scholarly journals Influence of Patching on the Shear Failure of Reinforced Concrete Beam without Stirrup

2021 ◽  
Vol 6 (7) ◽  
pp. 97
Author(s):  
Stefanus Adi Kristiawan ◽  
Halwan Alfisa Saifullah ◽  
Agus Supriyadi
Keyword(s):  
Reinforced Concrete ◽  
Shear Failure ◽  
Numerical Study ◽  
Unsaturated Polyester ◽  
Reinforced Concrete Beam ◽  
Concrete Cover ◽  
Shear Capacity ◽  
Rc Beam ◽  
Shear Span ◽  
Shear Cracking

Deteriorated concrete cover, e.g., spalling or delamination, especially when it occurs at the web of a reinforced concrete (RC) beam within the shear span, can reduce the shear capacity of the beam. Patching of this deteriorated area may be the best option to recover the shear capacity of the beam affected. For this purpose, unsaturated polyester resin mortar (UPR mortar) has been formulated. This research aims to investigate the efficacy of UPR mortar in limiting the shear cracking and so restoring the shear capacity of the deteriorated RC beam. The investigation is carried out by an experimental and numerical study. Two types of beams with a size of 150 × 250 × 1000 mm were prepared. The first type of beams was assigned as a normal beam. The other was a beam with a cut off in the non-stirrup shear span, which was eventually patched with UPR mortar. Two reinforcement ratios were assigned for each type of beams. The results show that UPR mortar is effective to hamper the propagation of diagonal cracks leading to increase the shear failure load by 15–20% compared to the reference (normal) beam. The increase of shear strength with the use of UPR mortar is consistently confirmed at various reinforcement ratios.

Shear Failure of Patched Reinforced Concrete Beam without Web Reinforcements

2017 ◽  
Vol 737 ◽  
pp. 441-447 ◽  
Author(s):  
Stefanus Kristiawan ◽  
Agus Supriyadi ◽  
Senot Sangadji ◽  
Hapsara Brian Wicaksono
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Shear Failure ◽  
Unsaturated Polyester ◽  
Reinforced Concrete Beam ◽  
Concrete Cover ◽  
Patch Repair ◽  
Rc Beam ◽  
Diagonal Crack ◽  
The Web

Degradation of reinforced concrete (RC) element could lead to a reduction of its strength and serviceability. The degradation may be identified in the form of spalling of concrete cover. For the case of RC beam, spalling of concrete cover could occur at the web of the shear span due to corrosion of the web reinfocements. The shear strength of the damaged-RC beam possibly will become less conservative compared to the corresponding flexural strength with a risk of brittle failure. Patch repair could be a choice to recover the size and strength of the damaged-RC beam. This research investigates the shear failure of patched RC beam without web reinforcements with a particular interest to compare the shear failure behaviour of patched RC beam and normal RC beam. The patch repair material used in this research was unsaturated polyester resin (UPR) mortar. The results indicate that the initial diagonal cracks leading to shear failure of patched RC beam occur at a lower level of loading. However, the patched RC beam could carry a greater load before the diagonal crack propagates in length and width causing the beam to fail in shear.

scholarly journals THE EFFECTS OF INCLINED SHEAR REINFORCEMENT IN REINFORCED CONCRETE BEAM

2018 ◽  
Vol 30 (1) ◽  
Author(s):  
Nor Fazlin Zamri ◽  
Roslli Noor Mohamed ◽  
NurHafizah A. Khalid ◽  
Kang Yong Chiat
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Shear Failure ◽  
Reinforced Concrete Beam ◽  
Rc Beam ◽  
Rc Beams ◽  
Shear Reinforcement ◽  
Strain Behaviour ◽  
Different Types ◽  
Loading System

This paper presents the findings of an experimental data on the effects of inclined shearreinforcement in reinforced concrete (RC) beam. Two types of shear reinforcement of RC beamwere investigated, conventional stirrups (vertical links) and inclined shear reinforcement (45degrees of inclined shear reinforcement). The RC beam with conventional stirrups wasdesignated as a control specimen. The RC beams with different types of shear reinforcementwere tested for shear under four-point loading system. Comparisons were made between bothtypes of RC beam on load-deflection, load-steel strain, load-concrete strain behaviour and modeof failure. The theoretical and experimental were calculated by using conventional formulation inaccordance to EC 2 in order to verify the experimental results. From the results, it was observedthat the RC beam with 45 degree inclined shear reinforcement improved structural performancein shear by approximately 20% and thus prolong the shear failure behaviour as compared to theRC beam with vertical links.

scholarly journals Numerical analysis of reinforced concrete beam subject to pitting corrosion

2022 ◽  
Vol 22 (1) ◽  
pp. 201-222
Author(s):  
Éverton Souza Ramos ◽  
Rogério Carrazedo
Keyword(s):  
Reinforced Concrete ◽  
Service Life ◽  
Pitting Corrosion ◽  
Numerical Study ◽  
Reinforced Concrete Beam ◽  
Concrete Cover ◽  
Structural Element ◽  
Deterministic Models ◽  
Faraday’S Law ◽  
Parametric Analyses

Abstract This paper presents a numerical study about the effects of chloride-induced corrosion on the service life of structures. A two-dimensional geometrically nonlinear mechanical model based on Finite Element Method (FEM) was developed for reinforced concrete structures. The corrosion initiation stage was evaluated by Fick's diffusion laws. The corrosion propagation was carried out by deterministic models based on Faraday's law. Pitting corrosion was simulated in the reinforcements by pit elements, distributed longitudinally on the steel rebars, which degrade the physical properties over time. The service life was determined by the crack width.Two parametric analyses were performed. In the first analysis, five models were created with a variablecover thickness and water/cement ratio (w/c). In the second analysis, the reduction in yield stress due to corrosion was considered.The results showed that the concrete cover thicknessand the w/c ratio significantly influence the service life. The reduction of the cover thickness from 30 mm to 25 mm resulted in 21.26% reduction in service life, whilethe increase in the w/c ratio from 0.50 to 0.55 caused 32.98% reduction in service life of the structural element analyzed.

scholarly journals Damage Evaluation in Shear-Critical Reinforced Concrete Beam using Piezoelectric Transducers as Smart Aggregates

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Constantin E. Chalioris ◽  
Nikos A. Papadopoulos ◽  
Georgia M. Angeli ◽  
Chris G. Karayannis ◽  
Asterios A. Liolios ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Shear Failure ◽  
Reinforced Concrete Beam ◽  
Piezoelectric Transducers ◽  
Reinforced Concrete Beams ◽  
Structural Safety ◽  
Shear Span ◽  
Externally Bonded ◽  
Diagonal Crack

AbstractDamage detection at early cracking stages in shear-critical reinforced concrete beams, before further deterioration and their inevitable brittle shear failure is crucial for structural safety and integrity. The effectiveness of a structural health monitoring technique using the admittance measurements of piezoelectric transducers mounted on a reinforced concrete beam without shear reinforcement is experimentally investigated. Embedded “smart aggregate” transducers and externally bonded piezoelectric patches have been placed in arrays at both shear spans of the beam. Beam were tested till total shear failure and monitored at three different states; healthy, flexural cracking and diagonal cracking. Test results showed that transducers close to the critical diagonal crack provided sound and graduated discrepancies between the admittance responses at the healthy state and thedamage levels.Damage assessment using statistical indices calculated from the measurements of all transducers was also attempted. Rational changes of the index values were obtained with respect to the increase of the damage. Admittance responses and index values of the transducers located on the shear span where the critical diagonal crack formed provided cogent evidence of damage. On the contrary, negligible indication of damage was yielded by the responses of the transducers located on the other shear span, where no diagonal cracking occurred.

Experimental Study on Shear of Reinforced Concrete Beams with High Strength Rebars as Stirrups under Different Shear Span Ratios

2014 ◽  
Vol 578-579 ◽  
pp. 164-167 ◽  
Author(s):  
Peng Li ◽  
Xian Tang Zhang ◽  
Ming Ping Wang
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Concrete Beams ◽  
High Strength ◽  
Reinforced Concrete Beam ◽  
Shear Behavior ◽  
Shear Capacity ◽  
Reinforced Concrete Beams ◽  
Test Results ◽  
Shear Span

To investigate the influence of shear span ratio for the shear behavior of reinforced concrete beam with HRBF500 high strength rebars as stirrups, an experiment was carried out, which included 8 simply supported beams with HRBF500 rebars as stirrups. Under concentrated loads, the crack, deflection, strain of rebars, bearing capacity and failure mode are observed under different shear span ratios. Some comparisons are made between test results and calculated outcome. It shows that the shear span ratio has very important influent on the shear behavior of reinforced concrete beam with HRBF500 high strength bars as stirrups. Formula in code for design of concrete structures can be used to calculate its shear capacity with enough safety.

Behaviour of reinforced concrete beam strengthened in shear with geosynthetic

2020 ◽  
Vol 23 (9) ◽  
pp. 1851-1864 ◽  
Author(s):  
Subhrasmita Majumder ◽  
Showmen Saha
Keyword(s):  
Reinforced Concrete ◽  
Shear Failure ◽  
Concrete Beams ◽  
Single Point ◽  
Reinforced Concrete Beam ◽  
Primary Objective ◽  
Absorption Capacity ◽  
Shear Capacity ◽  
Reinforced Concrete Beams ◽  
Experimental Findings

The primary objective of this article is to focus on the experimental investigation of shear-deficient and geosynthetic-strengthened reinforced concrete beams. In this study, two varieties of geosynthetic, namely geogrid and geotextile, are used. The performances of shear-deficient reinforced concrete beams strengthened with geosynthetics under the single-point static monotonic loading are studied. It is observed that shear failure occurs in shear-deficient beam, but after strengthening the brittle shear failure changes to ductile flexure failure. A significant increment in flexural strength, ductility, energy absorption capacity and inelastic performance is observed in strengthened beams. The performance of geogrid is better in all respects when compared to the geotextile. The test results reveal that the use of geosynthetic not only increases the shear capacity but also remarkably improves the ductile behaviour of RC beams. In addition, conventional analytical methods are applied for the evaluation of the ultimate load, and the results are compared with the experimental findings, which show a good agreement between the analytical and experimental results.

scholarly journals Toward Structural Health Monitoring of Civil Structures Based on Self-Sensing Concrete Nanocomposites: A Validation in a Reinforced-Concrete Beam

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Diego L. Castañeda-Saldarriaga ◽  
Joham Alvarez-Montoya ◽  
Vladimir Martínez-Tejada ◽  
Julián Sierra-Pérez
Keyword(s):  
Reinforced Concrete ◽  
Damage Detection ◽  
Direct Current ◽  
Health Monitoring ◽  
Electrical Resistance ◽  
Concrete Beam ◽  
Reinforced Concrete Beam ◽  
Structural Member ◽  
Rc Beam ◽  
Electric Resistance

AbstractSelf-sensing concrete materials, also known as smart concretes, are emerging as a promising technological development for the construction industry, where novel materials with the capability of providing information about the structural integrity while operating as a structural material are required. Despite progress in the field, there are issues related to the integration of these composites in full-scale structural members that need to be addressed before broad practical implementations. This article reports the manufacturing and multipurpose experimental characterization of a cement-based matrix (CBM) composite with carbon nanotube (CNT) inclusions and its integration inside a representative structural member. Methodologies based on current–voltage (I–V) curves, direct current (DC), and biphasic direct current (BDC) were used to study and characterize the electric resistance of the CNT/CBM composite. Their self-sensing behavior was studied using a compression test, while electric resistance measures were taken. To evaluate the damage detection capability, a CNT/CBM parallelepiped was embedded into a reinforced-concrete beam (RC beam) and tested under three-point bending. Principal finding includes the validation of the material’s piezoresistivity behavior and its suitability to be used as strain sensor. Also, test results showed that manufactured composites exhibit an Ohmic response. The embedded CNT/CBM material exhibited a dominant linear proportionality between electrical resistance values, load magnitude, and strain changes into the RC beam. Finally, a change in the global stiffness (associated with a damage occurrence on the beam) was successfully self-sensed using the manufactured sensor by means of the variation in the electrical resistance. These results demonstrate the potential of CNT/CBM composites to be used in real-world structural health monitoring (SHM) applications for damage detection by identifying changes in stiffness of the monitored structural member.

scholarly journals Experimental Study on the Shear Performance of Steel-Truss-Reinforced Concrete Beam-Column Joints

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Dafu Cao ◽  
Jiaqi Liu ◽  
Wenjie Ge ◽  
Rui Qian
Keyword(s):  
Bearing Capacity ◽  
Axial Compression ◽  
Compression Ratio ◽  
Shear Failure ◽  
Reinforced Concrete Beam ◽  
Ultimate Bearing Capacity ◽  
Shear Capacity ◽  
Core Area ◽  
Axial Compression Ratio ◽  
Steel Truss

In order to study the influence of the axial compression ratio and steel ratio on the shear-carrying capacity of steel-truss-reinforced beam-column joints, five shear failure interior joint specimens were designed. The effect of different coaxial pressure ratios (0.1, 0.2, and 0.3) and steel contents on the strain, ultimate bearing capacity, seismic performance, and failure pattern of cross-inclined ventral and chord bars in the joint core area was investigated. The experimental results show that the load-displacement hysteretic curves of all test specimens exhibit a bond-slip phenomenon. With the increase of the axial compression ratio, the ultimate bearing capacity of the joint core increases by 3.4% and 5.9%, respectively. While the ductility decreases by 10.3% and 13.1%, and the energy consumption capacity decreases by 3.2% and 5.8%, respectively. The shear capacity and ductility of the member with cross diagonal ventral steel angle in the joint core are increased by 12.9% and 13.4%, respectively. The shear capacity and ductility of the joint can be significantly improved by increasing the amount of steel in the core area. The expression of shear capacity suitable for this type of joint is obtained by fitting analysis, which can be used as a reference for engineering design.

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