To see the other types of publications on this topic, follow the link: Shear strength, high performance concrete beams.
Journal articles on the topic 'Shear strength, high performance concrete beams'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Shear strength, high performance concrete beams.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Qi, Jianan, Xiaomeng Ding, Zhen Wang, and Yuqing Hu. "Shear strength of fiber-reinforced high-strength steel ultra-high-performance concrete beams based on refined calculation of compression zone depth considering concrete tension." Advances in Structural Engineering 22, no. 8 (February 21, 2019): 2006–18. http://dx.doi.org/10.1177/1369433219829805.
Full textAbstract:
This article presents an experimental and theoretical investigation on the shear behavior of fiber-reinforced ultra-high-performance concrete beams reinforced with high-strength steel. The test parameters included the fiber volume fraction, fiber type, and stirrup ratio. The test results indicate that the shear failure in ultra-high-performance concrete beams is not brittle and catastrophic but has ductility characteristics. A moderate quantity of stirrups can significantly improve the shear behavior of ultra-high-performance concrete beams, as reflected in the thorough propagation of cracks in both shear span and pure bending zone. The depth of the compression zone considering concrete tension was derived based on the deformation compatibility and force equilibrium equations for both serviceability limit state and ultimate limit state. The comparison of the proposed method and classical beam theory shows that the concrete tension should not be neglected in the serviceability limit state analysis. After cracking, the concrete tension can be neglected for simplicity when the beam is heavily reinforced and should be considered when the beam is lightly reinforced. Then, a shear strength model was established based on Rankine’s failure criteria, the truss model, and Association Francaise de Génie Civil-Sétra. Finally, the proposed shear strength equation was verified by the test results and compared with other shear strength equations.
2
Chabib, H. El, M. Nehdi, and A. Saïd. "Predicting the effect of stirrups on shear strength of reinforced normal-strength concrete (NSC) and high-strength concrete (HSC) slender beams using artificial intelligence." Canadian Journal of Civil Engineering 33, no. 8 (August 1, 2006): 933–44. http://dx.doi.org/10.1139/l06-033.
Full textAbstract:
The exact effect that each of the basic shear design parameters exerts on the shear capacity of reinforced concrete (RC) beams without shear reinforcement (Vc) is still unclear. Previous research on this subject often yielded contradictory results, especially for reinforced high-strength concrete (HSC) beams. Furthermore, by simply adding Vc and the contribution of stirrups Vs to calculate the ultimate shear capacity Vu, current shear design practice assumes that the addition of stirrups does not alter the effect of shear design parameters on Vc. This paper investigates the validity of such a practice. Data on 656 reinforced concrete beams were used to train an artificial neural network model to predict the shear capacity of reinforced concrete beams and evaluate the performance of several existing shear strength calculation procedures. A parametric study revealed that the effect of shear reinforcement on the shear strength of RC beams decreases at a higher reinforcement ratio. It was also observed that the concrete contribution to shear resistance, Vc, in RC beams with shear reinforcement is noticeably larger than that in beams without shear reinforcement, and therefore most current shear design procedures provide conservative predictions for the shear strength of RC beams with shear reinforcement.Key words: analysis, artificial intelligence, beam depth, compressive strength, modeling, shear span, shear strength.
3
Yun, Ying Wei, Qin Luo, Il Young Jang, Shan Shan Sun, and Jia Wei Zhang. "Experimental Research on the Ductility of High Performance Concrete Beams." Applied Mechanics and Materials 166-169 (May 2012): 1316–20. http://dx.doi.org/10.4028/www.scientific.net/amm.166-169.1316.
Full textAbstract:
Ductility is important in the design of reinforced concrete structures. In seismic design of reinforced concrete members, it is necessary to allow for relatively large ductility so that the seismic energy is absorbed to avoid shear failure or significant degradation of strength even after yielding of reinforcing steels in the concrete member occurs. This paper aims to present the basic data for the ductility evaluation of reinforced HPC (high performance concrete) beams. Accordingly, 10 flexural tests were conducted on full-scale structural concrete beam specimens having concrete compressive strength of 40, 60, and 70 MPa. The test results were then reviewed in terms of flexural capacity and ductility. The effect of concrete compressive strength, tension steel ratio, and shear span to beam depth ratio on ductility were investigated experimentally.
4
Pourbaba, Masoud, Hamed Sadaghian, and Amir Mirmiran. "A comparative study of flexural and shear behavior of ultra-high-performance fiber-reinforced concrete beams." Advances in Structural Engineering 22, no. 7 (January 23, 2019): 1727–38. http://dx.doi.org/10.1177/1369433218823848.
Full textAbstract:
In this research, the flexural and shear behavior of five locally developed ultra-high-performance fiber-reinforced concrete beams was experimentally investigated. Four-point loading tests were carried out on concrete specimens which were further compared with five normal-strength concrete beams constructed at the laboratory. The objective of this study is to assess the flexural and shear behavior of ultra-high-performance fiber-reinforced concrete beams and compare them with that of normal-strength beams and available equations in the literature. Results indicate underestimation of shear (up to 2.71 times) and moment capacities (minimum 1.27 times, maximum 3.55 times) by most of the equations in beams with low-reinforcement ratios. Finally, results reveal that the experimental flexural and shear capacities of ultra-high-performance fiber-reinforced concrete specimens are up to 3.5 times greater than their normal-strength counterpart specimens.
5
Ibrahim, Basil, Moussa Leblouba, Salah Altoubat, and Samer Barakat. "Shear Strength of Externally U-Bonded Carbon Fiber-Reinforced Polymer High-Strength Reinforced Concrete." Materials 14, no. 13 (June 30, 2021): 3659. http://dx.doi.org/10.3390/ma14133659.
Full textAbstract:
In this paper, we investigate the contribution of Fiber-Reinforced Polymer (FRP) to the load-carrying capacity of shear-strengthened Reinforced Concrete (RC) beams. Specifically, the investigation is focused on the FRP’s contribution in the presence and absence of shear stirrups. To this end, two sets of full-scale RC beam specimens were tested to failure in a simply supported setup. Set 1 consisted of specimens without shear stirrups whereas Set 2 included steel stirrups spaced at 170 mm. One and two layers of FRP discrete strips were bonded to the beams in a U-jacketing configuration. To investigate the contribution of FRP and its interaction with the stirrups, two different locations were considered when bonding the FRP strips: between the stirrups (referred to as Off-beams) and at the same level of the stirrups (referred to as On). Results of the experimental program showed that strengthening the beams with two layers of FRP does not necessarily translate to improved capacity. Furthermore, the location of FRP strips with respect to the location of shear stirrups has an influence on the beam’s overall behavior, especially its displacement ductility. This is an important parameter to consider to avoid premature failure of RC members. Test results were then used to assess the performance and accuracy of the predictions of ACI PRC-440.2-17 and fib-TG9.3. Both design codes were found to be conservative with an average prediction-to-test ratio of 0.7.
6
Yuan, Tian-Feng, Se-Hee Hong, Hyun-Oh Shin, and Young-Soo Yoon. "Bond Strength and Flexural Capacity of Normal Concrete Beams Strengthened with No-Slump High-Strength, High-Ductility Concrete." Materials 13, no. 19 (September 23, 2020): 4218. http://dx.doi.org/10.3390/ma13194218.
Full textAbstract:
This study investigates the flexural behavior of normal-strength concrete (NSC) beams that were strengthened with no-slump, high-strength, high-ductility concrete (NSHSDC). A set of slant shear tests was performed to investigate the initial performance of the NSC substrate strengthened with NSHSDC. Slant shear tests considered two types of roughness of interface and five angles of the interface between NSC and NSHSDC. The test results showed that except for specimens with a 75° interface angle, the specimens with high roughness were conformed to the properties (14–21 MPa for 28 days) of the ACI Committee 546 recommendation. For flexural strength tests, NSC beams strengthened with an NSHSDC jacket on the top and bottom sides, three sides, and four sides resulted in strength increments of about 8%, 29%, and 40%, respectively, compared to the beams without NSHSDC jacket. Therefore, the use of NSHSDC is an effective method to improve the performance of NSC beams and is recommended for strengthening reinforced concrete members.
7
Mahmood, Enas M., Abbas A. Allawi, and Ayman El-Zohairy. "Flexural Performance of Encased Pultruded GFRP I-Beam with High Strength Concrete under Static Loading." Materials 15, no. 13 (June 27, 2022): 4519. http://dx.doi.org/10.3390/ma15134519.
Full textAbstract:
There is an interesting potential for the use of GFRP-pultruded profiles in hybrid GFRP-concrete structural elements, either for new constructions or for the rehabilitation of existing structures. This paper provides experimental and numerical investigations on the flexural performance of reinforced concrete (RC) specimens composite with encased pultruded GFRP I-sections. Five simply supported composite beams were tested in this experimental program to investigate the static flexural behavior of encased GFRP beams with high-strength concrete. Besides, the effect of using shear studs to improve the composite interaction between the GFRP beam and concrete as well as the effect of web stiffeners of GFRP were explored. Encasing the GFRP beam with concrete enhanced the peak load by 58.3%. Using shear connectors, web stiffeners, and both improved the peak loads by 100.6%, 97.3%, and 130.8%, respectively. The GFRP beams improved ductility by 21.6% relative to the reference one without the GFRP beam. Moreover, the shear connectors, web stiffeners, and both improved ductility by 185.5%, 119.8%, and 128.4%, respectively, relative to the encased reference beam. Furthermore, a non-linear Finite Element (FE) model was developed and validated by the experimental results to conduct a parametric study to investigate the effect of the concrete compressive strength and tensile strength of the GFRP beam. The developed FE model provided good agreement with the experimental results regarding deformations and damaged patterns.
8
Demakos, Constantinos B., Constantinos C. Repapis, and Dimitros P. Drivas. "Experimental Investigation of Shear Strength for Steel Fibre Reinforced Concrete Beams." Open Construction & Building Technology Journal 15, no. 1 (May 19, 2021): 81–92. http://dx.doi.org/10.2174/1874836802115010081.
Full textAbstract:
Aims: The aim of this paper is to investigate the influence of the volume fraction of fibres, the depth of the beam and the shear span-to-depth ratio on the shear strength of steel fibre reinforced concrete beams. Background: Concrete is a material widely used in structures, as it has high compressive strength and stiffness with low cost manufacturing. However, it presents low tensile strength and ductility. Therefore, through years various materials have been embedded inside it to improve its properties, one of which is steel fibres. Steel fibre reinforced concrete presents improved flexural, tensile, shear and torsional strength and post-cracking ductility. Objective: A better understanding of the shear performance of SFRC could lead to improved behaviour and higher safety of structures subject to high shear forces. Therefore, the influence of steel fibres on shear strength of reinforced concrete beams without transverse reinforcement is experimentally investigated. Methods: Eighteen concrete beams were constructed for this purpose and tested under monotonic four-point bending, six of which were made of plain concrete and twelve of SFRC. Two different aspect ratios of beams, steel fibres volume fractions and shear span-to-depth ratios were selected. Results: During the experimental tests, the ultimate loading, deformation at the mid-span, propagation of cracks and failure mode were detected. From the tests, it was shown that SFRC beams with high volume fractions of fibres exhibited an increased shear capacity. Conclusion: The addition of steel fibres resulted in a slight increase of the compressive strength and a significant increase in the tensile strength of concrete and shear resistance capacity of the beam. Moreover, these beams exhibit a more ductile behaviour. Empirical relations predicting the shear strength capacity of fibre reinforced concrete beams were revised and applied successfully to verify the experimental results obtained in this study.
9
Hou, Li-Qun, Shi-Cai Chen, Wei-Ming Yan, and Kang-Suk Kim. "Mechanical performance of space sandwich joints under bidirectional cyclic loading." Advances in Structural Engineering 22, no. 1 (May 31, 2018): 69–80. http://dx.doi.org/10.1177/1369433218778403.
Full textAbstract:
In high-rise buildings with high-strength concrete column and normal-strength concrete floor, the beams and slabs are usually cast in a continuous fashion through the beam–column joint to simplify construction, and this results in the lower strength concrete at the beam–column joint core (sandwich joint). It will influence the capacity of the joint. In this article, three groups of three-dimensional specimens consisting of sandwich joint specimens and corresponding traditional joint specimens were tested under bidirectional reversed cyclic loads to investigate seismic performance, including the failure mode, ductility, energy dissipation, and deformation. The test results show that the beam–column joint core can be cast with normal-strength concrete when the column concrete strength is less than 1.5 times that of the beam. However, when the ratio exceeds 1.5, the failure mode of the joint may change from beams flexural failure to joint shear failure and additional strengthening measures should be taken. Finally, the formula for calculating shear capacity of the three-dimensional sandwich joints is presented, and the predictions are compared to the experimental results.
10
Kamonna, Hayder H. H., Qasim M. Shakir, and Haider A. Al-Tameemi. "Behavior of High-Strength Self-Consolidated Reinforced Concrete T-Deep Beams." Open Construction and Building Technology Journal 14, no. 1 (May 23, 2020): 51–69. http://dx.doi.org/10.2174/1874836802014010051.
Full textAbstract:
Background: When a beam is loaded on two opposite faces and the beam’s depth is increased such that either the span-to-depth ratio is smaller than four or the shear-span-to-depth ratio is less than two, it will behave like a deep beam. Strain distribution in deep beams is different from that of ordinary beams because it is nonlinear along with the beam depth. If the beam is cast monolithically with a slab in the slab–beam system, it is considered a T-deep beam. The behavior of the resulting member is more complicated. Objective: The effect of flange width on the behavior of high-strength self-consolidated reinforced concrete T-deep beams was investigated. Methods: Experimental and numerical studies were conducted. Two shear span-to-depth ratios (1.25 and 0.85) were adopted for two groups. Each group consisted of four specimens: one rectangular beam that served as a reference beam and three flanged beams with flange widths of 440, 660 and 880 mm. All specimens had an overall depth of 450 mm, a width of 160 mm and a total length of 1600 mm. The tests were performed under a two-point load with a clear span of 1400 mm. A nonlinear analysis was also performed using ANSYS software. Results: Throughout the study, the performance of the T-deep beams has been investigated in terms of cracking loads, failure loads, modes of failure, loading history, rate of widening of cracks and ductility index. Results revealed that such parameters have a different ranges of effect on the response of T-deep beams. Calibration of the ANSYS model has been done by comparing results of load-deflection curves, cracking and failure loads with that obtained experimentally. Conclusion: The study’s results indicated that increasing the flange width yielded an 88% improvement in the failure load and an approximately 68% improvement in the cracking load. This positive effect of flange width on the failure load was more pronounced in beams with higher shear span to- depth ratios and flange widths of 660 mm. In addition, the beam’s ductility was improved, especially in cases corresponding to a higher shear span-to-depth ratio. The finite element simulation showed good validation in terms of the load-deflection curve with a maximum failure load difference of 9%. In addition, the influence of longitudinal steel reinforcement on the behavior of such members was studied. Some parameters that reflect the effect of changing the flange width on the behavior of deep beams were also presented. Increasing the flange width is more effective when using normal strength concrete than when using high-strength concrete in terms of cracking load, beam stiffness, and failure load.
11
Bae, Baek-Il, Moon-Sung Lee, Chang-Sik Choi, Hyung-Suk Jung, and Hyun-Ki Choi. "Evaluation of the Ultimate Strength of the Ultra-High-Performance Fiber-Reinforced Concrete Beams." Applied Sciences 11, no. 7 (March 25, 2021): 2951. http://dx.doi.org/10.3390/app11072951.
Full textAbstract:
Evaluation of the ultimate strength for the UHPFRC (ultra-high-performance fiber-reinforced concrete) flexural members was conducted. In this study, an experimental program about UHPFRC beams was conducted with the effect of fiber volume fraction, shear span to depth ratio, and compressive strength of matrix as the main variables. Among them, it was found that fiber volume fraction was the variable that had the greatest influence on the ultimate strength. The inclusion of 2% volume fraction steel fiber increases the shear and flexural strength of UHPFRC beams significantly. In particular, steel fiber inclusion changed the mode of failure of beams from diagonal shear failure into flexural failure. For the classification of failure patterns, the ultimate flexural strength and shear strength of UHPFRC members were evaluated using the current design code and UHPC guidelines. Flexural ultimate strength was affected by the size and shape of the stress block and consideration of the matrix’s tensile strength. For the accurate shear strength prediction of UHPFRC beams, the tensile strength of the high strength matrix and the effect of steel fiber should be considered.
12
Kodsy, Antony, and George Morcous. "Shear Strength of Ultra-High-Performance Concrete (UHPC) Beams without Transverse Reinforcement: Prediction Models and Test Data." Materials 15, no. 14 (July 8, 2022): 4794. http://dx.doi.org/10.3390/ma15144794.
Full textAbstract:
The use of Ultra-High-Performance Concrete (UHPC) in beams has been growing rapidly in the past two decades due to its superior mechanical and durability properties compared to conventional concrete. One of the areas of interest to designers is the elimination of transverse reinforcement as it simplifies beam fabrication/construction and could result in smaller and lighter beams. UHPC has a relatively high post-cracking tensile strength due to the presence of steel fibers, which enhance its shear strength and eliminate the need for transverse reinforcement. In this paper, UHPC shear test data were collected from the literature to study the effect of the following parameters on the shear strength of UHPC beams without transverse reinforcement: compressive strength, tensile strength, level of prestressing, longitudinal reinforcement ratio, and fiber volume fraction. Statistical analysis of test data indicated that level of prestressing and tensile strength are the most significant parameters for prestressed UHPC beams, whereas longitudinal reinforcement ratio and tensile strength are the most significant parameters for non-prestressed UHPC beams. Additionally, shear strength of the tested UHPC beams was predicted using five models: RILEM TC 162-TDF, 2003, fib Model Code, 2010, French Standard NF P 18-710, 2016, PCI-UHPC Structures Design Guide, 2021, and Draft of AASHTO Guide Specification for Structural Design with UHPC, 2021. Comparing measured against predicted shear strength indicated that the French Standard model provides the closest prediction with the least scatter, where the average measured-to-predicted strength was 1.1 with a standard deviation of 0.38. The Draft of AASHTO provided the second closest prediction where the average measured-to-predicted strength was 1.3 with a standard deviation of 0.64. The other three models underestimated the shear strength.
13
Leng, Yubing, and Xiaobing Song. "Application of steel-concrete-steel sandwich deep beams into coupled shear walls." Advances in Structural Engineering 22, no. 1 (June 27, 2018): 214–22. http://dx.doi.org/10.1177/1369433218783297.
Full textAbstract:
Coupled shear walls are widely used as the primary lateral load resisting element in high-rise buildings. But the coupling beams, which are often designed as deep members, usually suffer from brittle shear failure. The steel-concrete-steel sandwich deep beams showed high bearing capacity and great ductile performance during shear failure. Therefore, it is proposed that the steel-concrete-steel members can be used into deep coupling beams instead of conventional reinforced concrete members, to improve the shear strength and deformability. The shear failure of steel-concrete-steel deep beams is characterized by plastic yielding of the outer steel plates in the triangular areas, rather than concrete diagonal crushing. Reliable shear transfer paths are maintained by the interaction between the outer steel plates and the diagonal concrete struts, so excellent strength and ductile performance can be expected after critical diagonal cracking. The triangular failure areas are able to dissipate seismic energy, thus effectively avoiding overall collapse. The shear strength of steel-concrete-steel deep coupling beams is developed with simple expressions.
14
Hakim, S. J. S., M. A. H. Mohd Rodzi, S. S. Ayop, S. Shahidan, S. N. Mokhatar, and N. Salleh. "Shear Strengthening of Reinforced Concrete Beams Using Fibre Reinforced Polymer: A Critical Review." IOP Conference Series: Materials Science and Engineering 1200, no. 1 (November 1, 2021): 012015. http://dx.doi.org/10.1088/1757-899x/1200/1/012015.
Full textAbstract:
Abstract The primary purpose of reinforcing bar stirrups in a reinforced concrete beam is to improve shear strength. The FRP system may significantly improve a concrete beam’s ultimate shear strength, serviceability, and ductility. The application of FRP for the repair and reinforcement of the structures has become very popular due to its low weight, high tensile strength, and simplicity of installation on uneven surfaces. FRP material outperforms other traditional materials in strengthening applications due to its high strength-to-weight and stiffness-to-weight ratios, resistance to corrosion, and ease of handling. The overall objective of this research is to investigate and improve the understanding of the recent research in the area of shear FRP strengthening of reinforced concrete beams. In this paper, recent publications were reviewed to see how different anchoring procedures, different factors that affect FRP performance and different failure scenarios affect the shear strengthening of concrete beams. The benefits and limits of FRP systems, as well as some current research trends are discussed in this project. From the research, it can be stated that type of anchorage technique and different parameter give a different impact to failure mode of the beam.
15
Liu, Sheng Bing, Li Hua Xu, Hai Lin Lu, and Hao Tan. "Design Method of Shear Resistance of Hybrid Fiber Reinforced High Performance Concrete Deep Beams." Applied Mechanics and Materials 477-478 (December 2013): 686–89. http://dx.doi.org/10.4028/www.scientific.net/amm.477-478.686.
Full textAbstract:
In order to study the shear resistance and design method of hybrid fiber (steel fiber and polypropylene fiber) reinforced high performance concrete deep beams, the shear tests were conducted according to the orthogonal experimental design. The contributory factors such as the characteristic parameters of steel fiber (types, volume fraction, aspect ratio), the volume fraction of polypropylene fiber, the ratio of web horizontal reinforcement and the ratio of web vertical reinforcement were analyzed. Results illuminate that shear failure mode of hybrid fiber reinforced HPC deep beams are splitting failure and diagonal compression failure. Hybrid fiber can notably increase the diagonal cracking strength and shear strength of HPC deep beams. The diagonal cracking strength is increased by 5.6%~83.8% while the shear strength is increased by15.6%~35.2%. A formula to calculate the shear resistance of hybrid fiber reinforced HPC deep beams is put forward based on spatial strut-and-tie mode and splitting failure. Meantime test verification is carried out and the calculated results are satisfied.
16
Shi, Qi Yin, and Li Li Liu. "Research on the Shear Strength of High-Strength Concrete Beams with Web Bars by Concentrated Load." Advanced Materials Research 859 (December 2013): 70–75. http://dx.doi.org/10.4028/www.scientific.net/amr.859.70.
Full textAbstract:
Based on the previous results on the experimental study of shear performance of high-strength concrete beam and the application of mathematical statistics theory, the page establish the shearing strength formula of high strength concrete beams under concentrated load . Comparing regression formula and GB50010-2010 calculated value with the experimental results respectively, it shows that the ultimate strength calculated by regression analysis matches with the experimental results well, but GB2010 calculated results is unsafe.
17
Youssf, Osama, Reza Hassanli, Julie E. Mills, Xing Ma, and Yan Zhuge. "Cyclic Performance of Steel–Concrete–Steel Sandwich Beams with Rubcrete and LECA Concrete Core." Journal of Composites Science 3, no. 1 (January 7, 2019): 5. http://dx.doi.org/10.3390/jcs3010005.
Full textAbstract:
Due to the structural and economic features of steel–concrete–steel (SCS) structural systems compared with conventional reinforced concrete ones, they are now used for a range of structural applications. Rubcrete, in which crumbed rubber from scrap tires partially replaces mineral aggregates in concrete, can be used instead of conventional concrete. Utilizing rubber waste in concrete potentially results in a more ductile lightweight concrete that can introduce additional features to the SCS structural members. This study aimed to explore different concrete core materials in SCS beams and the appropriate shear connectors required. In this study, four SCS sandwich beams were tested experimentally under incrementally increasing flexure cyclic loading. Each beam had a length of 1000 mm, and upper and lower steel plates with 3 mm thickness sandwiched the concrete core, which had a cross-section of 150 mm × 150 mm. Two of the beams were constructed out of Rubcrete core with welded and bolted shear connectors, while the other two beams were constructed with welded shear connectors and either conventional concrete or lightweight expanded clay aggregate (LECA) concrete cores. The performance of the SCS sandwich beams including damage pattern, failure mode, load-displacement response, and energy dissipation behavior was compared. The results showed that, while Rubcrete was able to provide similar concrete cracking behavior and strength to that of conventional concrete, LECA concrete degraded the strength properties of SCS. Using bolted shear connectors instead of welded ones caused a high number of cracks that resulted in a reduced ductility and deflection capacity of the beam before failure. The rubberized concrete specimen presented an improved ductility and deflection capacity compared with its conventional concrete counterpart.
18
Liu, Sheng Bing, and Lihua Xu. "Experimental Study on Shear Behavior of Hybrid Fiber Reinforced High Performance Concrete Deep Beams." Applied Mechanics and Materials 166-169 (May 2012): 664–69. http://dx.doi.org/10.4028/www.scientific.net/amm.166-169.664.
Full textAbstract:
In order to investigate the effect of steel fiber and polypropylene fiber on shear behavior of HPC deep beams, the shear tests were conducted on 18 different groups of deep beams with steel fiber and polypropylene fiber and 2 groups of HPC deep beams without fiber according to the orthogonal experiment. 6 factors, including the shape of steel fiber, the volume fraction of steel fiber, the aspect ratio of steel fiber, the volume fraction of polypropylene fiber, the ratio of web horizontal reinforcement and the ratio of web vertical reinforcement, were compared by direct-viewing analysis. Results illuminate that hybrid fibers greatly increase the diagonal cracking strength and shear strength of HPC deep beams. The aspect ratio of steel fiber plays the most important role in diagonal cracking strength whereas the ratio of web vertical reinforcement has minimum effect. Meanwhile the ratio of web horizontal reinforcement plays the most important role in shear strength whereas the volume fraction of polypropylene fiber has minimum effect. An anti-cracking capacity for inclined section calculation formula and a shear bearing capacity calculation formula for hybrid fiber reinforced HPC deep beams are put forward based on current code. Meantime test verification is carried out and the calculated results are satisfied.
19
Yun, Hyun-Do, Gwon-Young Jeong, and Won-Chang Choi. "Shear Strengthening of High Strength Concrete Beams That Contain Hooked-End Steel Fiber." Materials 15, no. 1 (December 21, 2021): 17. http://dx.doi.org/10.3390/ma15010017.
Full textAbstract:
Steel fiber has been used successfully in concrete mixtures to control volumetric changes, including shrinkage. However, the feasibility of the use of steel fiber has been restricted to nonstructural construction, such as ‘slab on ground’. Recently, researchers have attempted to expand the applications of steel fiber to replace structural reinforcement (rebar) and have shown promising results in its substitution for shear reinforcement. Few studies have been conducted to ensure the feasibility of using steel fiber in structural components, however. This experimental study was designed to investigate the shear performance of steel fiber-reinforced concrete beams using the tensile strength of steel fiber and the shear span-to-depth ratio as variables. The experimental results indicate that the tensile strength of steel fiber significantly affects the shear strength of steel fiber-reinforced concrete beams, regardless of the shear span-to-depth ratio, and that steel fiber can play a role in shear reinforcement of concrete beams.
20
Yao, Dali, Jinqing Jia, Feng Wu, and Fang Yu. "Shear performance of prestressed ultra high strength concrete encased steel beams." Construction and Building Materials 52 (February 2014): 194–201. http://dx.doi.org/10.1016/j.conbuildmat.2013.11.006.
Full text
21
Solhmirzaei, Roya, and Venkatesh Kodur. "A Numerical Model for Tracing Structural Response of Ultra-High Performance Concrete Beams." Modelling 2, no. 4 (October 1, 2021): 448–66. http://dx.doi.org/10.3390/modelling2040024.
Full textAbstract:
This paper presents a finite element-based numerical model for tracing the behavior of ultra-high performance concrete (UHPC) beams. The model developed in ABAQUS can account for stress–strain response of UHPC and reinforcing bar in both tension and compression, bond between concrete and reinforcing steel, and strain hardening effects in bars and UHPC and can trace the detailed response of UHPC beams in the entire range of loading. This model is validated by comparing predicted response parameters including load-strain, load-deflection, and crack propagation against experimental data governed from tests on UHPC beams with different reinforcement ratios, fiber volume fractions, and loading configurations (shear and flexural loading). The validated model is applied to quantify the contribution of stirrups and concrete to shear strength of beams so as to explore the feasibility of removing shear reinforcement in UHPC beams.
22
Yang, Chun, Ming Ji He, Jian Cai, Yan Sheng Huang, and Yi Wu. "Study on Mechanical Behaviors and Calculation of Shear Strength of Steel Truss Reinforced Concrete Deep Beams." Advanced Materials Research 243-249 (May 2011): 514–20. http://dx.doi.org/10.4028/www.scientific.net/amr.243-249.514.
Full textAbstract:
Based on strut-and-tie model (STM) in deep beams, steel truss reinforced concrete (STRC) deep beam was developed. Experimental investigations of mechanical performances of STRC deep beams were carried out, and results show that STRC deep beam is of high ultimate bearing capacity, large rigidity and good ductility; Strut-and-tie force transference model is formed in STRC deep beams, and loads can be transferred in the shortest and direct way. Then Steel reinforced concrete (SRC) strut-and-tie model (SSTM) for determining the shear strength of STRC deep beams is proposed. The contribution of SRC diagonal strut, longitudinal reinforcements, stirrups and web reinforcements to the shear strength of STRC deep beams are determined with consideration of softened effects of concrete, and for safe consideration, superposition theory is employed for SRC struts. Computer programs are developed to calculate the shear strength of STRC deep beams and verified by experimental results.
23
Zhou, Longyun, Xiaojun Li, and Qiushi Yan. "Performance of Grouting Sleeve-Connected Prefabricated Beams Subjected to Impact Loading." Buildings 12, no. 12 (December 6, 2022): 2146. http://dx.doi.org/10.3390/buildings12122146.
Full textAbstract:
The potential of accidental loads such as explosions and impacts cannot be overlooked given the widespread use of precast concrete (PC) buildings. However, research on the impact resistance of reinforced concrete precast beams is limited. In order to explore the dynamic behavior of PC beams connected by grouted sleeves under impact loads, this work developed a numerical model based on the finite element program LS-DYNA. First, the experimental process was described in detail, and the numerical model was evaluated and calibrated according to the experimental data. Then, parameters such as impact location, concrete strength of precast section and stirrup rate of cast-in-place area were studied. Finally, a simpler model based on equal high-frequency impulse impact force was suggested, and the viability of a single-degree-of-freedom model theory was proved for the dynamic analysis of PC simply supported beams subjected to impact loading. According to the findings, the interface of precast concrete and cast-in-place concrete is the weak point of the PC beam, which is prone to shear damage under impact loads. Second, when the middle of the cast-in-place part of the PC beam is impacted, wide cracks from the bottom to the top are quite likely to form. As a result, the most disadvantageous impact position for PC beams is in the middle of the cast-in-place portion. Although increasing the concrete strength of the precast section can reduce crack formation, it has minimal influence on the interface’s shear resistance. Furthermore, increasing the stirrup rate in the post-cast portion can increase the overall shear resistance of the PC beams.
24
Yuan, Fang, Wangren Wei, and Ren Hu. "Shear strengthening of reinforced concrete beams with high-strength steel wire and engineered cementitious composites." Advances in Structural Engineering 25, no. 1 (October 6, 2021): 158–70. http://dx.doi.org/10.1177/13694332211046346.
Full textAbstract:
Engineered cementitious composite (ECC) is a type of high-performance fibre-reinforced cementitious composite with good ductility and excellent crack control ability. It has attracted increasing attention as a structural repair material in severely corrosive environments. However, the strength improvement is limited when ECC is used alone for shear strengthening of existing reinforced concrete (RC) members, although its shear capacity is much higher than that of other brittle cementitious materials such as cement mortar. This study proposes a novel shear strengthening method for RC beams with both high load-carrying capacity and good durability through the combination of high-strength steel wire and an ECC layer. The shear behaviours of the beams were tested under static loading. The test results showed that the shear strength and the ultimate displacement were significantly improved through shear strengthening. A large number of fine cracks appeared on the ECC layer before the failure of the beams. The load-carrying capacity was reduced by pre-damage owing to the important role of the shear resistance of the concrete with respect to the total shear capacity. The shear strength of the strengthened beams cannot be accurately predicted by the current design code owing to the ignorance of the shear resistance of ECC.
25
Fang, Zhen, Shu Fang, and Feng Liu. "Experimental and Numerical Study on the Shear Performance of Short Stud Shear Connectors in Steel–UHPC Composite Beams." Buildings 12, no. 4 (March 31, 2022): 418. http://dx.doi.org/10.3390/buildings12040418.
Full textAbstract:
Steel–ultra-high-performance concrete (UHPC) composite beams offer numerous advantages, such as structural self-weight reduction, bending stiffness improvement, and tensile cracking limitation in slabs. However, few studies have focused on the shear performance of short stud shear connectors in steel–UHPC composite structures. To this end, push-out tests were carried out to evaluate the effect of slab thickness, stud diameter, and casting method on the failure mode, load–slip relationship, ultimate shear strength, shear stiffness, and ductility. The test results indicate that by increasing the slab thickness from 50 to 75 mm, the stud shear capacity and initial shear stiffness were improved by 11.38% and 23.28%, respectively. The stud shear capacity and initial shear stiffness for specimens with stud diameters of 25 mm were 1.29 and 1.23 times that of their 22-mm-diameter counterparts. In addition, adopting precast UHPC slabs could achieve comparative shear resistance (94.91%) but a better slip capacity (108.94%) than those containing conventional monolithic cast slabs. Based on the experimental results, a finite element (FE) model was established to reflect the plastic behavior of the tests and the damage process in the short stud shear connectors. Based on the validated FE model, a parameter study was then performed to further explore the influence of the stud diameter, stud tensile strength, steel beam tensile strength, monolithic slab concrete strength, precast slab concrete strength, and shear pocket concrete strength on the shear performance of short studs in steel–UHPC composite structures.
26
Lachemi, M., K. M. A. Hossain, and V. Lambros. "Shear resistance of self-consolidating concrete beams — experimental investigations." Canadian Journal of Civil Engineering 32, no. 6 (December 1, 2005): 1103–13. http://dx.doi.org/10.1139/l05-066.
Full textAbstract:
Self-consolidating concrete (SCC) is a new generation of high performance concrete known for its excellent deformability and high resistance to segregation and bleeding. Lack of information regarding in situ properties and structural performance of SCC is one of the main barriers to its acceptance in the construction industry. There is some concern among researchers and designers that SCC may not be strong enough in shear because of some uncertainties in mechanisms resisting shear — notably the aggregate interlock mechanism. Because of the presence of comparatively smaller amount of coarse aggregates in SCC, the fracture planes are relatively smooth as compared with normal concrete (NC) that may reduce the shear resistance of concrete by reducing the aggregate interlock between the fracture surfaces. The paper compares the shear resistance of SCC and NC based on the results of an experimental investigation on 18 flexurally reinforced beams without shear reinforcements. The test parameters include concrete type, maximum size of coarse aggregate, coarse aggregate content, and beam shear span-to-depth ratio. Shear strength, shear ductility, crack patterns, and failure modes of all experimental beams are compared to analyze the shear resistance mechanisms of SCC and NC beams in both pre- and post-cracking stages. The recommendations of this paper can be of special interest to designers considering the use of SCC in structural applications.Key words: self-consolidating concrete, shear resistance, shear resistance factor, aggregate interlock, dowel action.
27
Zanuy, Carlos, and Gonzalo S. D. Ulzurrun. "Impact Resisting Mechanisms of Shear-Critical Reinforced Concrete Beams Strengthened with High-Performance FRC." Applied Sciences 10, no. 9 (May 1, 2020): 3154. http://dx.doi.org/10.3390/app10093154.
Full textAbstract:
Reinforced concrete (RC) structures typically present brittle failures by shear or punching under impact loading. High-performance fiber-reinforced concrete (HPFRC) has great potential due to its superior strength and energy absorption. The higher price and environmental cost of HPFRC compared to conventional RC can be effectively overcome by partially strengthening impact-sensitive RC members with HPFRC. To study the feasibility of this technique, HPFRC was applied as a tensile layer at the bottom of RC beams. Drop weight impact tests were carried out on beams with two values (35 and 55 mm) of HPFRC thickness, in addition to companion RC beams. Results show that the impact response can be divided into two stages: a first stage governed by local effects and shear plug formation at midspan, and a second stage governed by global beam behavior with formation of shear web cracks. A new resisting mechanism was observed for beams strengthened with HPFRC, as the strengthening layer worked similarly to a stress ribbon retaining the damaged RC and reducing fragmentation-induced debris. Such mechanism was fully achieved by the specimens with 35 mm HPFRC layer but was limited for the specimens with 55 mm HPFRC layer due to impact-induced interface debonding.
28
Xia, Jun, Kevin R. Mackie, Muhammad A. Saleem, and Amir Mirmiran. "Shear failure analysis on ultra-high performance concrete beams reinforced with high strength steel." Engineering Structures 33, no. 12 (December 2011): 3597–609. http://dx.doi.org/10.1016/j.engstruct.2011.06.023.
Full text
29
Aghani, Kian, and Hassan Afshin. "Experimental and Numerical Investigation on Shear Retrofitting of RC Beams by Prefabricated UHPFRC Sheets." Civil Engineering Journal 2, no. 5 (May 30, 2016): 168–79. http://dx.doi.org/10.28991/cej-2016-00000023.
Full textAbstract:
Different methods are used for retrofitting RC members. One of the new methods in this field is using externally bonded fiber-reinforced Concrete (FRC) sheets in order to increase RC member’s shear and flexural strength. In this study, applicability of ultra-high performance fiber-reinforced concrete sheets in shear and flexural retrofitting of RC beams was investigated. In total, eight RC beams (dimensions 10×20×150 cm) with two different bending capacity and lack of shear strength were used and were tested in 3-points bending test. Of these, four were control beams and four were retrofitted with laterally bonded UHPFRC sheets. Dimensions of the sheets used for retrofitting were (3×15×126 cm). Also FEM analysis was used to model the effect of The method. the results show that this method can be well used for retrofitting RC beams. In this method the way of connecting sheets to beam’s surfaces has a fundamental role in behavior of retrofitted beams.
30
Li, Xiaoke, Changyong Li, Minglei Zhao, Hui Yang, and Siyi Zhou. "Testing and Prediction of Shear Performance for Steel Fiber Reinforced Expanded-Shale Lightweight Concrete Beams without Web Reinforcements." Materials 12, no. 10 (May 15, 2019): 1594. http://dx.doi.org/10.3390/ma12101594.
Full textAbstract:
In this paper, for a wide application of high-performance steel fiber reinforced expanded-shale lightweight concrete (SFRELC) in structures, the shear behavior of reinforced SFRELC beams without web reinforcements was experimentally investigated under a four-point bending test. Twenty-six beams were fabricated considering the influencing parameters of SFRELC strength, shear-span to depth ratio, longitudinal reinforcement ratio and the volume fraction of the steel fiber. The statistical analyses based on the foundational design principles and the experimental results are made based on the shear cracking resistance, the shear crack distribution and width, the mid-span deflection, the patterns of shear failure, and the shear capacity of the specimens. This confirms the effective strengthening of steel fibers on the shear performance of reinforced SFRELC beams without web reinforcements. Based on the modifications to the formulas of reinforced conventional concrete, lightweight-aggregate concrete or steel fiber reinforced concrete (SFRC) beams, and the validation against the experimental findings, formulas are proposed for the prediction of shear cracking resistance and shear capacity of reinforced SFRELC beams without web reinforcements. Finally, formulas are discussed for the reliable design of the shear capacity of reinforced SFRELC beams without web reinforcements.
31
Said, Asmaa, Mahmoud Elsayed, Ahmed Abd El-Azim, Fadi Althoey, and Bassam A. Tayeh. "Using ultra-high performance fiber reinforced concrete in improvement shear strength of reinforced concrete beams." Case Studies in Construction Materials 16 (June 2022): e01009. http://dx.doi.org/10.1016/j.cscm.2022.e01009.
Full text
32
Shan, Bo, Yan Xiao, Wei Liang Zhang, and Bo Liu. "Mechanical Performance of Connections for GluBam-Concrete Composite Beams." Applied Mechanics and Materials 847 (July 2016): 521–28. http://dx.doi.org/10.4028/www.scientific.net/amm.847.521.
Full textAbstract:
Selecting composite connections is a crucial factor for researching mechanical performance of GluBam-concrete composite structure (BCC). An initial stage of research on the feasibility of GluBam-concrete composite beams is described. Total three types of composite connector, six specimens in each type, have been conducted direct shear tests on small blocks. The shear-relative slip curves were measured and all the relevant mechanical properties such as slip moduli and shear capacities were calculated. According to the test results, all connectors can be classified into two types, which owned strong and stiff mechanical properties but low ductility, or less strength and stiffness but high ductility. The BCC systems presented own characteristics compared with the outcomes obtained from the TCC system. It was founded that some of connection systems were suitable for constructed GluBam-concrete composite structures. However only qualitative conclusions can be drawn at this stage and the performance of GluBam-concrete composite beams need to be investigated further.
33
Yang, Keun-Hyeok, and Ju-Hyun Mun. "Cyclic Flexural and Shear Performances of Beam Elements with Longitudinal Glass Fiber Reinforced Polymer (GFRP) Bars in Exterior Beam-Column Connections." Applied Sciences 8, no. 12 (November 22, 2018): 2353. http://dx.doi.org/10.3390/app8122353.
Full textAbstract:
The objective of this study is to examine the effect of the poor anchorage length of glass fiber reinforced polymer (GFRP) bars used for longitudinal reinforcement on the flexural and shear performances of beam elements in exterior beam–column connections made using high-strength materials. Six exterior beam–column connection specimens were tested under reversal cyclic loads applied at the free-end of the beam. The selected strength categories of materials in the beam element were as follows: 35 MPa and 70 MPa for the design compressive strength of concrete, 400 MPa and 600 MPa for the yield strength of conventional longitudinal steel bars, and 800 MPa for the tensile strength of the GFRP bar. All the longitudinal steel bars of the beams satisfied the minimum requirements of the provisions of ACI 318–14, whereas all the longitudinal GFRP bars of the beam were linearly anchored into the column section, resulting in poor anchorage length, especially for the beam with the concrete compressive strength of 35 MPa. The flexure-governed beams with GFRP bars exhibited a greater increasing rate in displacement at the pre-peak state and did not display the plastic flow characteristic after the peak load when compared with companion beams with steel bars. The beams with GFRP bars possessed lower diagonal cracking strengths and shear capacities than the companion beams with steel bars although the shear capacities of the beams with GFRP bars could be conservatively predicted using the design equation of ACI 440.1R–15 provision. The low elastic modulus and elongation capacity of GFRP bars resulted in large displacements and brittle post-peak beam performances. Furthermore, the lack of anchorage length of GFRP bars in exterior beam–column connection significantly reduced the flexural strength and ductility of the beam element.
34
Shatnawi, Amjed, Hana Mahmood Alkassar, Nadia Moneem Al-Abdaly, Emadaldeen A. Al-Hamdany, Luís Filipe Almeida Bernardo, and Hamza Imran. "Shear Strength Prediction of Slender Steel Fiber Reinforced Concrete Beams Using a Gradient Boosting Regression Tree Method." Buildings 12, no. 5 (April 25, 2022): 550. http://dx.doi.org/10.3390/buildings12050550.
Full textAbstract:
For the design or assessment of concrete structures that incorporate steel fiber in their elements, the accurate prediction of the shear strength of steel fiber reinforced concrete (SFRC) beams is critical. Unfortunately, traditional empirical methods are based on a small and limited dataset, and their abilities to accurately estimate the shear strength of SFRC beams are arguable. This drawback can be reduced by developing an accurate machine learning based model. The problem with using a high accuracy machine learning (ML) model is its interpretation since it works as a black-box model that is highly sophisticated for humans to comprehend directly. For this reason, Shapley additive explanations (SHAP), one of the methods used to open a black-box machine learning model, is combined with highly accurate machine learning techniques to build an explainable ML model to predict the shear strength of SFRC slender beams. For this, a database of 330 beams with varying design attributes and geometries was developed. The new gradient boosting regression tree (GBRT) machine learning model was compared statistically to experimental data and current shear design models to evaluate its performance. The proposed GBRT model gives predictions that are very similar to the experimentally observed shear strength and has a better and unbiased predictive performance in comparison to other existing developed models. The SHAP approach shows that the beam width and effective depth are the most important factors, followed by the concrete strength and the longitudinal reinforcement ratio. In addition, the outputs are also affected by the steel fiber factor and the shear-span to effective depth ratio. The fiber tensile strength and the aggregate size have the lowest effect, with only about 1% on average to change the predicted value of the shear strength. By building an accurate ML model and by opening its black-box, future researchers can focus on some attributes rather than others.
35
Shatnawi, Amjed, Hana Mahmood Alkassar, Nadia Moneem Al-Abdaly, Emadaldeen A. Al-Hamdany, Luís Filipe Almeida Bernardo, and Hamza Imran. "Shear Strength Prediction of Slender Steel Fiber Reinforced Concrete Beams Using a Gradient Boosting Regression Tree Method." Buildings 12, no. 5 (April 25, 2022): 550. http://dx.doi.org/10.3390/buildings12050550.
Full textAbstract:
For the design or assessment of concrete structures that incorporate steel fiber in their elements, the accurate prediction of the shear strength of steel fiber reinforced concrete (SFRC) beams is critical. Unfortunately, traditional empirical methods are based on a small and limited dataset, and their abilities to accurately estimate the shear strength of SFRC beams are arguable. This drawback can be reduced by developing an accurate machine learning based model. The problem with using a high accuracy machine learning (ML) model is its interpretation since it works as a black-box model that is highly sophisticated for humans to comprehend directly. For this reason, Shapley additive explanations (SHAP), one of the methods used to open a black-box machine learning model, is combined with highly accurate machine learning techniques to build an explainable ML model to predict the shear strength of SFRC slender beams. For this, a database of 330 beams with varying design attributes and geometries was developed. The new gradient boosting regression tree (GBRT) machine learning model was compared statistically to experimental data and current shear design models to evaluate its performance. The proposed GBRT model gives predictions that are very similar to the experimentally observed shear strength and has a better and unbiased predictive performance in comparison to other existing developed models. The SHAP approach shows that the beam width and effective depth are the most important factors, followed by the concrete strength and the longitudinal reinforcement ratio. In addition, the outputs are also affected by the steel fiber factor and the shear-span to effective depth ratio. The fiber tensile strength and the aggregate size have the lowest effect, with only about 1% on average to change the predicted value of the shear strength. By building an accurate ML model and by opening its black-box, future researchers can focus on some attributes rather than others.
36
Chakrawarthi, Vijayaprabha, Leon Raj Jesuarulraj, Siva Avudaiappan, Divya Rajendren, Mugahed Amran, Pablo Guindos, Krishanu Roy, Roman Fediuk, and Nikolai Ivanovich Vatin. "Effect of Design Parameters on the Flexural Strength of Reinforced Concrete Sandwich Beams." Crystals 12, no. 8 (July 22, 2022): 1021. http://dx.doi.org/10.3390/cryst12081021.
Full textAbstract:
Sandwich beams are preferable for aerostructure and marine structures due to their high mechanical strength, durability, stiffness, and fatigue resistance. This paper presents a study on the flexural behavior of sandwich beams made of self-compacting concrete comprising a polystyrene inner core with wire mesh reinforcement. The effect of the design parameters such as the inner core area, percentage of tension reinforcement, and wire mesh on the moment carrying capacity and failure modes of sandwich beams was analyzed. Ten beams were cast and tested to failure with simply supported end conditions and they were classified into three different groups. The longitudinal section of the inner core area was varied by 0% (control beam), 25%, 50%, and 75% of the gross area. The tension reinforcement ratio varied between 0.6 and 1.5%. In addition, the effect of the wire mesh in shear and flexural resistance was studied. The load-carrying capacity of sandwich beams increased with flexural reinforcement. In addition, the welded wire mesh improved the sandwich beams’ flexural and shear performance. The conventional expressions for the moment of resistance were valid for sandwich beams, whereas the shear strength expressions overestimated the capacity; therefore, modifications were suggested. The refined models had a significant agreement with the experimental results.
37
Smarzewski, Piotr, and Renata Spaczyńska. "Analysis of limit state of reinforced high performance hybrid fiber concrete deep beams with openings." Budownictwo i Architektura 10, no. 1 (June 11, 2012): 027–36. http://dx.doi.org/10.35784/bud-arch.2228.
Full textAbstract:
The article presents the analysis of the strength of reinforced deep beams with openings made of high performance hybrid fibre concrete – steel and polypropylene. We compared the results of the shear capacity of the analytically calculated values based on its own assessment of the theoretical capacity of the proposals deep beams members created by modifications of empirical formulas.
38
Albasyouni, Wahbi, and Mohamed Radwan. "Flexural Performance of Concrete Structures Reinforced with Fiber Reinforced Polymer (FRP)." iRASD Journal of Energy & Environment 3, no. 1 (June 29, 2022): 20–29. http://dx.doi.org/10.52131/jee.2022.0301.0022.
Full textAbstract:
ne of the most recent uses of FRP is to replace the use of steel in reinforced concrete structures. There are multiple reasons for deciding to choose FRP instead of steel such as their lightweight which can be quite beneficial to the design of buildings, high strength, and high flexibility. However, the initial use of this material was anticipated in the retrofitting of heritage buildings or any other damaged structures. There are several studies that concentrated on the use of FRP to enhance shear and flexural strength of concrete structures. However, limited studies concentrated on the effect of FRP on flexural behavior of concrete beams. Therefore, the aim of this research is to investigate the flexural performance of concrete beams that are reinforced using fiber reinforced polymers. The experimental program that was conducted in this study was divided into 4 different beams, 2 of them were reinforced using ordinary steel, while the other 2 were reinforced using carbon fiber reinforced polymer (CFRP). The highest potential deflection occurred in steel beam was 4.2 mm after applying a maximum of 42 MPa. The second beam was reinforced with FRP and accomplished 38.06 MPa, and the resulted deflection was around 12mm. The third beam was reinforced with steel and highest flexural strength measured was 75.56 MPa, while the deflection resulted from this load is 5.52 mm. Finally, the last beam was reinforced using FRP rebar and resulted deflection was 11.11 from 60.84 MPa. This study has showed the potential of using FRP in concrete structures especially in terms of flexural performance. Further studies are needed to investigate the influence of water and chemical substances on the performance of concrete beams reinforced with FRP.
39
Ni, Xiangyong, and Kangkang Duan. "Machine Learning-Based Models for Shear Strength Prediction of UHPFRC Beams." Mathematics 10, no. 16 (August 13, 2022): 2918. http://dx.doi.org/10.3390/math10162918.
Full textAbstract:
Estimating shear strength is a crucial aspect of beam design. The goal of this research is to develop a shear strength calculation technique for ultra-high performance fiber reinforced concrete (UHPFRC) beams. To begin, a shear test database of 200 UHPFRC beam specimens is established. Then, random forest (RF) is used to evaluate the importance of influence factors for the shear strength of UHPFRC beams. Subsequently, three machine learning (ML)-based models, including artificial neural network (ANN), support vector regression (SVR), and eXtreme-gradient boosting (XGBoost), are proposed to compute shear strength. Results demonstrate that the area of longitudinal reinforcement has the greatest influence on the shear capacity of UHPFRC beams, and ten parameters with high importance (e.g., the area of longitudinal reinforcement, the stirrup strength, the cross-section area, the shear span ratio, fiber volume fraction, etc.) are selected as input parameters. The models of ANN, SVR, and XGBoost have close accuracy, and their R2 are 0.8825, 0.9016, and 0.8839, respectively, which are much larger than those of existing theoretical models. In addition, the average ratios of prediction values of ANN, SVR, and XGBoost models to experimental results are 1.08, 1.02, and 1.10, respectively; the coefficients of variation are 0.28, 0.21, and 0.28, respectively. The SVR model has the best accuracy and reliability. The accuracy and reliability of ML-based models are much better than those of existing models for calculating the shear strength of UHPFRC beams.
40
Jung, Ju-Seong, Jae-Won Jeong, and Kang-Seok Lee. "Structural Performance Degradation of Corrosion-Damaged Reinforced Concrete Beams Based on Finite Element Analysis." Applied Sciences 12, no. 4 (February 17, 2022): 2090. http://dx.doi.org/10.3390/app12042090.
Full textAbstract:
The impact of the seismic performance of corrosion-damaged reinforced concrete (RC) members on the overall seismic performance of the entire RC structure must be investigated. Related research results provide important guidance for a more accurate seismic performance evaluation of RC structures with corroded members including beams and columns. However, currently available technologies for the seismic evaluation of existing RC structures do not consider the impact of reinforcement corrosion-induced deterioration on the seismic performance of RC members. The main focus of this study is on proposing a practical methodology to evaluate the seismic performance of such buildings. More specifically, the proposed methodology enables a direct quantitative evaluation of seismic performance by estimating the structural performance based on the strength and deformation capacity of corroded members. In pursuit of this research background and the objectives, our research team first performed an experimental study to estimate the impact of reinforcement corrosion on the structural behavior of RC shear beams and flexural beams and determine the factors associated with structural performance deterioration. A high correlation between the half-cell potential (HCP) before and after reinforcement corrosion of RC beams and the structural performance degradation factor based on the energy absorption capacity has been seen previously. In this study, a finite element analysis (FEA) was conducted, in which bond strength loss between rebar and concrete due to reinforcement corrosion of beam members was considered as one of the aging-related degradation factors, and the correlation between structural performance degradation before and after corrosion in beam members was studied. In addition, we compared and analyzed the results of the previous experimental research and FEA conducted in this study and proposed a structural performance degradation factor as a function of corrosion of shear and flexural beams. The research results indicate that the FEA-derived bonding factor (β) and performance degradation factor (ϕ) of flexural beam can be approximated with the equation ϕ=(0.36−β)−1+101 (R2 = 0.94), together with β–mV (average potential difference in voltage) correlation mV =(1.36−β)/(0.018−0.05β). In the case of shear beams, FEA resulted in ϕ=37.3β+63, which enables regression approximation, showing a high correlation (R2 = 0.98), together with β–mV correlation (mV =932.5β−1075). Using the mV–β–ϕ correlation curves, the bonding factor (β) depending on the degree of corrosion of RC beam members and the performance degradation factor (ϕ) based on the consequent strength-deformation capacity can be evaluated.
41
Liu, Zhengyu, Ali A. Semendary, and Brent M. Phares. "Numerical investigation on early age performance of ultra-high-performance concrete shear keys between an adjacent prestressed concrete box beams." Advances in Structural Engineering 25, no. 3 (December 7, 2021): 511–21. http://dx.doi.org/10.1177/13694332211056111.
Full textAbstract:
Adjacent precast prestressed concrete box beam bridges have been widely utilized for decades and have shown satisfactory performance. However, significant issues regarding to the longitudinal shear key cracking have been noted by bridge maintenance personnel. The cracks are typically initiated at beam-shear key interfaces due to shrinkage and temperature and propagate due to applied load. Recently, ultra-high-performance concrete (UHPC) was employed in the shear keys with the anticipation to prevent joint cracking. Although the field-collected data at early age from bridge utilizing UHPC shear keys indicated promising performance, the results only reflected the early age joint behavior at locations which were instrumented during the field test. In the current study, a 3D finite element (FE) model was developed to calculate the early age stresses due to shrinkage and temperature. The results indicated that the UHPC material associated with a specific shear key configuration created a “self-locked” phenomenon that generated compression on the upper level shear key. The early age tensile stress during the first couple of days near the end of the joint was relatively small compared to the tensile strength of UHPC material. Although the interface had sufficient capacity to resist the early age stresses, it is still a critical component and needs to be designed with sufficient capacity.
42
Wang, Wei, Xie-dong Zhang, Fa-xing Ding, and Xi-long Zhou. "Finite Element Analysis on Shear Behavior of High-Strength Bolted Connectors under Inverse Push-Off Loading." Energies 14, no. 2 (January 18, 2021): 479. http://dx.doi.org/10.3390/en14020479.
Full textAbstract:
High-strength bolted shear connectors (HSBSCs), which can be demounted easily and efficiently during deconstruction, are recommended to replace the conventional steel studs in steel–concrete composite beams (SCCBs) to meet the requirements of sustainable development. The existing investigations on the behavior of HSBSCs mainly focus on the positive moment area of composite beams, in which the concrete slab is in compress condition. In this paper, a three-dimensional finite element model (FEM) was developed to investigate the performance of HSBSCs subjected to inverse push-off loading. Material nonlinearities and the interactions among all components were included in the FEM. The accuracy and reliability of the proposed FEM were initially validated against the available push-off test results. Load-carrying capacity and load–slip response of the HSBSCs under inverse push-off loading were further studied by the verified FEM. A parametric study was carried out to determine the influence of the concrete strength, the diameter and tensile strength of bolt and the clearance between the concrete slab and the bolt as well as the bolt pretension on the shear performance of HSBSCs. Based on the extensive parametric analyses, design recommendations for estimating the shear load at the first slip and load-bearing resistance of HSBSCs were proposed and verified.
43
Harbi, Nibras Abbas, and Amer F. Izzet. "Performance of Post-Fire Composite Prestressed Concrete Beam Topped with Reinforced Concrete Flange." Civil Engineering Journal 4, no. 7 (July 30, 2018): 1595. http://dx.doi.org/10.28991/cej-0309198.
Full textAbstract:
The performance of composite prestressed concrete beam topped with reinforced concrete flange structures in fire depends upon several factors, including the change in properties of the two different materials due to fire exposure and temperature distribution within the composition of the composite members of the structure. The present experimental work included casting of 12 identical simply supported prestressed concrete beams grouped into 3 categories, depending on the strength of the top reinforced concrete deck slab (20, 30, and 40 MPa). They were connected together by using shear connector reinforcements. To simulate the real practical fire disasters, 3 composite prestressed concrete beams from each group were exposed to high temperature flame of 300, 500, and 700°C, and the remaining beams were left without burning as reference specimens. Then, the burned beams were cooled gradually by leaving them at an ambient lab condition, after which the specimens were loaded until failure to study the effect of temperature on the residual beams serviceability, to determine the ultimate load-carrying capacity of each specimen in comparison with unburned reference beam, and to find the limit of the temperature for a full composite section to remain composite. It was found that the exposure to fire temperature increased the camber of composite beam at all periods of the burning and cooling cycle as well as the residual camber, along with reduction in beam stiffness and the modulus of elasticity of concrete in addition to decrease in the load-carrying capacity.
44
Seckinli, Muhammed, and Musa Hakan Arslan. "Comparison of design and application criteria for various methods used in reinforced concrete beam strengthening." Global Journal of Arts Education 9, no. 1 (February 28, 2019): 35–42. http://dx.doi.org/10.18844/gjae.v9i2.4028.
Full textAbstract:
The design of the buildings to the earthquakes is a very critical issue. Some of existing reinforced concrete buildings does not have sufficient performance in terms of earthquake. These buildings must be demolished or strengthened. Strengthening design is not a simple engineering account but requires deep knowledge of composite material behavior. In this study, the structural advantages and disadvantages of various strengthening types of reinforced concrete beams are investigated. In this scope, reinforced concrete jacketing, strengthening with steel plate, strengthening methods with fiber polymers and external steel tie are investigated in detail. In the numerical part of the study, the effects of these methods are highlighted. In the analyzes, the reinforced concrete jacketing increased the bending and shear strength of the existing beam but the difficulty of this application was found to make it difficult for such designers to be preferred in beams. Also, the addition of new reinforced concrete section to be added to the lower zone of the beam has also contributed to the bending capacity by increasing the useful height of the beam. However, the strengthening with steel plate has a significant advantage in terms of bending capacity or shear and bending capacity and strengthening with fibrous polymer has significant benefit in shear capacity. It is also seen that carbon fiber polymer plates increase the bending strength as steel plates due to high tensile strength. The external wrapping is only useful in shear capacity of beam.
45
Aksoylu, Ceyhun, Yasin Onuralp Özkılıç, Marijana Hadzima-Nyarko, Ercan Işık, and Musa Hakan Arslan. "Investigation on Improvement in Shear Performance of Reinforced-Concrete Beams Produced with Recycled Steel Wires from Waste Tires." Sustainability 14, no. 20 (October 17, 2022): 13360. http://dx.doi.org/10.3390/su142013360.
Full textAbstract:
In parallel with the increase in vehicle sales worldwide, waste tires are becoming an increasing problem. The storage and disposal of these waste tires are critical environmental problems. Re-using these wastes in different areas instead of being disposed of is vital in preventing environmental pollution and creating new low-cost products. From this motivation, this paper investigates the properties of traditional reinforced-concrete beam with recycled steel wires (RSWT) obtained from the waste tires. RSWT were added to reinforced-concrete beam between 1% and 3% by weight with an increment of 1%. In total, 9 cubes, 12 cylinders and 12 reinforced-concrete beams were cast and tested to obtain the compressive, splitting tensile and flexural strengths, respectively. RSWT added to the concrete by 1%, 2% and 3% increased the compressive strength by 17.2%, 30.8% and 46.4%, respectively, compared to the reference concrete. In split tensile strength, 14.4%, 25.1% and 36.7% increases were observed, respectively. This showed that there was an effective increase in the compressive and tensile strength of concrete with the increase of fiber content. Although the effect of fiber content in samples with high stirrup spacing (27 cm) provides significant benefit in improving the beam behavior, the effect of fibers was more limited as the stirrup spacing decreased (20 cm and 16 cm). An approximation of over 91% was obtained between the analytical calculations and the experimental results. This shows that the analytical calculations given in the standards can be used for new experimental studies.
46
Kazemi, Mostafa, Mohammad Daneshfar, Yousef Zandi, Alireza Sadighi Agdas, Negin Yousefieh, Leili Mohammadifar, Aida Rahmani, et al. "Effects of the Concrete Strength and FRP Reinforcement Type on the Non-Linear Behavior of Concrete Deep Beams." Sustainability 14, no. 7 (March 30, 2022): 4136. http://dx.doi.org/10.3390/su14074136.
Full textAbstract:
To provide sustainable reinforced concrete deep beams, the replacement of steel rebars by FRP rebars with high-chemical resistance is proposed by researchers. However, the effects of the concrete strength, top and web longitudinal reinforcements, and types of FRP flexural rebars on the non-linear performance of concrete deep beams have rarely been evaluated. This study numerically assessed the effects of the top and web longitudinal reinforcements and concrete strength on the non-linear behaviour of GFRP- and CFRP-strengthened concrete deep beams with various shear span-to-overall depth (a/h) ratios. As per the results, the highest tensile stress was obtained for the steel reinforcement, and the tensile stress in the CFRP reinforcement was more than that of the GFRP reinforcement under the failure load. Meanwhile, the results of high- and normal-strength concrete deep beams with the web reinforcement (16.4%) were lower than those without the web reinforcement (22.3%). Therefore, the web reinforcement moderately compensated for the low strength of normal concrete and the absence of the top longitudinal rebar to reinforce concrete deep beams in carrying the ultimate load. Furthermore, the participation of the GFRP reinforcement with the high-strength concrete was more than that with the normal-strength concrete in carrying a higher amount of loading.
47
Wani, Shoib Bashir, Sarvat Gull, Ishfaq Amin, and Ayaz Mohmood. "Analytical and experimental study on shear performance of RCC beam elements reinforced with PSWC rebars: a comparative study." Challenge Journal of Concrete Research Letters 11, no. 3 (September 8, 2020): 53. http://dx.doi.org/10.20528/cjcrl.2020.03.002.
Full textAbstract:
Early distress in RCC (Reinforced Cement Concrete) structures in the recent times poses a major problem for the construction industry. It is found that in most of cases, distresses in reinforced concrete structures are caused by corrosion of rebar embedded in the concrete. The HYSD (High Yield Strength Deformed) rebars which are used to offer excellent strength properties is detrimental to durability due to action of ribs as stress concentrators. Nowadays, concept of PSWC rebars (plain surface with wave type configuration rebars, formerly known as C-bars/mild steel rebar with curvy profile) is emerging to have a compromise between strength and durability. This investigation assesses the flexural behaviour of RCC elements reinforced with PSWC rebars. The flexural performance of RC beams of size 1000mm x 150mm x 150mm reinforced with PSWC rebars at 4mm and 6mm deformation level was studied by conducting test as per IS 516-1959 under four point loading. The performance of PSWC bar reinforced elements are compared with beams reinforced with mild steel rebars, HYSD rebars with spiral and diamond rib configuration to assess the viability of PSWC rebars to replace conventional reinforcement. The test results are validated by numerical analysis with the help of ANSYS software. Totally 15 beams are subjected to flexure test and the performance evaluators are first crack load, deflection at first crack load, ultimate load carrying capacity, deflection at ultimate load, load-deflection behaviour, load-strain behaviour and failure pattern. It is found that PSWC rebars as reinforcement in concrete beams enhanced the ductile behaviour of beams as compared to conventional HYSD and mild steel rebar beams. The energy absorbing capacity has increased significantly for beams reinforced with PSWC rebars when compared with conventional HYSD and mild steel rebar beams. The load-deflection behaviour and failure mode of PSWC rebars reinforced concrete beams were found to be similar to that of high yield strength rebars irrespective of deformation level. The analytical investigation from ANSYS software gave good agreement with the experimental results. It is concluded that PSWC bar has the potential to replace conventional HYSD rebar. Further study needs to be done to optimize the profile level and stirrup locations; and usage with high concrete grade for effective exploitation.
48
Xiao, Tong-Liang, Hong-Xing Qiu, and Jia-Le Li. "Seismic Behaviors of Concrete Beams Reinforced with Steel-FRP Composite Bars under Quasi-Static Loading." Applied Sciences 8, no. 10 (October 14, 2018): 1913. http://dx.doi.org/10.3390/app8101913.
Full textAbstract:
Steel-fiber reinforced polymer (FRP) composite bar (SFCB) is a new composite material with good corrosion resistance and designable post-yield stiffness. Substitution of steel bar with SFCB can greatly increase the durability and ultimate capacity associated with seismic performance. First, the method and main results of the experiment are briefly introduced, then a simplified constitutive model of composite bar material was applied to simulate the seismic behaviors of the concrete beams reinforced with SFCBs by fiber element modeling. The simulation results were found to be in good agreement with test results, indicating that the finite element model is reasonable and accurate in simulating the seismic behaviors of beams reinforced with SFCB. Based on the numerical simulation method, a parametric study was then conducted. The main variable parameters were the FRP type in composite bars (i.e., basalt, carbon FRP and E-glass FRP), the concrete strength, basalt FRP (BFRP) content in SFCBs and shear span ratio. Seismic behaviors such as load-displacement pushover curves, seismic ultimate capacity and its corresponding drift ratio of the SFCBs reinforced concrete beams were also evaluated. The results showed that (1) the fiber type of the composite bar had a great impact on the mechanical properties of the beam, among which the beam reinforced with BFRP composite bar has higher seismic ultimate capacity and better ductility. With the increase of the fiber bundle in the composite bar, the post-yield stiffness and ultimate capacity of the component increase and the ductility is better; (2) at the pre-yield stage, concrete strength has little influence on the seismic performance of concrete beams while after yielding, the seismic ultimate capacity and post-yielding stiffness of specimens increased slowly with the increase in concrete strength, however, the ductility was reduced accordingly; (3) as the shear span ratio of beams increased from 3.5 to 5.5, the seismic ultimate capacity decreased gradually while the ultimate drift ratio increased by more than 50%. Through judicious setting of the fiber content and shear span ratio of the composite bar reinforced concrete beam, concrete beams reinforced with composite bars can have good ductility while maintaining high seismic ultimate capacity.
49
Jang, Seok-Joon, Dae-Hyun Kang, Kyung-Lim Ahn, Wan-Shin Park, Sun-Woong Kim, and Hyun-Do Yun. "Feasibility of Using High-Performance Steel Fibre Reinforced Concrete for Simplifying Reinforcement Details of Critical Members." International Journal of Polymer Science 2015 (2015): 1–12. http://dx.doi.org/10.1155/2015/850562.
Full textAbstract:
This paper addresses the effects of hooked-end steel fibre contents on the mechanical properties of high-performance concrete (HPC) and investigates the feasibility of utilizing steel fibres to simplify the complicated reinforcement detailing of critical HPC members under high shear stress. Mechanical properties of HPCs with specified compressive strength of 60 and 100 MPa include the flow, air content, compressive strength, and flexural strength. The effectiveness of 1.50% steel fibre content on the shear behaviour of diagonally reinforced concrete coupling beam without additional transverse reinforcement was investigated to alleviate complex reinforcing details for the full section confinement of diagonal bar groups. The test results revealed the incorporation of steel fibres significantly affected the mechanical properties of the HPCs. For diagonally reinforced coupling beam (SFRCCB) without additional transverse reinforcement, the addition of 1.5% steel fibre content into 60 MPa HPC coupling beam provides similar cracking and structural behaviours compared to those of diagonally reinforced coupling beam (CCB) with full section confinement details. However, the ductility of SFRCCB was less than that of CCB. It is recommended that both stirrups and steel fibre should be used for fully confining the diagonal bar groups of coupling beams to achieve the ductile behaviour.
50
Smarzewski, Piotr. "Hybrid Fibres as Shear Reinforcement in High-Performance Concrete Beams with and without Openings." Applied Sciences 8, no. 11 (October 26, 2018): 2070. http://dx.doi.org/10.3390/app8112070.
Full textAbstract:
The article presents the results of research work aimed at testing the use of hybrid steel-polypropylene fibre as a strengthening solution to upgrade reinforced high-performance concrete (HPC) beams with openings (BO1 ÷ BO3) and without (B1 ÷ B3). A total of six simply supported beams were tested under four-point bending. The test beams had a cross section of 200 × 400 mm and a total length of 2500 mm. Two square openings in each shear span were located symmetrically about the mid-point in three BO beams. Research was carried out with regard to the quantity and type of reinforcement. Beams B1 and BO1 were constructed with traditional reinforcement made of steel bars. As regards the remaining beams, instead of stirrups and compressive bars, fibre reinforcement of varying fibre volume contents was applied. In the analysis, a non-contact system for three-dimensional measurements of strain and displacement was used. Analysis of the behaviour of the beams under static load was based on the measurements of cracks, deflections and strains. The test results show that the first diagonal crack and the ultimate shear strength increase significantly as the fibre content increases. The above study showed that the hybrid fibres have a positive effect, reducing crack width and ensuring an increase in the load-bearing capacity.