scholarly journals Experimental Study on the Correlation between Crack Width and Crack Depth of RC Beams

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 5950
Author(s):  
Yue Li ◽  
Juhui Zhang ◽  
Zhongguo Guan ◽  
Youliang Chen
Keyword(s):  
Crack Width ◽  
Visual Inspection ◽  
Concrete Strength ◽  
Crack Depth ◽  
Reinforcement Ratio ◽  
Rc Beams ◽  
Test Results ◽  
Loading Test ◽  
Static Loading Test ◽  
Good Agreement

The depth of cracks propagating inside reinforcement concrete (RC) components is barely able to be detected by visual inspection. Without any help from facilities, crack width can provide us with a proper way to explore the depth of cracks developing. Therefore, this paper tried to explore the correlation between crack width on the surface and crack depth. A static loading test was conducted on eight RC beams, considering the variation of concrete strength, cover, and reinforcement ratio. The test results indicate that concrete strength has a certain impact on cracking load and the propagation of cracks is mainly related to reinforcement ratio. The linear changes in load and crack width can be found. Originally, crack depth markedly increased with loading, but when restricted by compression zone of concrete and the height of beams, crack depth stopped extending finally. The correlation between crack width and crack depth was analyzed by studying work phases of a cross-section and experimental data. The fitting function achieved in this paper was determined to be a good agreement between the theoretical and the experimental relationship.

Strengthening of reinforced concrete corbels with GFRP overlays

2011 ◽  
Vol 18 (1-2) ◽  
pp. 69-77 ◽  
Author(s):  
Sevket Ozden ◽  
Hilal Meydanli Atalay
Keyword(s):  
Reinforced Concrete ◽  
Reinforcement Ratio ◽  
Fiber Reinforced Polymer ◽  
Peak Performance ◽  
Test Results ◽  
Loading Test ◽  
Load Bearing Capacity ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced ◽  
Normal Strength

AbstractThe strength and post-peak performance of reinforced concrete corbels, strengthened with epoxy bonded glass fiber reinforced polymer (GFRP) overlays, were experimentally investigated. The test variables were the corbel shear span to depth ratio, corbel main reinforcement ratio, and the number and orientation of the GFRP fibers. In total, 24 normal strength concrete, one-third scale, corbel specimens, without hoop reinforcement, were tested to failure under quasi-static gravity loading. Test results revealed that GFRP overlays can easily be used for the enhancement of corbel load bearing capacity, depending on the fiber orientation. The main reinforcement ratio and the number of GFRP plies were found to be the two main variables affecting the level of strength gain in the corbel specimens.

An Experiment on Bond-Anchoring Property of Prestressing Spiral Groove Tendon

2011 ◽  
Vol 105-107 ◽  
pp. 1685-1688
Author(s):  
Meng Chen ◽  
Pin Wu Guan
Keyword(s):  
Yield Strength ◽  
Failure Modes ◽  
Concrete Strength ◽  
Concrete Cover ◽  
Tensile Yield Strength ◽  
Test Results ◽  
Statistical Regression ◽  
Spiral Groove ◽  
Anchoring Strength ◽  
Good Agreement

Prestressing spiral groove tendon is a new sort prestressing tendon, its characteristic value of tensile yield strength fyk=1000MPa. Firstly, the yield strength, ultimate tensile strength, elastic modulus and elongation are all tested. According to 68 pullout tests, the bond-anchoring curves and failure modes have been studied, and the effects of concrete strength, diameter, anchoring length, thickness of concrete cover and stirrup ratio have been all analyzed. Finally, the equation for ultimate bond-anchoring strength has been suggested by statistical regression, and the test results are in good agreement with values of the suggested equation.

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.

Deflection Prediction of FRP-Strengthened Reinforced Concrete Beams

2011 ◽  
Vol 243-249 ◽  
pp. 621-624
Author(s):  
Gui Bing Li ◽  
Yu Gang Guo
Keyword(s):  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Fiber Reinforced Polymer ◽  
Rc Beams ◽  
Test Results ◽  
Structural Members ◽  
Modified Model ◽  
Reinforced Polymer ◽  
Service Load ◽  
Good Agreement

Bonding fiber reinforced polymer (FRP) laminates to the tension face of RC members has been proven to be an effective method to improve the flexural strength. However, structural members are not only needed to have adequate strength, but also to have adequate performance of deformation at service load levels. To evaluate the deflection of externally FRP-strengthened RC beams, a total of 18 RC beams, including 16 beams strengthened with CFRP laminate under different preload levels and 2 control beams, were tested. Based on the assumption that the section of the beam behaves a tri-linear moment-curvature response characterized by pre-crack stage, post-crack stage and failure stage and the test results, this paper presents a modified model to evaluate the deflection of CFRP-strengthened RC beams. The present modified model was verified by the similar test results, and shows a good agreement with the test results.

scholarly journals Investigation of the Mechanical Behavior of Partially Precast Partially Encased Assembled Composite Beams

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Liufeng Zhang ◽  
Yinghua Yang
Keyword(s):  
Mechanical Properties ◽  
Composite Beam ◽  
Low Cost ◽  
Concrete Strength ◽  
Composite Beams ◽  
Test Results ◽  
Structural Form ◽  
Heavy Load ◽  
Grade Steel ◽  
Good Agreement

In view of the characteristics of a high floor and the heavy load of logistics buildings, a partially prefabricated partially encased assembled composite beam (PPEC) is proposed in order to achieve the low cost construction of such buildings. In this research, the mechanical properties of PPEC beams were studied experimentally. The effects of the concrete strength grade, steel content, shear span ratio, and fabrication methods on the mechanical properties of the PPEC beams were analyzed. The results showed that the proposed structural form of the PPEC beams was generally feasible. Based on the test results, a practical shear formula for PPEC beams was proposed, and the calculated results were in good agreement with the test results.

scholarly journals Flexural Rigidity in Concrete Beam by using the Crimped Steel Fibers with Rapid Hardening Admixtures

2019 ◽  
Vol 8 (6) ◽  
pp. 1677-1681
Keyword(s):  
Fly Ash ◽  
Flexural Rigidity ◽  
Concrete Strength ◽  
Crack Depth ◽  
Steel Fibers ◽  
Fine Aggregate ◽  
Test Results ◽  
Rapid Hardening ◽  
Depth Measurement ◽  
Crack Depth Measurement

With the increase in the fast track construction industries, the emerging techniques are used for improvement in the concrete strength and its properties. This paper focused on the test results for various mixes of concrete made by replacing OPC cement content with slag and fly ash in varying proportions the use of rapid hardening admixture along with the presence of crimped steel fibers. The flexural strength, crack depth measurement by using the ultrasonic pulse velocity and Elastic modulus of concrete were conducted with different proportions of fly ash (0-15%) and slag (0-25%) being replaced in cement and 0-50% of the fine aggregate is replaced with stone dust. The experimental test results show the volume reduction in flexural members, crack depth measurement by UPV and modulus of elasticity of concrete by scant modulus method was used for various mixes.

scholarly journals Seismic Behavior Investigations of the Haunched Joint with Ribbed Anchor Webs in CFDST Structures

2021 ◽  
Author(s):  
yufen zhang ◽  
Hongfan Bu ◽  
Shengxi Cao
Keyword(s):  
Energy Dissipation ◽  
Stress Responses ◽  
Failure Modes ◽  
Concrete Strength ◽  
Material Strength ◽  
Fe Modeling ◽  
Test Results ◽  
Loading Test ◽  
Column Joint ◽  
Seismic Behaviors

Abstract The haunched joint with ribbed anchor webs in the concrete-filled double steel tubular (CFDST) structure was proposed in this study. The CFDST column and the steel beam were connected by vertical ribbed webs, which were anchored inside the column and connected to the beam web by the bolted connection, and haunches were welded to shift plastic hinges from the joint core to beam ends. The cyclic loading test was conducted on three beam-to-column joint specimens. Seismic behaviors including failure modes, strain and stress responses, hysteretic curves, ductility, and energy dissipation capacity were respectively analyzed. Besides, a finite element (FE) modeling was completed by ABAQUS in consideration of geometric and material nonlinearity. The validity of FE modeling was checked by comparisons between FE results and test results, and research results confirmed that the beam-to-column rotation and the shear deformation in the joint core were small owing to the restriction from the configuration of haunches. Then parametric investigations on connection constructional details, geometric dimensions, material strength, and axial compression ratios, were made to study seismic behaviors of the haunched joint with ribbed anchor webs. It showed that the selected parameters except concrete strength had certain influences on bearing capacity, ductility, and energy dissipation, and corresponding practicable design suggestions were proposed for the application of haunched joints with ribbed anchor webs in CFDST structures.

scholarly journals The Mechanical Properties of Centrifuged Concrete in Reinforced Concrete Structures

2020 ◽  
Vol 10 (10) ◽  
pp. 3570
Author(s):  
Romualdas Kliukas ◽  
Ona Lukoševičienė ◽  
Arūnas Jaras ◽  
Bronius Jonaitis
Keyword(s):  
Mechanical Properties ◽  
Reinforced Concrete ◽  
Concrete Strength ◽  
Concrete Structures ◽  
High Strength ◽  
Reinforcement Ratio ◽  
Transverse Reinforcement ◽  
Reinforced Concrete Structures ◽  
Test Results ◽  
Moduli Of Elasticity

This article explores the influence of transverse reinforcement (spiral) and high-strength longitudinal reinforcements on the physical-mechanical properties of centrifuged annular cross-section elements of concrete. The test results of almost 200 reinforced, and over 100 control elements are summarizing in this article. The longitudinal reinforcement ratio of samples produced in the laboratory and factory varied from 1.0% to 6.0%; the transverse reinforcement ratio varied from 0.25% to 1.25%; the pitch of spirals varied from 100 mm to 40 mm and the concrete strength varied from 25 MPa to 60 MPa. Experimental relationships of coefficients for concrete strength, moduli of elasticity and limits of the longitudinal strain of centrifuged concrete in reinforced concrete structures in short-term concentrically compression were proposed.

scholarly journals Debonding Failure Analysis of Reinforced Concrete Beams Strengthened with CFRP Plates

2021 ◽  
Author(s):  
Rendy Thamrin ◽  
Zaidir Zaidir ◽  
Silvy Desharma
Keyword(s):  
Reinforced Concrete ◽  
Modulus Of Elasticity ◽  
Reinforcement Ratio ◽  
Reinforced Concrete Beams ◽  
Fiber Reinforced Polymers ◽  
Analytical Prediction ◽  
Rc Beams ◽  
Test Results ◽  
Fiber Element ◽  
Element Method

In this study, experimental work was carried out on reinforced concrete (RC) beams strengthened with carbon fiber reinforced polymers (CFRP) plates. This study aims to examine the effect of the reinforcement ratio on the flexural behavior of these beams and propose a new model for predicting the debonding moment. Six RC beams consisting of three control beams and three beams strengthened with CFRP plates were tested. The beams were simply supported and loaded with four-point bending. The test variable was the tensile reinforcement ratio (1%, 1.5%, and 2.5%). Analytical prediction using the fiber element method was also carried out to obtain the complete theoretical response of the beam due to flexural loads. The test results show that the reinforcement ratio affected the bending performance of RC beams with CFRP plates. Following this, the experimental data from 60 beam test results from published literature and this study were analyzed. From these data, it was found that the ratio of tensile reinforcement, the ratio of modulus of elasticity of concrete, the modulus of elasticity of the plate, and plate thickness all affect the value of debonding moment. A parametric study using fiber element and two-dimensional finite element method was also carried out to confirm the effect of these parameters on debonding failure. These parameters were then used to develop an equation to predict the debonding moment of RC beams strengthened with CFRP plates using simple statistical analysis. This analysis resulted in a simple model for predicting the debonding moment. Then the model is entered into a computer program, and the complete response of the cross-section due to debonding failure can be obtained.

A Field Experimental Study of Composite Foundation with Rammed Soil-Cement Pile in Collapsible Loess Area

2014 ◽  
Vol 1030-1032 ◽  
pp. 969-973 ◽  
Author(s):  
Hai Jian Sun ◽  
Shi You Zhang
Keyword(s):  
Composite Foundation ◽  
Engineering Properties ◽  
Test Results ◽  
Loading Test ◽  
Foundation Soil ◽  
Loess Area ◽  
Soil Cement ◽  
Static Loading Test ◽  
Natural Foundation ◽  
Field Static

Natural foundation in loess areas is collapsible; however, composite foundation with rammed soil-cement pile can be used to meet the load requirements of the building. Immersion-compression test and field static loading test were carried out to measure the treatment effect. The test results showed that: the collapsible of loess foundation can be eliminated by treatment with rammed soil-cement pile when the loading pressure is between 200 to 500 kPa. Engineering properties of the foundation soil between piles are improved. The parameters improve more obvious with the pile spacing getting smaller. The bearing capacity of composite foundation increased to 291 kPa, compared with natural loess foundation. The research results can be applied to design and construction of compacted soil cement pile composite foundation in loess area.

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