scholarly journals SHEAR CAPACITY OF SUSTAINABLE LIGHT WEIGHT CONCRETE BEAMS

2021 ◽  
Vol 25 (02) ◽  
pp. 36-45
Author(s):  
Aseel Q. Makhool ◽  
◽  
Wissam K. Alsaraj ◽  
Luma A. Zghair ◽  
◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Steel Fiber ◽  
Lightweight Concrete ◽  
Concrete Beams ◽  
Shear Resistance ◽  
Shear Capacity ◽  
Steel Fibers ◽  
Reinforced Concrete Beams ◽  
Light Weight ◽  
Iron Filing

This Lightweight concrete is one of the important types familiar of concrete, as the local stone Attapulgite was used as aggregate after treating it with a solution of minors, then it was used in pouring five -reinforced concrete beams by adding steel fiber and iron filing separately with two percentages of 0.5 and 1, these beams were examined to determine the shear capacity. The results showed that iron filing by 1% improve the mechanical properties of concrete and similar to that of using steel fibers, but with a minimum effect. The results also showed that adding 1% of steel filing improves the maximum shear resistance and the first cracking resistance of the concrete by 38%.

scholarly journals SHEAR CAPACITY OF SUSTAINABLE LIGHT WEIGHT CONCRETE BEAMS

2021 ◽  
Vol 25 (02) ◽  
pp. 36-45
Author(s):  
Aseel Q. Makhool ◽  
◽  
Wissam K. Alsaraj ◽  
Luma A. Zghair ◽  
◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Steel Fiber ◽  
Lightweight Concrete ◽  
Concrete Beams ◽  
Shear Resistance ◽  
Shear Capacity ◽  
Steel Fibers ◽  
Reinforced Concrete Beams ◽  
Light Weight ◽  
Iron Filing

This Lightweight concrete is one of the important types familiar of concrete, as the local stone Attapulgite was used as aggregate after treating it with a solution of minors, then it was used in pouring five -reinforced concrete beams by adding steel fiber and iron filing separately with two percentages of 0.5 and 1, these beams were examined to determine the shear capacity. The results showed that iron filing by 1% improve the mechanical properties of concrete and similar to that of using steel fibers, but with a minimum effect. The results also showed that adding 1% of steel filing improves the maximum shear resistance and the first cracking resistance of the concrete by 38%.

Study on Retrofitting and Strengthening of Reinforced Concrete Beams Using Fibrous Concrete

2021 ◽  
Vol 9 (8) ◽  
pp. 1676-1684
Author(s):  
Natalia Sharma
Keyword(s):  
Mechanical Properties ◽  
Reinforced Concrete ◽  
Steel Fiber ◽  
Concrete Beams ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Reinforced Concrete Beams ◽  
Cement Matrix ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete

Abstract: Reinforced concrete structures are frequently in need of repair and strengthening as a result of numerous environmental causes, ageing, or material damage under intense stress conditions, as well as mistakes made during the construction process. RC structures are repaired using a variety of approaches nowadays. The usage of FRC is one of the retrofitting strategies. Steel fiber reinforced concrete (SFRC) was used in this investigation because it contains randomly dispersed short discrete steel fibers that operate as internal reinforcement to improve the cementitious composite's characteristics (concrete). The main rationale for integrating small discrete fibers into a cement matrix is to reduce the amount of cement used. The principal reason for incorporating short discrete fibers into a cement matrix is to reduce cracking in the elastic range, increase the tensile strength and deformation capacity and increase the toughness of the resultant composite. These properties of SFRC primarily depend upon length and volume of Steel fibers used in the concrete mixture. In India, the steel fiber reinforced concrete (SFRC) has seen limited applications in several structures due to the lack of awareness, design guidelines and construction specifications. Therefore, there is a need to develop information on the role of steel fibers in the concrete mixture. The experimental work reported in this study includes the mechanical properties of concrete at different volume fractions of steel fibers. These mechanical properties include compressive strength, split tensile strength and flexural strength and to study the effect of volume fraction and aspect ratio of steel fibers on these mechanical properties. However, main aim of the study was significance of reinforced concrete beams strengthened with fiber reinforced concrete layer and to investigate how these beams deflect under strain. The objective of the investigation was finding that applying FRC to strengthen beams enhanced structural performance in terms of ultimate load carrying capacity, fracture pattern deflection, and mode of failure or not.

scholarly journals Influence of Fiber Content on Shear Capacity of Steel Fiber-Reinforced Concrete Beams

Fibers ◽  
2019 ◽  
Vol 7 (12) ◽  
pp. 102 ◽  
Author(s):  
Juan Andres Torres ◽  
Eva O.L. Lantsoght
Keyword(s):  
Reinforced Concrete ◽  
Steel Fiber ◽  
Concrete Beams ◽  
Shear Capacity ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Reinforced Concrete Beams ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Fiber Volume

For shear-critical structural elements where the use of stirrups is not desirable, such as slabs or beams with reinforcement congestion, steel fibers can be used as shear reinforcement. The contribution of the steel fibers to the shear capacity lies in the action of the steel fibers bridging the shear crack, which increases the shear capacity and prevents a brittle failure mode. This study evaluates the effect of the amount of fibers in a concrete mix on the shear capacity of steel fiber-reinforced concrete beams with mild steel tension reinforcement and without stirrups. For this purpose, 10 beams were tested. Five different fiber volume fractions were studied: 0.0%, 0.3%, 0.6%, 0.9%, and 1.2%. For each different steel fiber concrete mix, the concrete compressive strength was determined on cylinders and the tensile strength was determined in a flexural test on beam specimens. Additionally, the influence of fibers on the shear capacity was analyzed based on results reported in the literature, as well as based on the expressions derived for estimating the shear capacity of steel fiber-reinforced concrete beams. The outcome of these experiments is that a fiber percentage of 1.2% or fiber factor of 0.96 can be used to replace minimum stirrups according to ACI 318-14 and a 0.6% fiber volume fraction or fiber factor of 0.48 to replace minimum stirrups according to Eurocode 2. A fiber percentage of 1.2% or fiber factor of 0.96 was observed to change the failure mode from shear failure to flexural failure. The results of this study support the inclusion of provisions for steel fiber-reinforced concrete in building codes and provides recommendations for inclusion in ACI 318-14 and Eurocode 2, so that a wider adoption of steel fiber reinforced concrete can be achieved in the construction industry.

scholarly journals Influence of Fiber Content on Shear Capacity of Steel Fiber Reinforced Concrete Beams

2019 ◽  
Author(s):  
Juan Andres Torres ◽  
Eva O.L. Lantsoght
Keyword(s):  
Reinforced Concrete ◽  
Steel Fiber ◽  
Concrete Beams ◽  
Shear Capacity ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Reinforced Concrete Beams ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Fiber Volume

For shear-critical structural elements where the use of stirrups is not desirable, such as slabs or beams with reinforcement congestion, steel fibers can be used as shear reinforcement. The contribution of the steel fibers to the shear capacity lies in the action of the steel fibers bridging the shear crack, which increases the shear capacity and prevents a brittle failure mode. This study evaluates the effect of the amount of fibers in a concrete mix on the shear capacity of steel fiber reinforced concrete beams with mild steel tension reinforcement and without stirrups. For this purpose, twelve beams were tested. Five different fiber volume fractions were studied: 0.0%, 0.3%, 0.6%, 0.9%, and 1.2%. For each different steel fiber concrete mix, the concrete compressive strength was determined on cylinders and the tensile strength was determined in a flexural test on beam specimens. Additionally, the influence of fibers on the shear capacity is analyzed based on results reported in the literature, as well as based on the expressions derived for estimating the shear capacity of steel fiber reinforced concrete beams. The outcome of these experiments is that a fiber percentage of 1.2% or fiber factor of 0.96 can be used to replace minimum stirrups according to ACI 318-14 and a 0.6% fiber volume fraction or fiber factor of 0.48 to replace minimum stirrups according to Eurocode 2. A fiber percentage of 1.2% or fiber factor of 0.96 was observed to change the failure mode from shear failure to flexural failure. The results of this presented study support the inclusion of provisions for steel fiber reinforced concrete in building codes and provides recommendations for inclusion in ACI 318-14 and Eurocode 2, so that a wider adoption of steel fiber reinforced concrete can be achieved in the construction industry.

scholarly journals Influence of Steel Fiber on the Shear Strength of a Concrete Beam

2018 ◽  
Vol 4 (7) ◽  
pp. 1501 ◽  
Author(s):  
Ali Ammar Hameed ◽  
Mohannad Husain Al-Sherrawi
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Concrete Beam ◽  
Shear Failure ◽  
Steel Fiber ◽  
Concrete Beams ◽  
Shear Capacity ◽  
Steel Fibers ◽  
Reinforced Concrete Beams ◽  
Shear Reinforcement

The shear failure in a concrete beam is a brittle type of failure. The addition of steel fibers in a plain concrete mix helps to bridge and restrict the cracks formed in the brittle concrete under applied loads, and enhances the ductility of the concrete. In this research an attempt was made to investigate the behavior and the ultimate shear strength of hooked end steel fiber reinforced concrete beams without traditional shear reinforcement. Four simply-supported reinforced concrete beams with a shear span-to-depth ratio of about 3.0 were tested under two-point loading up to failure. Steel fibers volumetric fractions that used were 0.0, 0.5, 0.75 and 1.0%. Test results indicated that using 1.0% volume fraction of hooked steel fiber led to exclude shear failure and enhanced the use of steel fibers as shear reinforcement in concrete beams. The results also showed that a concrete beam with hooked steel fiber provided higher post-flexural-cracking stiffness, an increase in the shear capacity and energy absorption and an increase in the maximum concrete and steel reinforcement strains.

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 Experiment and Analysis of Mechanical Properties of Lightweight Concrete Prefabricated Building Structure Beams

2022 ◽  
Vol 16 (1) ◽  
Author(s):  
Yingguang Fang ◽  
Yafei Xu ◽  
Renguo Gu
Keyword(s):  
Mechanical Properties ◽  
Concrete Beam ◽  
Lightweight Concrete ◽  
Concrete Beams ◽  
Virtual Work ◽  
Plain Concrete ◽  
Reinforced Concrete Beams ◽  
Beam Deflection ◽  
Building Structure ◽  
Foamed Concrete

AbstractRecent years have witnessed that the prefabricated concrete structure is in the widespread use of building structures. This structure, however, still has some weaknesses, such as excessive weight of components, high requirements for construction equipment, difficult alignment of nodes, and poor installation accuracy. In order to handle the problems mentioned above, the prefabricated component made of lightweight concrete is adopted. At the same time, this prefabricated component is beneficial to reducing the load of the building structure itself and improving the safety and economy of the building structure. Nevertheless, it is rarely found that the researches and applications of lightweight concrete for stressed members are conducted. In this context, this paper replaces ordinary coarse aggregate with lightweight ceramsite or foam based on the C60 concrete mix ratio so as to obtain a mix ratio of C40 lightweight concrete that meets the engineering standards. Besides, ceramsite concrete beams and foamed concrete beams are fabricated. Moreover, through three-point bending tests, this paper further explores the mechanical properties of lightweight concrete beams and plain concrete beams during normal use conditions. As demonstrated in the results, the mechanical properties of the foamed concrete beam are similar to those of the plain concrete beam. Compared to plain concrete beams, the density of foamed concrete beams was lower by 23.4%; moreover, the ductility and toughness of foamed concrete were higher by 13% and 3%, respectively. However, in comparison with the plain concrete beam, the mechanical properties of the ceramsite concrete beam have some differences, with relatively large dispersion and obvious brittle failure characteristics. Moreover, in consideration of the nonlinear deformation characteristics of reinforced concrete beams, the theoretical calculation value of beam deflection was given in this paper based on the assumption of flat section and the principle of virtual work. The theoretically calculated deflection values of ordinary concrete beams and foamed concrete beams are in good agreement with the experimental values under normal use conditions, verifying the rationality and effectiveness of the calculation method. The research results of this paper can be taken as a reference for similar engineering designs.

scholarly journals Effect of fiber amount and stirrup ratio on shear resistance of steel fiber reinforced concrete deep beams

2021 ◽  
Vol 15 (2) ◽  
pp. 1-13
Author(s):  
Thang Do-Dai ◽  
Duong T. Tran ◽  
Long Nguyen-Minh
Keyword(s):  
Reinforced Concrete ◽  
Steel Fiber ◽  
Shear Crack ◽  
Shear Resistance ◽  
Shear Capacity ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Experimental Program ◽  
Deep Beam ◽  
Deep Beams

This paper deals with the effect of steel fiber amounts and the interaction between the fiber amount and stirrup ratio on the shear behavior and capacity of reinforced concrete (RC) deep beams with steel fibers. The experimental program was carried out on twelve deep beams with different fiber amounts (0, 30, 40, and 65 kg/m3) and stirrup ratios (0.1, 0.15, and 0.25%). The test results have shown that the use of steel fibers increased the shear resistance (up to 55%), reduced the shear crack width (up to 11 times) and deflection (up to 57%) of the tested deep beams. Also, it was found that using unsuitable steel fiber amount and stirrup ratio would reduce the efficiency of the fibers in a deep beam due to the interaction between the fibers and stirrups. Increasing the stirrup ratio in a deep beam with a high amount of steel fibers can reduce the efficacy of the fibers in enhancing the shear capacity of the beam. The most cost-effective steel fiber amount was found to be around 30 to 45 kg/m3. Keywords: steel fibers; deep beam; shear capacity; fiber amount; stirrup ratio.

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