcement ratio increases.

scholarly journals Flexural Behavior of Bamboo Reinforced Concrete Beam with Steel Stirrups

2019 ◽  
Vol 8 (4S2) ◽  
pp. 97-99
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Reinforced Concrete Beam ◽  
Flexural Behavior ◽  
Test Results ◽  
Steel Reinforced Concrete ◽  
Beam Design ◽  
Materials Used ◽  
Bamboo Reinforcement

The flexural behavior of concrete beams reinforced with bamboo was studied experimentally. Bamboo was used as the main reinforcement with different bonding materials in place of steel. A nominal mix of M20 grade concrete was adopted for the beam design. The Bamboo surface was treated with common binding materials like Araldite and Bitumen. Araldite and Bitumen are good binding materials used to connect materials like steel, carbon and many different materials. Two specimens were casted with bitumen coating, two specimens were coated with araldite, two specimens were casted without any binder coating and a specimen was casted using normal steel reinforcement. Beams were casted with bamboo reinforcement and cured for 28 days. Deflection and flexural behavior of the beams were monitored. The test results imply that araldite coating in concrete beams with bamboo reinforcement increased the flexural strength to that of bamboo reinforced concrete using bitumen which is lesser strength to that of steel reinforced concrete beam.

Experimental Research on Ceramsite Concrete Beams

2012 ◽  
Vol 166-169 ◽  
pp. 708-711
Author(s):  
Chuang Du ◽  
Wen Ling Tian ◽  
Xiao Wei Wang ◽  
De Jun Wang
Keyword(s):  
Concrete Beam ◽  
Ultimate Load ◽  
Concrete Beams ◽  
Polypropylene Fiber ◽  
Flexural Behavior ◽  
Polypropylene Fibers ◽  
Test Results ◽  
Normal Concrete ◽  
Ordinary Concrete ◽  
Cover Thickness

Six specimens, including 4 ceramsite concrete beams(one of beams mixed into the polypropylene fiber ) and 2 normal concrete beams, were tested to investigate the flexural behavior. The test results show that cracking load of ceramsite concrete beams is slightly smaller than the ordinary concrete beam and cracking load of ceramsite concrete beams has significantly improved after mixing into the polypropylene fibers. The ultimate load of ceramsite concrete beams are no less than ordinary concrete beam,and fibers have not effects on the increase of ultimate load. Load-deflection curves were compared,and the results show that stiffness of ceramsite concrete beam is less than ordinary concrete beam. Ductility of ceramsite concrete beam is poorer than ordinary concrete beam. Fibers improve the stiffness of ceramsite concrete beam. Cover thickness of concrete beam has little effect on the performance of ceramsite concrete beam.

Estimation of Ultimate Tendon Stress in Reinforced Concrete Beams Prestressed with External FRP Tendons

2013 ◽  
Vol 798-799 ◽  
pp. 374-377
Author(s):  
Shuan Jiang
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Plastic Hinge ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Beams ◽  
Test Results ◽  
Stress Increment ◽  
Hinge Zone ◽  
Good Agreement

The ultimate tendon stress is the key to calculation of flexural capacity in reinforced concrete beam prestressed with external FRP tendons (RCBPEFT). Based on the theory of equivalent plastic hinge zone, the general formulas for calculating the ultimate tendon stress increment and ultimate tendon stress in RCBPEFT are therefore proposed. Comparisons indicate that the predictions are in good agreement with the test results.

Deflection Calculation on Reinforced Concrete Beams Strengthened by Externally Prestressing Transverse Tensioning Method

2013 ◽  
Vol 671-674 ◽  
pp. 430-436
Author(s):  
Jin Jun Liu ◽  
Tian Wen Wang
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Large Error ◽  
Reinforced Concrete Beams ◽  
Secondary Effect ◽  
Test Results ◽  
Short Term ◽  
Secondary Load ◽  
Externally Prestressing ◽  
Good Agreement

Eight reinforced concrete beams (six externally reinforced and two contrast beams) were tested under primary or secondary load experiment. According to the test results, the existing specifications were applied to make calculations on short-term deflection which leaded to a large error. The secondary effect should be considered on calculating the deflection. Therefore, comparisons were made between the improved calculated value and test value on deflections of reinforced concrete beams strengthened by externally prestressed transverse tensioning method and they are in good agreement.

Theoretical Analysis of Natural Vibration Frequency for Unbonded Prestressed Concrete Beams

2012 ◽  
Vol 594-597 ◽  
pp. 882-885 ◽  
Author(s):  
Feng Ge Li ◽  
Rong Li
Keyword(s):  
Prestressed Concrete ◽  
Natural Frequencies ◽  
Concrete Beams ◽  
Flexural Rigidity ◽  
Variable Stiffness ◽  
Natural Vibration Frequency ◽  
Test Results ◽  
Unbonded Tendons ◽  
Proposed Model ◽  
Calculation Results

This papers deals with the study of the influence of prestress force on the natural frequencies for unbonded prestressed concrete beams. A total of 5 unbounded prestressed concrete simply support beams were constructed and tested. The test results show that the prestress force has little effect on the nature frequencies of unbonded prestressed concrete beams. A model of variable stiffness is proposed to calculate the natural frequencies of prestressed concrete beams with unbonded tendons, which assumed that the flexural rigidity of the beam is changing when beams vibrating. The calculate results show that the calculation results by the proposed model agree well with experimental ones.

scholarly journals EXPERIMENTAL LOAD-DRIFT RELATIONS OF CONCRETE BEAM REINFORCED AND CONFINED WITH HIGH-STRENGTH STEEL BARS UNDER REVERSED CYCLIC LOADING

2021 ◽  
Vol 11 (4) ◽  
pp. 56-69
Author(s):  
Retno Anggraini ◽  
Tavio Tavio ◽  
Gusti Putu Raka ◽  
Agustiar Agustiar
Keyword(s):  
Reinforced Concrete ◽  
High Strength Steel ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Concrete Strength ◽  
High Strength ◽  
Reinforced Concrete Beams ◽  
Test Results ◽  
Steel Bars ◽  
Normal Strength

High-strength steel bars have different characteristics from normal-strength steel bars. Thus, the use of high-strength steel bars still needs to be investigated further before it can be used confidently in concrete structures. In the design, a reinforced concrete beam should also have enough ductility besides its loading capacity. One of the indicators identifies that a structure has sufficient ductility is its ability to maintain the load steadily due to progressive deformation. This paper presents the test results of three reinforced concrete beams designed with concrete strength (fc) of 30 MPa. Two different yield strengths (fy) of longitudinal and transverse reinforcements were used, namely, 420 and 550 MPa. The cross-sectional dimensions of the beams were 200  300 mm with a total span of 2000 mm and a rigid stub at the midspan. The beams were simply supported by double rollers at their tops and bottoms. These special supports were located at both ends of the beams. The load applied at the midspan of the beam through the rigid stub with the displacement control. The loading pattern protocol by the drift was set from 0 to 5.5 percent. Based on the test results, it can be seen that the beams with high-strength steel bars could achieve a higher load capacity than the beams with normal-strength steel bars. On the other hand, the beams with high-strength steel bars produced lower deflection than the beams with normal-strength steel bars. Furthermore, it can be concluded that all the beams could withstand the minimum required of 3.5 percent. None of the beams indicated brittle failures. All of the beams could survived until the end of the cycles at a drift of 5.5 percent. This condition indicates that the reinforced concrete beams with higher-strength reinforcement (fy of 550 MPa) could also maintain their load capacities under large deformation beyond the first yielding of the longitudinal steel bars.

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