Study on the Deflection Behavior of HRBF RC Beams under Serviceability Limit States

2014 ◽  
Vol 638-640 ◽  
pp. 265-269
Author(s):  
Wen Jie Ge ◽  
Bi Yuan Wang ◽  
Da Fu Cao
Keyword(s):  
Bearing Capacity ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Capacity Utilization ◽  
High Strength ◽  
Bending Test ◽  
Limit States ◽  
Utilization Coefficient ◽  
Hot Rolled ◽  
Current Code

In order to investigate the deflection behavior of concrete beam reinforced with high strength hot rolled bars of fine grains (HRBF) under deflection control condition, four concrete beams reinforced with HRBF400 and HRBF500 rectangle cross-section concrete beam static bending test were made. The results show that Mid-span deflection of concrete beams reinforced with HRBF400 under normal conditions still meets the requirement of current code while concrete beams reinforced with HRBF500 could not meets the requirement. Mid-span deflection was calculated by current code and compared with experimental value, the results show that calculate value was a little bigger than experimental value and tend to be safe, deflection could still calculated by the current code. Bearing capacity calculates formula under the conditions of deflection control was proposed, conception of component’s bearing capacity utilization coefficient (BCUC) was put forward. Effects of reinforcement strength, concrete grade, reinforcement ratio and depth-span ratio on BCUC were analyzed.

Construction Technology Research of RC Beams Strengthened with Prestressed CFRP Plates

2011 ◽  
Vol 268-270 ◽  
pp. 659-663
Author(s):  
Hua Chen ◽  
Kan Kang ◽  
Lang Ni Deng
Keyword(s):  
Crack Resistance ◽  
Concrete Beams ◽  
High Strength ◽  
The Self ◽  
Bending Test ◽  
Construction Technology ◽  
Rc Beams ◽  
Test Results ◽  
Technology Research ◽  
Flexural Capacity

The method of applying prestress to CFRP plates can make full use of the characteristics of high-strength, enhance the force properties, prevent peeling damage and reduce the strain lag. Construction technology of prestressed CFRP plates strengthening reinforcement concrete beams was introduce in this paper, and bending test of 6 reinforcement concrete beams strengthened with prestressed CFRP plates were carried out based on the self-developed prestressed CFRP plates supporting anchorages. The test results indicate that the flexural capacity and crack resistance capacity can be increased compared with non-prestressed CFRP plates, and the construction technology can be adopted in practical projects.

Composite action in masonry walls under vertical in-plane loading: experimental results compared with predictions

2015 ◽  
Vol 42 (7) ◽  
pp. 449-462
Author(s):  
A.T. Vermeltfoort ◽  
D.R.W. Martens
Keyword(s):  
Bearing Capacity ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Compressive Force ◽  
Reinforced Concrete Beams ◽  
Elastic Behavior ◽  
Masonry Walls ◽  
Load Bearing Capacity ◽  
Cracking Behavior ◽  
Load Bearing

The results of five experimental test series on masonry walls supported by reinforced concrete beams or slabs are reported and compared to theoretical predictions of the load bearing capacity. The experiments were performed on deep masonry beams built with respectively calcium silicate and clay brick. Investigated parameters were: position of the supports, concrete beam-masonry interface, concrete beam stiffness, type of loading, and height of masonry wall and concrete beam. Based on literature, the method proposed by Davies and Ahmed as well as the method according to Eurocode 6 were used to estimate the load bearing capacity of the tested masonry walls supported by concrete beams. The method of Davies and Ahmed allows for the determination of the stresses and stress resultants in the masonry. The analysis shows that near the support an inclined compressive force acts at the bed joint, which means that a shear-compression stress state exists in the bed joint. Strength evaluation has been carried out using the Mann-Müller criterion that is adopted in Eurocode 6. Based on the test results, it may be concluded that both methods yield conservative values of the load bearing capacity, as could be expected. Before cracking a linear elastic behavior was observed, while after cracking a strut-and-tie model may be applied. To develop more accurate design models, it is recommended to investigate the post-cracking behavior in more detail.

scholarly journals Debonding Detection and Monitoring for CFRP Reinforced Concrete Beams Using Pizeoceramic Sensors

Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2150 ◽  
Author(s):  
Shukui Liu ◽  
Wei Sun ◽  
Hongwen Jing ◽  
Zhaoxing Dong
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Low Cost ◽  
Ultrasonic Waves ◽  
Reinforced Concrete Beams ◽  
Bending Test ◽  
Cfrp Sheet ◽  
Debonding Detection

The bonding status between Carbon Fiber Reinforced Polymer (CFRP) and concrete is one of the key issues for the safety of CFPR-reinforced structures, thus it is of great importance to detect the debonding as early as possible. Instead of detecting the debonding which is artificially set at the very beginning, this paper investigates the feasibility of using low-cost piezoceramic sensors to detect and monitor the debonding of CFRP-reinforced concrete beams in situ. For existing debonding detection, a concrete beam reinforced with CFRP sheet was loaded through the three-point bending test till failure to induce debonding between CFRP sheet and the concrete substrate, and piezoceramic sensors were used to detect the existing debonding by analyzing the receiving ultrasonic waves. In addition, the debonding detection results were further compared with and verified by the vision-based strain testing results. For in-situ debonding monitoring, 10 piezoceramic sensors were used as an array to track the wave transmission changes during the loading process of a CFRP-reinforced concrete beam, and the debonding development process was successfully monitored. The test results show that the low-cost piezoceramic sensors are very effective to generate and receive ultrasonic waves, and are capable of detecting the existing debonding and monitoring of the in-situ debonding process as well.

scholarly journals Flexural Behavior of Post-Tensioned Concrete Beams with Multiple Internal Corroded Strands

2020 ◽  
Vol 10 (22) ◽  
pp. 7994
Author(s):  
Chi-Ho Jeon ◽  
Chang-Su Shim
Keyword(s):  
Prestressed Concrete ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Safety Issue ◽  
Material Model ◽  
Flexural Behavior ◽  
Bending Test ◽  
Material Models ◽  
Strain Compatibility ◽  
Prestressed Concrete Beam

The corrosion of prestressing steel in prestressed concrete bridges is a critical safety issue. To evaluate the strength of a prestressed concrete beam with corroded strands, it is necessary to know the mechanical properties of the corroded strands in terms of their tensile strength and ductility. In this study, material models were suggested using tensile tests of corroded strands which had been taken from existing bridges. Five prestressed concrete beams with multiple internal corroded strands of different corrosion levels and locations were fabricated and tested using the three-point bending test. The beams with corroded strands near the support did not show meaningful flexural behavior changes, while the beams with corrosion in the mid-span showed significant strength reduction. In order to suggest the appropriate evaluation of the flexural strength of a prestressed concrete beam with corroded strands, material models of the corroded strands were divided into two model categories: a bi-linear material model and a brittle material model. Strength evaluations of the corroded prestressed concrete beams according to fps approximation and strain-compatibility using OpenSEES were conducted. Results suggested the use of the strain compatibility method only when the section loss was greater than 5%.

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.

Research on Flexural Behaviors of Cementitious Composite Material Formwork without Being Removed Concrete Beams

2010 ◽  
Vol 163-167 ◽  
pp. 2047-2051 ◽  
Author(s):  
Shuang Xi Zhou
Keyword(s):  
Bearing Capacity ◽  
Concrete Beam ◽  
Normal Concrete ◽  
Ordinary Concrete ◽  
Failure Patterns ◽  
Limit Value ◽  
Monotonic Loads ◽  
Flexural Beam ◽  
Deflection Limit ◽  
Current Code

Based on experiments on two beam specimens (one is a concrete beam with a formwork without demoulding, another is a normal concrete beam), the basic mechanical properties of the flexural beam with a formwork without demoulding, in the condition of monotonic loads were studied, including failure patterns, normal section bearing capacities, change rules of deflections, concrete strain of midspan, strain of strengthened reinforcing steer and so on. The comparison of bearing capacity is also made between a concrete beam with a formwork without demoulding and an ordinary concrete beam. The results indicate that by calculating bend-bearing capacity in current code, a beam with a formwork without demoulding is as safe as an ordinary concrete beam, a concrete beam with a formwork without demoulding meets the requirements of deflection limit value. Its bend-bearing capacity is approximate to an ordinary concrete beam.

Experimental Study on Flexural Bearing Capacity of Reinforced Ceramsite Concrete Beam

2011 ◽  
Vol 366 ◽  
pp. 253-257
Author(s):  
Wei Jun Yang ◽  
Zheng Bo Pi ◽  
Zhen Lin Mo
Keyword(s):  
Bearing Capacity ◽  
Concrete Beam ◽  
Failure Modes ◽  
Concrete Beams ◽  
Cement Mortar ◽  
Reinforced Concrete Beams ◽  
Ordinary Concrete ◽  
Steel Bar ◽  
Steel Bars ◽  
Flexural Bearing Capacity

In order to investigate the flexural bearing capacity of reinforced ceramic concrete beams, static loading experiments were carried out. 10 ceramic reinforced concrete beams and 2 non-reinforced ceramic concrete with different steel ratios, cover thicknesses and bar diameters were fabricated. The gauges of concrete was arraged on the surfaces of section in mid-span and and steel gauges was arraged on the surfaces of steel bars. The loading device was consisted of a 200kN hydraulic jack, a distributive girder and reaction frame while the dial indicators was arraged in supports and mid-span. The strain of concrete and steel bar in different loading along with the crack,yield and utimate of load were recorded .It found that the stress-strain law, crack extension regularity , failure modes of specimens was similar to the ordinary concrete beams and the current procedures formulas about flexural bearing capacity is reliability. It also found that both ceramic aggregate and cement mortar were crushed for the perfectly bonding of the interface and the strength of aggregate was to be fully utilized.

Test Research on Stiffness of Loaded Concrete Beams Strengthened with Prestressed CFRP Sheets

2013 ◽  
Vol 690-693 ◽  
pp. 752-755
Author(s):  
Dong Hui Cheng ◽  
Peng Zhang
Keyword(s):  
Mechanical Properties ◽  
Bearing Capacity ◽  
Test Data ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Cfrp Sheets ◽  
Capacity Limit ◽  
Reinforced Beams ◽  
Prestressed Cfrp Sheets ◽  
Load Conditions

In order to investigate the mechanical properties of concrete beams strengthened with CFRP sheets under load conditions, according to the reinforcement ratio, three groups of twelve concrete beams were made, each group included an common concrete beam and three prestressed CFRP sheets reinforced beams. Then the test with two-point loading was completed and the test date were obtained. On the basis of the test data, load state of concrete beams strengthened with prestressed CFRP sheets can effectively improve the ultimate bearing capacity, limit crack development and ameliorate the section stiffness.

scholarly journals ANALISIS ELEMEN HINGGA NONLINIER BALOK GESER BETON MEMADAT MANDIRI DAN BETON MUTU TINGGI

Teras Jurnal ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 375
Author(s):  
Mahmud Kori Effendi ◽  
Novi Rahmayanti
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
High Strength Concrete ◽  
Concrete Beam ◽  
Concrete Beams ◽  
High Strength ◽  
Self Compacting Concrete ◽  
Strength Concrete ◽  
Mechanical Compaction ◽  
Von Mises

<p align="center"><strong>Abstrak</strong></p><p class="11daftarpustaka"> </p><p class="11daftarpustaka">Indonesia merupakan negara yang rentan terhadap bencana gempa bumi. Banyak rumah atau gedung di Indonesia dibangun dengan menggunakan material beton bertulang. Kerusakan geser pada elemen beton bertulang tersebut sangat berbahaya, hal ini dikarenakan kerusakan ini terjadi secara tiba-tiba dan biasanya terjadi secara eksplosif. Analisis nonlinier elemen hingga tiga dimensi balok beton memadat mandiri dan beton mutu tinggi dengan pemadatan mekanis dilakukan dengan software MSC Marc/Mentat. Baja dimodelkan dengan tertanam di beton. Kriteria kegagalan Linier Mohr-Coulomb digunakan untuk beton dan Von Mises untuk baja tulangan. Hasil kurva hubungan beban-lendutan untuk kedua balok beton memadat mandiri dan beton mutu tinggi pemadatan mekanis hampir sama dengan hasil kurva eksperimen di daerah elastic, namun setelah melewati fase elastik, kurva analisis berbeda sedikit dengan kurva eksperimen. Hasil analisis teoritis kekuatan beton hampir sama dengan hasil analisis elemen hingga balok beton tanpa tulangan. Hasil analisis kontak juga memperlihatkan terjadi kontak dan perlepasan pada bidang kontak baja tumpuan beban dan tumpuan balok dengan beton.</p><p class="11daftarpustaka"> </p><p class="11daftarpustaka">Kata kunci: <em>beton memadat mandiri,</em><em> mutu tinggi, elemen hingga, MSC Marc/Mentat</em><em></em></p><p class="11daftarpustaka"> </p><p align="center"><strong> </strong></p><p align="center"><strong>Abstract</strong></p><p class="11daftarpustaka"> </p><p class="11daftarpustaka">Indonesia is a country that is prone to earthquakes. Many houses or buildings in Indonesia are built using reinforced concrete material. Shear damage to reinforced concrete elements is very dangerous, because this damage occurs suddenly and usually occurs explosively. The nonlinear three-dimensional finite element analysis of self-compacting concrete beam and high strength concrete beam by mechanical compaction were carried out using the MSC Marc/Mentat software. Steel is modeled by being embedded in concrete. The Mohr-Coulomb Linear failure criterion is used for concrete and Von Mises for reinforcing steel. The results of the load- deflection curves for both self-compacting and mechanical compaction high-strength concrete beams are almost the same as those of the experimental curves in the elastic area, after elasticity, the analysis curve differs slightly from the experimental curve. The results of the theoretical analysis of the strength of the concrete are almost the same as the results of the analysis of the finite element concrete beams without reinforcement. The results of the contact analysis also showed that there was contact and detachment in the contact area of the load bearing steel and the beam support with the concrete.</p><p class="11daftarpustaka"> </p><p class="11daftarpustaka">Keywords: <em>self-compacting concrete, high strength, finite element, MSC Marc/Mentat</em><em></em></p>

Experimental Research on Flexural Behavior of Load-Bearing Characteristics on Reinfoeced Concrete Beams Strengthened with near Surface Mounted Prestressed CFRP Tendons

2011 ◽  
Vol 94-96 ◽  
pp. 1415-1419
Author(s):  
Ping Xu ◽  
Min Xia Zhang ◽  
Ya Hong Ding ◽  
Xing Guo Wang
Keyword(s):  
Concrete Beams ◽  
High Strength ◽  
Concrete Surface ◽  
Flexural Behavior ◽  
Bending Test ◽  
Near Surface ◽  
Load Bearing ◽  
Strength Performance ◽  
Near Surface Mounted ◽  
Different Levels

In order to improve flexural behavior of concrete beams, the 7mm-diameter carbon fiber reinforced plastic (CFRP) tendons applied different levels of prestress were put in to 20×20mm grooves opened in the concrete surface of the tensile region in the concrete beams.Grooves were filled with building structural adhesive, when it solidified bending test of strengthened beams would carry out. Flexural behavior of nine RC beams strengthened with prestressed near surface mounted CFRP tendons applied different levels of prestress and one unstrengthened RC beam were studied. In these tests, bending stiffness and load-bearing characteristics of test specimens were studied. Experimental results show that the high-strength performance of CFRP have been made full use; the stiffness of strengthened beams risen notably, the maximal crack load increased by 303.17%, the maximal ultimate load increased by 237.92%.

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