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.

scholarly journals Experimental analysis of steel fiber reinforced concrete beams in shear

2022 ◽  
Vol 15 (3) ◽  
Author(s):  
Aaron Kadima Lukanu Lwa Nzambi ◽  
Dênio Ramam Carvalho de Oliveira ◽  
Marcus Vinicius dos Santos Monteiro ◽  
Luiz Felipe Albuquerque da Silva
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Steel Fiber ◽  
Concrete Beams ◽  
Reinforcement Ratio ◽  
Steel Fibers ◽  
Reinforced Concrete Beams ◽  
Experimental Program ◽  
Longitudinal Reinforcement ◽  
Fiber Addition

Abstract Some normative recommendations are conservative in relation to the shear strength of reinforced concrete beams, not directly considering the longitudinal reinforcement rate. An experimental program containing 8 beams of (100 x 250) mm2 and a length of 1,200 mm was carried out. The concrete compression strength was 20 MPa with and without 1.00% of steel fiber addition, without stirrups and varying the longitudinal reinforcement ratio. Comparisons between experimental failure loads and main design codes estimates were assessed. The results showed that the increase of the longitudinal reinforcement ratio from 0.87% to 2.14% in beams without steel fiber led to an improvement of 59% in shear strength caused by the dowel effect, while the corresponding improvement was of only 22% in fibered concrete beams. A maximum gain of 109% in shear strength was observed with the addition of 1% of steel fibers comparing beams with the same longitudinal reinforcement ratio (1.2%). A significant amount of shear strength was provided by the inclusion of the steel fibers and allowed controlling the propagation of cracks by the effect of stress transfer bridges, transforming the brittle shear mechanism into a ductile flexural one. From this, it is clear the shear benefit of the steel fiber addition when associated to the longitudinal reinforcement and optimal values for this relationship would improve results.

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.

Shear strength of disturbed regions with corroded stirrups in reinforced concrete beams

2010 ◽  
Vol 37 (8) ◽  
pp. 1045-1056 ◽  
Author(s):  
Christopher Suffern ◽  
Ahmed El-Sayed ◽  
Khaled Soudki
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Concrete Beams ◽  
Corrosion Damage ◽  
Reinforced Concrete Beams ◽  
Test Results ◽  
Accelerated Corrosion ◽  
Damage Level ◽  
Three Point Bending ◽  
Shear Span

This paper reports experimental data on the structural performance of disturbed regions in reinforced concrete beams with corrosion damage to the embedded steel stirrups. A total of 15 reinforced concrete beams were constructed and tested. The test beams were 350 mm deep, 125 mm wide, and 1850 mm long. The beams were tested in three-point bending under a simply supported span of 1500 mm. Nine beams had the embedded stirrups subjected to accelerated corrosion. The test variables were the corrosion damage level and the shear span-to-depth ratio. The test results indicated that the corroded beams exhibited reduced shear strength in comparison to the uncorroded control specimens. The shear strength reduction was up to 53%. Furthermore, the reduction in shear strength due to the corrosion was found to be greater at smaller shear span-to-depth ratios.

Does the shear strength of reinforced concrete beams and slabs depend upon the flexural reinforcement ratio or the reinforcement strain?

2013 ◽  
Vol 40 (11) ◽  
pp. 1068-1081 ◽  
Author(s):  
Mitra Noghreh Khaja ◽  
Edward G. Sherwood
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Concrete Beams ◽  
Reinforcement Ratio ◽  
Reinforced Concrete Beams ◽  
Shear Stresses ◽  
Shear Design ◽  
Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
General Method

Beam tests are conducted to investigate the effect of the reinforcement ratio, ρ, and the shear span to depth ratio, a/d, on the shear strength of reinforced concrete beams and slabs without stirrups. The a/d ratio is shown to have a very significant effect on shear strength at both low values of a/d (where failure is governed by strut-and-tie mechanisms) and large values of a/d (where failure is governed by breakdown in beam action). Increases in ρ associated with increases in a/d such that the strain, or M/ρVd ratio, is kept constant will result in constant failure shear stresses. Shear design methods that do not account for a/d (e.g., ACI Committee 440) cannot predict the observed experimental behaviour, whereas the general method of the CSA A23.3 code can. Using the ACI 440 equation for Vc may reduce the economic competitiveness of fibre-reinforced polymer reinforcement versus steel reinforcement.

scholarly journals Shear capacity of reinforced concrete beams strengthened with web side bonded CFRP sheets

2019 ◽  
Vol 258 ◽  
pp. 04010
Author(s):  
Rendy Thamrin ◽  
Zaidir ◽  
Sabril Haris
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Concrete Cover ◽  
Shear Capacity ◽  
Reinforcement Ratio ◽  
Reinforced Concrete Beams ◽  
Longitudinal Reinforcement ◽  
Flexural Mode ◽  
Cfrp Sheets ◽  
Reinforced Polymer

The shear capacity of reinforced concrete beams strengthened with web side bonded carbon fiber-reinforced polymer (CFRP) sheets was measured experimentally. Nine reinforced concrete beams without stirrups; three control beams and six beams strengthened with minimal application of web side bonded CFRP sheets, were tested. The test variables were ratio of longitudinal reinforcement (1%, 1.4%, and 2.4%) and angle of application of CFRP sheets (450 and 900). The test results show that reinforced concrete beams strengthened with web side bonded CFRP sheets have higher shear capacity compared to the control beams. Shear capacity of strengthened beams with 450 angle of application of CFRP sheets is similar to that of beams strengthened with 900 angles. Beams with 1% of longitudinal reinforcement ratio failed in flexural mode indicated by concrete crushing in compression zone while beams with higher longitudinal reinforcement ratio (1.4% and 2.4%) failed in brittle mode as indicated by delamination of the concrete cover.

scholarly journals Influence of tensile softening of concrete on crack development and failure in concrete and reinforced concrete beams

2019 ◽  
Vol 68 (1) ◽  
pp. 213-223 ◽  
Author(s):  
Marta Słowik
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Load Capacity ◽  
Plain Concrete ◽  
Reinforcement Ratio ◽  
Reinforced Concrete Beams ◽  
Test Results ◽  
Concrete Members ◽  
Cracking Process ◽  
Tensile Softening

In the paper, the own test results were presented. The experimental investigation was focused at determining the cracking and load capacity of beams made of concrete. The beams were characterized by different longitudinal reinforcement ratio from zero — plain concrete beams, through low ratio 0.12% — slightly reinforced concrete beams, middle ratio 0.9% — typical reinforced concrete beams, up to the ratios 1.3% and 1.8% — higher reinforced concrete beams. On the basis of the performed experiments and the results of numerical calculations, the process of crack’s formation and crack’s development in plain concrete, slightly reinforced concrete and reinforced concrete beams with different reinforcement ratio was described. When discussing cracking process in the beams, the contribution of strain softening of tensile concrete in the microcracked zone on the character of beams’ failure was analysed as well. Keywords: civil engineering, concrete and reinforced concrete members, cracking and load capacity.

scholarly journals Experimental Study on Shear Capacity of Reinforced Concrete Beams with Corroded Longitudinal Reinforcement

Materials ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 837 ◽  
Author(s):  
Sun-Jin Han ◽  
Hyo-Eun Joo ◽  
Seung-Ho Choi ◽  
Inwook Heo ◽  
Kang Kim ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Shear Capacity ◽  
Reinforced Concrete Beams ◽  
Longitudinal Reinforcement ◽  
Test Results ◽  
Reinforcement Corrosion ◽  
Shear Tests ◽  
Accelerated Corrosion ◽  
Corrosion Rates

In this study, shear tests were conducted to investigate the effects of longitudinal reinforcement corrosion on the shear capacity of reinforced concrete (RC) members with transverse reinforcement. To this end, a total of eight test specimens were fabricated, and the corrosion rates and anchorage details of rebars were set as test variables. In addition, an accelerated corrosion technique was used to introduce corrosion into the longitudinal reinforcement without corroding shear reinforcement. The test results indicated that the capacities of the specimens in which tension reinforcement was not properly anchored at the ends of the members decreased rapidly at high corrosion rates, whereas the capacities of the specimens in which tension reinforcement was properly anchored by hooks were similar to or higher than those of the non-corroded specimens, despite bond loss caused by corrosion.

Size effect on shear strength of reinforced concrete beams with tension reinforcement ratio

2016 ◽  
Vol 20 (4) ◽  
pp. 582-594 ◽  
Author(s):  
Chan-Yu Jeong ◽  
Hyeong-Gook Kim ◽  
Sang-Woo Kim ◽  
Kang-Seok Lee ◽  
Kil-Hee Kim
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Size Effect ◽  
Concrete Beams ◽  
Reinforcement Ratio ◽  
Reinforced Concrete Beams ◽  
Shear Tests ◽  
Effective Depth ◽  
Compressive Strength Of Concrete ◽  
Experimental Researches

It is well known that shear stress at peak of reinforced concrete beams decreases with increasing effective depth. Thus, several existing design codes and models have included various forms of formulas considering the size effect on shear strength of reinforced concrete beams; however, past experimental researches show that tension reinforcement ratio is also associated with the shear strength of reinforced concrete beams. To examine the effect of tension reinforcement ratio and effective depth on shear strength of reinforced concrete beams, this study has conducted experiments in which the effective depth (150, 300, 500, and 780 mm) and tension reinforcement ratio (1%, 2%, and 3%) are employed as variables. Besides, a formula for the shear strength considering both variables is proposed based on data samples collected from the present experiment and previous research. The proposed formula gives predictions comparable to the results of existing shear tests. Furthermore, rational predictions are made for effective depth of beams, compressive strength of concrete, shear span-to-depth ratio, and even tension reinforcement ratio exceeding 3%.

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.

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