scholarly journals Ductility Improvement of R.C Beams with Large Web opening by using Reactive Powder Concrete Layers

2018 ◽  
Vol 25 (3) ◽  
pp. 30-39
Author(s):  
Husain Khalaf Jarallah ◽  
Nidaa Qassim Jassim
Keyword(s):  
Ultimate Load ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Reactive Powder Concrete ◽  
Normal Concrete ◽  
Simply Supported ◽  
Hybrid Beam ◽  
Web Opening ◽  
Hybrid Beams ◽  
Reactive Powder

In this investigation the effect of large web opening on the on the behaver of beams made by normal concrete (NC) and reactive powder concrete (RPC) have been studied. The experimental work consists of casting and testing in flexure 12 rectangular simply supported reinforced concrete beams. The main parameters of this test are opening locations and normal concrete and RPC location with is the section. The ultimate loads, cracking loads, load -deflection behavior, skew of the openings (deflection at the two opposite corners of openings) and ductility were discussed. These results showed that increase ultimate loads (Pu) and stiffness by increase RPC layers. The using RPC layers increase ultimate load about (1-30) %. Using RPC in compression fiber is found to be more effective than using RPC in tension fiber. The cracking load of hybrid beam with one layer of RPC in compression fiber (having one opening) higher than NC beams by 48.5%. The ultimate strength was decreases with increases opening about (4-21)%, thus indicating that the stiffness decreases accordingly. Hybrid beams with RPC in tension fiber failed with less crack than those for hybrid beams with RPC in compression fiber at the same number of openings. The skew at opening of flexural zone show greater values than the skew at opening in shear zone for each beam until failure. The increase in the number of openings leads to increase in the ductility because it reduces the strength of beams.

The Influence of Shear Strain on the Torsion Capacity of Hybrid Beams

2020 ◽  
Vol 38 (7A) ◽  
pp. 951-959
Author(s):  
Alyaa H. Mohammed ◽  
Kaiss F. Sarsam ◽  
Qais A. Hasan
Keyword(s):  
Shear Strain ◽  
Concrete Beams ◽  
Side Surface ◽  
Reinforced Concrete Beams ◽  
Strain Gauges ◽  
Conventional Concrete ◽  
Hybrid Beam ◽  
Strength Tests ◽  
Hybrid Beams ◽  
Reactive Powder

This research discusses experimentally the shear strain of the reinforcement concrete hybrid beams composed of reactive powder concrete (RPC) at the peripheral and conventional concrete (CC) at the core beams under torsional strength tests. Shear strain is usually represented by (), which is explained as the tangent of the angle and is be like the length of deformation at its maximum divided by the length of perpendicular in the plane of the force application. Twelve reinforced concrete beams are tested having the following dimensions: 100, 200 and 1500mm as width, height and length respectively with thickness of the RPC concrete were 40 and 20mm. The beams were cast and tested to failure in torsion by using two opposite cantilevers steel arms that contribute to transferring the torque to the centre of the beams. Two control (CC and RPC) beams were poured, and the ten other beams were all poured as hybrid ones. Experimental data of the three strain gauges locations in the middle of the beams in one of the side surface face, to calculate shear strain (). The percentage of shear strain at ultimate torsion capacity was reduced by about 76% for RPC (RP) to CC (NC) beams and 63% for hybrid beam (H1) to CC (NC) beam.

FLEXURAL BEHAVIOR OF STRENGTHENED AND RPIARED SUSTAINABLE R.C. BEAMS USING REACTIVE POWDER CONCRETE JACKET

2021 ◽  
Vol 25 (Special) ◽  
pp. 4-44-4-56
Author(s):  
Mohammed S. Zimmawe ◽  
◽  
Nagham T. Hamad ◽  
Keyword(s):  
Reinforced Concrete ◽  
Ultimate Load ◽  
Coarse Aggregate ◽  
Concrete Beams ◽  
Load Capacity ◽  
Reinforced Concrete Beams ◽  
Flexural Behavior ◽  
Reactive Powder Concrete ◽  
Limit Condition ◽  
Reactive Powder

Thin fiber reinforcement and rehabilitation of reinforced concrete beams Concrete jackets have several benefits, including increased ultimate load and improved serviceability limit condition. The current paper was carried out to investigate the effect of the strengthening and repairing by using reactive powder concrete(RPC) jacket for reinforced concrete beams that’s casted with recycled coarse aggregate (RCA) in enhancement the mechanical properties such as load capacity and deflection . Nine reinforced concrete beams mm were casted by using RCA with constant details and jacketed with RPC with variable of steel fiber content and jacket thickness to estimate the optimum details. The result showed the effectiveness of the proposed technique in both deflection and ultimate load.

scholarly journals Flexural Behavior of Rubberized Reinforced Concrete Beams

2018 ◽  
Vol 7 (4.20) ◽  
pp. 316 ◽  
Author(s):  
Adel A. Al-Azzawi ◽  
Dalia Shakir ◽  
Noora Saad
Keyword(s):  
Ultimate Load ◽  
Coarse Aggregate ◽  
Concrete Beams ◽  
Fiber Content ◽  
Reinforced Concrete Beams ◽  
Flexural Behavior ◽  
Rubberized Concrete ◽  
Normal Concrete ◽  
Rubber Material ◽  
Rubber Waste

In Iraq, the use of rubber waste material in concrete is an interesting topic due to its availability in large volumes. Researches of applications of rubber waste in concrete have been increased since 2003. Many studies carried out to investigate the performance of concrete using different ratios of rubber as a replacement to fine or coarse aggregate. In this research, rubber wastes from scrapped tires have been added as fiber to concrete mix with presence of 0.5% superplasticizer. The flexural behavior of concrete beams, mechanical properties of concrete and workability of concrete mixes have been studied. Rubber fibers ranging from (2-4) mm were added in percentages of 0.5% and 1%) of the cement weight. The results have demonstrated that the addition of rubber material as fibers in natural aggregate concrete enhances its ductility, compressive strength and tensile strength compared to the normal concrete. The effect of rubber fiber content is found to be significant on the behavior of tested beams. If the fiber content increased from 0 to 0.5% the cracking load increased by 60 % and ultimate load increased by 21%. For rubberized concrete, if the fiber content increased from 0.5 to 1.0%, the cracking load decreased 7% and ultimate load increased by 4%.   

Performance of Reinforced Concrete Beams with Multiple Openings

2020 ◽  
Vol 857 ◽  
pp. 162-168
Author(s):  
Haidar Abdul Wahid Khalaf ◽  
Amer Farouk Izzet
Keyword(s):  
Reinforced Concrete ◽  
Ultimate Load ◽  
Concrete Beams ◽  
Load Capacity ◽  
Reinforced Concrete Beams ◽  
Design Parameters ◽  
Ultimate Load Capacity ◽  
Concentrated Load ◽  
Simply Supported ◽  
Group I

The present investigation focuses on the response of simply supported reinforced concrete rectangular-section beams with multiple openings of different sizes, numbers, and geometrical configurations. The advantages of the reinforcement concrete beams with multiple opening are mainly, practical benefit including decreasing the floor heights due to passage of the utilities through the beam rather than the passage beneath it, and constructional benefit that includes the reduction of the self-weight of structure resulting due to the reduction of the dead load that achieves economic design. To optimize beam self-weight with its ultimate resistance capacity, ten reinforced concrete beams having a length, width, and depth of 2700, 100, and 400 mm, respectively were fabricated and tested as simply supported beams under one incremental concentrated load at mid-span until failure. The design parameters were the configuration and size of openings. Three main groups categorized experimental beams comprise the same area of openings and steel reinforcement details but differ in configurations. Three different shapes of openings were considered, mainly, rectangular, parallelogram, and circular. The experimental results indicate that, the beams with circular openings more efficient than the other configurations in ultimate load capacity and beams stiffness whereas, the beams with parallelogram openings were better than the beams with rectangular openings. Commonly, it was observed that the reduction in ultimate load capacity, for beams of group I, II, and III compared to the reference solid beam ranged between (75 to 93%), (65 to 93%), and (70 to 79%) respectively.

scholarly journals Structural Behavior of Continuous Steel-Reactive Powder Concrete Composiate Beams Under Repeated Loads

2018 ◽  
Vol 7 (4.19) ◽  
pp. 843
Author(s):  
Rasha Yassien Dakhil ◽  
Mustafa B. Dawood
Keyword(s):  
Ultimate Load ◽  
Concrete Beams ◽  
Numerical Models ◽  
Experimental Tests ◽  
Reactive Powder Concrete ◽  
Mode Of Failure ◽  
Reactive Powder ◽  
And Behavior ◽  
Push Out ◽  
Repeated Loads

A study for the continuous composite steel-reactive powder concrete beams under repeated loads were executed experimentally and analytically. In the experimental part, six continuous composite sections were constructed as test beams. "The‘“decks slab concretes"was connected tos steel I-beams by headed steel studs welded to the top flanges“ofs“thes‘‘steel I-beams.“T,he dimensions“ of “the“ deck slab is (2200×250×80mm), while the type of I-beam is (IPE 140) with length of (2200mm). For the present work, the experimental work includes also examining the shear in the links by creating two models (push out) and tested to determine the properties and behavior of the studs. The behavior of the studs were conducted by"getting load-slip curves. In the part of the,oretical,‘‘.tested beams.was numericallysmodeled then analyzed using thesfinite element method.‘“Thes“numerical models were carried out in three dimensionss bys“the software package (ANSYS 16.1). Verifi,cationsof thesnumericalsresults“was donesbyscompari,ngs thems with the experimentals results. “Thesresultssof thesfiniteselementsanalysissshowed good agreements‘with the results ofsthe experimental tests. The maximumsandsminimum difference‘‘in ultimate loa,ds for beams‘‘ were (5.85% and 1.33%) respectively.  The results show that stiffenerssof beamssandsstrengthening with CFRP shall increase the ultimate load capacity‘and affects on‘‘mode of failure“ of theses beams.‘  

scholarly journals Experimental Research on Concrete Beams Reinforced with High Ductility Steel Bars and Strengthened with a Reactive Powder Concrete Layer in the Compression Zone

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4173 ◽  
Author(s):  
Zbigniew Perkowski ◽  
Mariusz Czabak ◽  
Stefania Grzeszczyk ◽  
Daniel Frączek ◽  
Karolina Tatara ◽  
...  
Keyword(s):  
Cross Sections ◽  
Concrete Beams ◽  
Reference Beam ◽  
Maximum Load ◽  
Concrete Cover ◽  
Reinforced Concrete Beams ◽  
Reactive Powder Concrete ◽  
High Ductility ◽  
Compression Zone ◽  
Reactive Powder

The article describes four-point bending tests of three reinforced concrete beams with identical cross-sections, spans, and high-ductility steel reinforcement systems. Two beams were strengthened in the compressed section with a thin layer of reactive powder concrete (RPC) bonded with evenly spaced stirrups. Their remaining sections, and the third reference beam, were made of ordinary concrete. Measurements of their deflections, strains and axis curvature; ultrasonic tests; and a photogrammetric analysis of the beams are the main results of the study. For one of the beams with the RPC, the load was increased in one stage. For the two remaining beams, the load was applied in four stages, increasing the maximum load from stage to stage in order to allow the analysis of the damage evolution before reaching the bending resistance. The most important effect observed was the stable behaviour of the strengthened beams in the post-critical state, as opposed to the reference beam, which had about two to three times less energy-absorbing capacity in this range. Moreover, thanks to the use of the RPC layer, the process of concrete cover delamination in the compression zone was significantly reduced, the high ductility of the rebars was fully utilized during the formation of plastic hinges, and the bending capacity was increased by approximately 12%.

scholarly journals Flexural Behavior of Reactive Powder Concrete with Hybrid Section T- Beams

2021 ◽  
Author(s):  
Rafid Saeed Atea
Keyword(s):  
Silica Fume ◽  
Flexural Behavior ◽  
Experimental Program ◽  
Reactive Powder Concrete ◽  
Normal Concrete ◽  
Hybrid Beams ◽  
Hybrid Section ◽  
Current Duration ◽  
Reactive Powder ◽  
T Beam

Abstract Reactive powder concrete (RPC) is unique of the present and greatest significant improvements in constructions field, it has usual excessive kindness happening current duration in the world owing toward its higher concrete properties, great ductility, durability, shrinkage, great opposition to corrosion and abrasion. In this experimental investigation is carried out on the way to revision the RPC flexural activity with Hybrid Segment T- Beams and the mechanical characteristics of this building material. In order to analyze the belongings of steel fiber volumetric ratio, silica fume ratio, tensile steel ratio, hybrid section on RPC T-beam flexural efficiency, the experimental program included testing five beams. The study was focused on determining the load-deflection behavior, letdown mode, strain supply across the depth of the beams and crack pattern at failure. The results of the volumetric ratio of steel fibers and the silica fume ratio were also considered in studying the mechanical properties of RPC mixes. Moreover, a study of hybrid beams showed that use of RPC web and normal concrete in flange efficiently improves the performance of T-beams compared to normal concrete T-beams with a percentage rise of 12 percent and hybrid beams have also shown that the use of RPC flange and normal concrete in web efficiently improves the display of T-beams associated to regular concrete T-beams with percentages increase of 28%.

scholarly journals Behavior and strength of reinforced reactive powder concrete beams under impact loadings

2018 ◽  
Vol 7 (4) ◽  
pp. 2753
Author(s):  
Ibtihal Fadhil ◽  
Ayad K. Kadhem ◽  
Nisreen Salih
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Steel Fiber ◽  
Concrete Beams ◽  
Impact Load ◽  
Experimental Tests ◽  
Reinforced Concrete Beams ◽  
Reactive Powder Concrete ◽  
Reactive Powder ◽  
The Impact

Reactive powder concrete is a new concrete that has been used in recent years because of many advantages. The use of reactive powder concrete in structural elements such as beams provides higher compressive strength, higher modulus of elasticity, durable concrete and increasing the concrete ductility, so that the concrete has high resistance against tensile stress. The experimental tests of the reinforced concrete beams under the effects of impact loadings are investigated in this paper. The parameters being adopted in present paper are steel fiber of (1, 1.5 and 2%) by volume, dropped mass and height of drop. The reinforced concrete specimens were tested under impact load by one strike only. The test results indicate that the impact force increased when the compressive strength of concrete increased that when the steel fiber ratio becomes more and the deflection has become less.  

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