scholarly journals Experimental Investigations of Reinforced Concrete Beams with Innovative Truss-Shaped Reinforcement System

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1652
Author(s):  
Adam Stolarski ◽  
Jacek Zychowicz
Keyword(s):  
Reinforced Concrete ◽  
Carrying Capacity ◽  
Concrete Beams ◽  
Reinforcement Ratio ◽  
Reinforced Concrete Beams ◽  
Load Carrying Capacity ◽  
Longitudinal Reinforcement ◽  
Test Results ◽  
Reinforcement System ◽  
Load Carrying

The purpose of the work is an experimental analysis of the behavior of reinforced concrete beams with a new, patented system of truss-shaped reinforcement. Experimental tests of reinforced concrete beams with conventional reinforcement and with truss-shaped, mass equivalent reinforcement, with two different values of longitudinal reinforcement ratio, were carried out. The testing results of the load-carrying capacity and displacements of beams are presented. The cracking and failure mechanism of beams with a new truss-shaped reinforcement system was also analyzed. The test results for conventionally reinforced beams and with truss-shaped reinforcement were compared. The test results show that the use of the truss reinforcement has an influence on increasing the load-carrying capacity of beams. The amount of this increase depends on the total longitudinal reinforcement ratio and reaches as much as 95% for beams with a low reinforcement ratio and 12% for beams with a higher reinforcement ratio. Based on the investigation of the cracking mechanism, it can be concluded that the failure of the beams with transverse truss-shaped reinforcement occurs with a greater number of smaller cracks, which are more evenly distributed along the length of the cracking zone, and have a shorter range over the cross-section depth, which results in their smaller opening widths. The comparative analysis shows the effectiveness of the proposed reinforcement system, justifying the high potential possibilities of its use for the reinforcement of concrete structural elements.

scholarly journals The analysis of load carrying capacity and cracking of slightly reinforced concrete members in bending

2008 ◽  
Vol 2 (1) ◽  
pp. 065-078
Author(s):  
Marta Słowik
Keyword(s):  
Reinforced Concrete ◽  
Carrying Capacity ◽  
Concrete Beams ◽  
Plain Concrete ◽  
Reinforcement Ratio ◽  
Reinforced Concrete Beams ◽  
Load Carrying Capacity ◽  
Test Results ◽  
Concrete Members ◽  
Load Carrying

Slightly reinforced concrete members are the members made by concrete with reinforcement less than minimum given in codes for reinforced concrete ones. Plain concrete and slightly reinforced concrete members in bending are treated in the same way during the dimensioning and the influence of longitudinal reinforcement on the load carrying capacity is not taken into account. The mechanism of work and crack formation in slightly reinforced concrete members is not completely recognized. The author’s own research program was made. The experiment was aimed at the determination of cracking moment and load carrying capacity of slightly reinforced concrete beams with different reinforcement ratio. Also plain concrete beams and the typical reinforced concrete beam were tested. The analysis of the obtained values of maximum bending moment and crack’s widths was made according to the reinforcement ratio. The analysis of test results shows how the presence of longitudinal steel bars in concrete members, even when reinforcement ratio is low, changes cracking process and influences the value of cracking moment in flexural members. On the basis of test results, the method how to calculate the load carrying capacity of slightly reinforced concrete elements in bending has been proposed.

scholarly journals Strengthening of Reinforced Concrete Beams Subjected to Concentrated Loads

2022 ◽  
Author(s):  
Paolo Foraboschi
Keyword(s):  
Reinforced Concrete ◽  
Carrying Capacity ◽  
Concrete Beams ◽  
Shear Capacity ◽  
Reinforced Concrete Beams ◽  
Load Carrying Capacity ◽  
Reinforced Concrete Structure ◽  
Concentrated Loads ◽  
Concentrated Load ◽  
Load Carrying

Renovation, restoration, remodeling, refurbishment, and retrofitting of build-ings often imply modifying the behavior of the structural system. Modification sometimes includes applying forces (i.e., concentrated loads) to beams that before were subjected to distributed loads only. For a reinforced concrete structure, the new condition causes a beam to bear a concentrated load with the crack pattern that was produced by the distributed loads that acted in the past. If the concentrated load is applied at or near the beam’s midspan, the new shear demand reaches the maximum around the midspan. But around the midspan, the cracks are vertical or quasi-vertical, and no inclined bar is present. So, the actual shear capacity around the midspan not only is low, but also can be substantially lower than the new demand. In order to bring the beam capacity up to the demand, fiber-reinforced-polymer composites can be used. This paper presents a design method to increase the concentrated load-carrying capacity of reinforced concrete beams whose load distribution has to be changed from distributed to concentrated, and an analytical model to pre-dict the concentrated load-carrying capacity of a beam in the strengthened state.

Guidelines for flexural design of FRP reinforced concrete beams

2020 ◽  
pp. 002199832097373
Author(s):  
Fares Jnaid
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Carrying Capacity ◽  
Concrete Beams ◽  
Large Diameter ◽  
Reinforced Concrete Beams ◽  
Load Carrying Capacity ◽  
Concrete Compressive Strength ◽  
Load Carrying ◽  
Multiple Variables

This paper investigates the effects of different parameters on the live load carrying capacity of concrete beams reinforced with FRP bars. The author performed a parametric study utilizing an innovative numerical approach to inspect the effects of multiple variables such as reinforcement ratio, concrete compressive strength, span to depth ratio, FRP type, and bar diameter on load carrying capacity of FRP reinforced concrete beams. This study concluded that unless the span to height ratio is smaller than 8, tension-controlled sections are impractical as they do not meet code requirements for serviceability. In addition, it is recommended to use higher reinforcement ratios when using larger span to depth ratios and/or when using CFRP reinforcing bars. Moreover, larger number of bars with small diameter is more practical than fewer large diameter bars. Furthermore, this research suggests that increasing the concrete compressive strength is associated with a significant increase in the ultimate flexural capacity of FRP reinforced beams.

scholarly journals The influence of simultaneous action of the aggressive environment and loading on strength of RC beams

2018 ◽  
Vol 183 ◽  
pp. 02002 ◽  
Author(s):  
Jacek Selejdak ◽  
Roman Khmil ◽  
Zinoviy Blikharskyy
Keyword(s):  
Reinforced Concrete ◽  
Carrying Capacity ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Simultaneous Action ◽  
Load Carrying Capacity ◽  
Aggressive Environment ◽  
Load Carrying ◽  
Acid Environment ◽  
Simultaneous Influence

The article is devoted to an experimental research of the strength of reinforced concrete beams, and its dependence on a simultaneous influence of a corrosion environment and a loading factor. The tests have been carried out upon reinforced concrete specimens of 2100×200×100 mm size, with a regular reinforcement. The beams are of a span equaling to 1,9m with different reinforcing ratio of beams. The acid environment, namely 10 % H2SO4, was taken as a model of an aggressive environment. Reinforced concrete beams have been tested with and without the co-action of the aggressive environment and loading factor. Beams, which underwent a simultaneous action of the corrosive environment and loading, were loaded to a level 0.7 of its load-carrying capacity. The load-carrying capacity in aggressive environment in all the beams of all the series was achieved in 46-60 days. The influence of the simultaneous action of the aggressive environment and loading on the strength of reinforced-concrete beams has been described in the following work. It is necessary to note that the design code of Ukraine does not allow determining load carrying capacity of the beams affected by corrosion with simultaneous influence of loading with adequate accuracy. The analysis of experimental data has been done and the main directions of the design code’s correction have been formulated.

scholarly journals BEHAVIOUR OF REINFORCED CONCRETE BEAMS WITHOUT STIRRUPS SUBJECTED TO STEEL REINFORCEMENT CORROSION

2016 ◽  
Vol 22 (2) ◽  
pp. 146-153 ◽  
Author(s):  
Rizwan AZAM ◽  
Ahmed K. EL-SAYED ◽  
Khaled SOUDKI
Keyword(s):  
Reinforced Concrete ◽  
Reinforced Concrete Beams ◽  
Load Carrying Capacity ◽  
Longitudinal Reinforcement ◽  
Rc Beams ◽  
Test Results ◽  
Structural Behaviour ◽  
Three Point Bending ◽  
Load Carrying ◽  
Crack Widths

The effect of corrosion on the structural behaviour of reinforced concrete (RC) beams without stirrups was experimentally investigated. A total of seven medium-scale RC beams without stirrups were constructed. The beams measured 150 mm wide, 250 mm deep and 1700 mm long. The test variables included: three different longitudinal reinforcement ratios (0.91%, 1.21%, and 1.82%) and two different corrosion levels (3% and 10%). Four beams were subjected to artificial corrosion whereas three beams acted as control un-corroded. Following the corrosion phase, all beams were tested to failure in three point bending. Corrosion crack widths and cracking patterns were recorded at different stages of corrosion. The effect of different longitudinal reinforcement ratios on the rate of corrosion was observed. Test results revealed that the beams with higher reinforcement ratios experienced slower corrosion rate compared to beams with lower reinforcement ratios. All control beams failed in shear whereas corroded beams failed in bond. There was a significant reduction in the load carrying capacity of the corroded beams without stirrups compared to the control beams.

Responses of Plain and Steel Fiber-Reinforced Concrete Beams to Temperature and Mechanical Loads: Experimental Study

2000 ◽  
Vol 1740 (1) ◽  
pp. 25-32 ◽  
Author(s):  
Ali Alavizadeh-Farhang ◽  
Johan Silfwerbrand
Keyword(s):  
Reinforced Concrete ◽  
Carrying Capacity ◽  
Steel Fiber ◽  
Concrete Beams ◽  
Fiber Reinforced Concrete ◽  
Reinforced Concrete Beams ◽  
Load Carrying Capacity ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Load Carrying

To study the structural responses of plain and steel fiber-reinforced concrete pavements under combined mechanical and thermal loads, two test series have been conducted with plain and steel fiber-reinforced concrete beams. The magnitude and duration of the differences in the induced stresses caused by traffic load and a positive nonlinear temperature gradient (the top surface was warmer than the bottom surface during the day) may lead to some relaxation of thermal stresses and subsequently increase the load-carrying capacity. Considering the loss of support contact in the interior part of the concrete pavement, the experimental study of combined loading with restrained concrete beams may provide some insight and an indication of whether the superposition of stresses is a proper approach. The beams were subjected to solely thermal, solely mechanical, and combined thermal and mechanical loads while the rotation of the beam at supports was prevented. The results of tests conducted with both plain and steel fiber-reinforced beams showed that the superposition of stresses under combined loading before cracking gave a satisfactory estimation of the load-carrying capacities. The results also showed that the effect of relaxation of stresses due to short-term thermal loads was not noticeable in the load-carrying capacity achieved in tests with combined thermal and mechanical loads. On the contrary, a tendency for reduction of the load-carrying capacity was observed at higher thermal gradients. In addition, the overall structural responses of steel fiber-reinforced concrete beams under mechanical load and a nonlinear temperature gradient combined were similar to the responses of plain concrete beams up to the cracking stage. However, the release of thermal stresses due to cracking and the considerable residual load-carrying capacity after cracking were the most important observations for steel fiber-reinforced concrete beams.

scholarly journals Flexural Behaviour Of Reinforced Concrete Beams Containing Expanded Glass As Lightweight Aggregates

2015 ◽  
Vol 23 (4) ◽  
pp. 1-7 ◽  
Author(s):  
Jamal Khatib ◽  
Adrian Jefimiuk ◽  
Sammy Khatib
Keyword(s):  
Reinforced Concrete ◽  
Carrying Capacity ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Fine Aggregate ◽  
Load Carrying Capacity ◽  
Flexural Behaviour ◽  
Structural Concrete ◽  
Load Carrying

Abstract The flexural properties of reinforced concrete beams containing expanded glass as a partial fine aggregate (sand) replacement are investigated. Four concrete mixes were employed to conduct this study. The fine aggregate was replaced with 0%, 25%, 50% and 100% (by volume) expanded glass. The results suggest that the incorporation of 50% expanded glass increased the workability of the concrete. The compressive strength was decreasing linearly with the increasing amount of expanded glass. The ductility of the concrete beam significantly improved with the incorporation of the expanded glass. However, the load-carrying capacity of the beam and load at which the first crack occurs was reduced. It was concluded that the inclusion of expanded glass in structural concrete applications is feasible.

Effect of Beam Depth and Longitudinal Reinforcement Ratio on Shear Strength of RC Beams

2010 ◽  
Vol 163-167 ◽  
pp. 1460-1465
Author(s):  
Lei Yu ◽  
Yi Che ◽  
Xin Feng Zheng ◽  
Jin Xin Gong ◽  
Yu Pu Song
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Concrete Beams ◽  
Reinforcement Ratio ◽  
Reinforced Concrete Beams ◽  
Shear Behaviour ◽  
Longitudinal Reinforcement ◽  
Test Results ◽  
Beam Depth ◽  
Insight Into

Seven beams were tested to investigate the effects of beam depth and longitudinal reinforcement ratio on the shear strength of reinforced concrete beams. To investigate the effects of beam depth on shear strength, beams of five different sizes were tested. Two beams were designed to investigate the shear behaviour of beams with small percentage of longitudinal reinforcement. In addition to an experimental investigation, a survey of data in the literature was performed to gain insight into the influence of beam depth and longitudinal reinforcement ratio. Based on test results and a data analysis, conclusions regarding the influence of beam depth and longitudinal reinforcement ratio on shear strength of reinforced concrete beams are presented herein.

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