Tensile and bond stresses were measured along reinforcing bars by a new technique which does not disturb bond stresses. In the case of cold worked deformed bars, heating causes the reinforcement to revert to mild steel as it loses the effects of strain hardening. Eleven standard sizes of reinforcing bars are in userebar could be procured locally and could be metric. Tensile testing on steel reinforcing bar rebars astm a370. Thus, the need for testing reinforcing bars so as to obtain information on their. Three tensile tests for each type of steel reinforcement were executed on specimens of adequate length 600 mm. Attributes of ductile reinforcing steel pdf extracts. A drawback of the majority of the research is that gfrp. Oct 29, 2018 tensile test is the most common test performed on a reinforced steel bar. Remember, the reason for using reinforcing steel in concrete is to increase the tensile strength of concrete, since concretes strength is primarily compressive strength. Tensile behaviour was investigated for reinforcing steel bars used in the. In fact, the most common test for steel bar reinforcement is the tensile test, bending test and chemical analysis.
Astm a370 tensile testing and bend testing steel reinforcing. These standards include testing requirement that are specific to determining rebar tensile and bend properties. Tensile strength properties of steel, bamboo and rattan bars the physical and tensile strength properties of steel, bamboo and rattan were determined experimentally using a 600 kn capacity averydenison servohydraulic universal testing machine utm shown in figure 1. Reinforcing bars in concrete elements functions as the component carrying tensile stresses after concretecracking. Show below hide below 1 as 21991 steel reinforcing bars for concrete 4 preface 5. Tensile tests of these steel samples were conducted under. The bars vary in designation from with additional bars. Length 9m, 10m, 11m, 12m and m, or can be supplied as special lengths as per customers requirements, not exceeding m. The main reinforcing in this situation would be the lowest layer of reinforcin g bars. You can also choose from aisi, jis, and astm tensile strength of reinforcing steel bars there are 108 suppliers who sells tensile strength of reinforcing steel bars on, mainly located in asia. For class 1 and class 2 steel reinforcing bars, purchasers testing includes determination of mass per metre, tensile test and rebend test. This fsel test standard is used to determine the tensile properties of reinforcing bars.
Machines and tensile grips for tensile testing of steel reinforcing bars must be capable of applying very high loads. Flexure tests on reinforcing steel are used to test ductility. Class 3 steel reinforcing bars is rarely used nowadays in hong kong, deletion of class 3 steel reinforcing bars will not adversely affect the supply of steel reinforcement bars for use in hong kong. When the section is loaded as shown in figure 2, the section flexes downward. In the work of kareem 2006 sample used was limited to one and only mechanical test of tensile strength was done.
From knowledge of the specimen geometry we can calculate the engineering stress and strain from the load vs. The tmt rebar is strained by the tensile force an elongated, generally to the point of failure, for the purpose of determining tensile strength. Test setup and results university of stuttgart gerster 1989 nagatomo and kaku nagatomo 1990, 1992 investigated the bond behaviour of ribbed reinforcing bars d s 22 mm depending on the transverse tension level and the concrete cover, using pullout tests with an embedment length of l b 7d s. Table 71 lists the bar number, area in square table 73 is given for comparison. Highstrength reinforcing bars introduction grade 60 reinforcing steel, with a yield strength of 60,000 psi, is the most commonly used grade in north america. Appendix 9 to astm a370 specifically addresses tensile testing or reinforcing bars. Curves for representative beam and pullout specimens show tensile force distribution, bond stress distribution, applied moment versus measured bar tension, comparison of beam and pullout tensile force distribution, and. Reinforcing bars are used in reinforced concrete and are one of the main parts of r. Nos of rebar sample 4, length of rebar sample about 500 mm. This is to avoid the use of steel reinforcing bars from a non quality assured source 2. A tensile test machine able to apply a tensile force greater than the ultimate tensile strength of the sample. A tension test of materials is a destructive process that provides information about the tensile strength, yield strength and the elasticity of the sample.
This test is done to determine how the material reacts when you apply force on it. Coupler mechanical device that physically connects two reinforcing bars. Steel reinforcing bar or rebar tensile test machines. However, ogunbiyi et al 2015 reported the tensile strength of bamboo in the southwestern nigeria, about 94 mpa. The rate at which a test is performed can have a significant effect on tensile properties. The meanings of batch of steel reinforcing bars for manufacturers testing and for purchasers testing. The testing procedure was repeated for the rest of the specimens. Steel reinforcement bar rebar a tensile testing guide. Many of these rebar standards also make reference to the widely recognized metals tensile testing standards, such as astm e8, iso 68921, en 21, as 91, jis z 2241, gbt 228. Tensile and chemical analyses of selected steel bars. The most important test is the tensile strength test. Materials that are sensitive to strain rates exhibit higher tensile strengths and lower elongations at faster speeds. The various test methods described in this standard are applicable to any type of mechanical splice manufactured to join steel reinforcing bars of any grade, uncoated or coated. Tensile reinforcement an overview sciencedirect topics.
The astm e290 mandated that bars have to pass the bending test, whereas reinforcing steel bars arebend to almost 1800 to ensure. These bars are produced in sections from 6 mm to 50 mm dia. Typically, three samples are tested for each bar size used in the test program. Pdf reinforcing bars in concrete elements functions as the component carrying tensile stresses after concretecracking. This process will result in a loading and reloading of steel. Tensile testing and bend testing steel reinforcing bar to. How to perform astm a1034 mechanical splice of steel bars. Steel reinforcing bars for the reinforcement of concrete. Carbon steel bars for the reinforcement of concrete cedd. For that reason, quality of plain and deformed bars should be checked specially for yield, ultimate strength and elongation ductility. Identify the reinforcing bars to be tested and cut them to a length of approximately 30 in.
The variability of the mechanical properties and weight of steel reinforcing bars produced in the united states and canada under astm a 615, a 616, and a 706 in 1997 is evaluated and expressions are developed to represent the probability distribution functions for yield and tensile strength. Mpa, yet, the only reinforcing bars consumed in the country is steel. Concrete reinforcing steel institute crsi manual of standard practice c. Tensile testing was carried out on the supplied material in the as rolled.
This is due to that fact that concrete exhibit very high compression strength. The nominal mass of an individual sample shall be calculated by determining the mass of any. Maybe, you are not too familiar with chemical analysis. Bond behaviour between reinforcing steel and concrete. A typical sn diagram obtained for the ultimate bond strength between reinforcement and concrete. Pdf comparative analysis of the tensile strength of bamboo. A slipmeasuring device consisting of two calibrated dial indicators that. Standard specification for deformed and plain carbonsteel. Use of steel reinforcing bars with higher tensile strength calls for corresponding increase in bond capacity. The standard covers tension, compression, cyclic load, highcycle fatigue, and slip tests. The tmt process is a revolutionary process as it provides the steel bars high tensile strength as well as ductility. Rp486 theareasandtensilepropertiesofdeformed concretereinforcementbars bya.
Testresources offers the test machines and fixtures required to perform tensile tests on rebar. Reinforcing bars often need bending fabrication into various shapes to accommodate the stresses in the projects design. Tensile specimens and test machines stressstrain curves, including discussionsof elastic versus plastic deformation, yield points, and ductility true stress and strain test methodology and data analysis it should be noted that subsequent chapters contain more detailed information on these topics. The preprogrammed test procedure should be adequate for most rebar testing. The american concrete institute aci recognized this and places a reduction factor on the allowable design strength of gfrp reinforcing bars. The tensile test is method to measure the mechanical properties of materials. I wasnt aware that there are so many test conducted on steel bars. Tensile lap splicing of frp reinforcing bars in concrete. In atc 115 atc 2014, highstrength reinforcing bars hsrb were considered any.
Pdf comparative analysis of the tensile strength of. The tensile properties is higher compared to other rebars. Chapter 3 fabrication and placement of reinforcing steel. The specimen must not lose strength and no cracks must be detected on visual inspection. Statistical analysis of reinforcing steel properties core. From a tension test, a variety of data are acquired that are needed for design purposes. The welding of reinforcement is generally not permitted for high tensile steel as heating hot rolled bars causes brittle fracturing of the reinforcement. Comparative studies of steel, bamboo and rattan as. Mild steel can be supplied as standard lengths for all diameters. Notice that these reinforcing bars run from one support to the other. It relates the effect of a uniaxial tensile load force on the elongation change in length of a standard specimen.
In addition, chemical analysis and determination of bond property are also required to be carried out by the purchasers. The areas and tensile properties of deformed concrete. During this stretching, the reinforcing steel elongates and retains its tensile strength. As 21991 steel reinforcing bars for concrete sai global. The beams were reinforced with spliced carbon or glass frp bars. Anchorage of epoxycoated rebar using chemical adhesives. Bond behaviour between reinforcing steel and concrete under. In contrast to the lower grades, which have ratios of specified tensile strength to specified yield strength that range from 1. Mechanical performance of steel reinforcing bars in uncorroded and. Testing the tensile strength of rebar on the riehle universal machine in our ontario, california laboratory. Measurement of the distribution of tensile and bond stresses. A wide variety of tensile strength of reinforcing steel bars options are available to you, such as electronic, hydraulic.
Tensile testing on steel reinforcing bar rebars astm. Length 12m and m, or can be supplied as special lengths as per customers requirements, not exceeding m. This document will focus primarily on the very common, yet sometimes challenging, tensile test. Astm a370, iso 10180, iso 15630, din 488, jis g3112 reinforced steel and ribbed reinforcement bars are essential for civil engineering. Pdf steel reinforcement bar rebar a tensile testing. A typical instron load frame used for tensile testing. Rebar we supply rebar of standard diameters and lengths. This machine must be accurate and calibrated in accordance with astm a 370.
In this study a complete tensile test analysis was done from three randomly selected steel bar samples each designated as st 442 and st662. Mechanical coupler testing report for barsplice products. Materialrelated factors that influence the tensile response of bars and should therefore be reported include the following. Note that test values of es may be of the order of 26,000,000 to. The pre programmed test procedure should be adequate for most re inforcing bar testing. Tensile properties for plastics, polymers and steels are very sensitive to testing rates, but aluminum alloys exhibit little sensitivity. Pocketsized card is a handy reference showing standard bar sizes, diameters, areas and weights along with hook details. Standard test method for tensile properties of fiber. The number of samples is to be determined by the research team. Since concrete has a high compressive strength but a lower tensile strength, it is reinforced with the incorporated steel. Also shows minimum yield and minimum tensile requirements per astm. Recent advances have enabled reinforcing steels of higher strengths to be commercially produced. The effects of the bar diameter and splice length on the bond strength are investigated. Reinforcing bars rebars these bars are readily available in straight length of 60 ft.
The testing is in general conformance with astm a37015 standard test methods and definition for mechanical testing of steel products and astm a61516 standard specification for deformed and plain carbonsteel bars for concrete reinforcement. Steel reinforcement bar rebar a tensile testing guide instron. Tensile strengthyield strength tsys ratios of highstrength steel. Steel reinforcement bar rebar a tensile testing guide introduction steel reinforcing bar, or rebar, is embedded in concrete to improve the overall strength of the concrete that surrounds it. For all tests, the strain average was measured over a 20 bar diameter gage length that included the connector and portions of the two reinforcing bars being coupled. Chapter 11 standard test procedures steel reinforcement tests may 2001 page 11. Based on astm specifications for various grades of rebar, the ultimate tensile strength to break rebar can range from 50 kn 11 kip to 600 kn 5,000 lbf for one size of rebar. A tensile test machine able to apply a tensile force greater than the ultimate tensile strength of the. Astm standard reinforcing bar card inlb crsi resource. Grade 100 690 reinforcing bars were introduced in this specification in 2015. Pdf on nov 1, 2015, moses a ogunbiyi and others published comparative analysis of the tensile strength of bamboo and reinforcement steel bars as structural member in building construction find. Deformed steel bars have ribs, lugs and indentation on the surface of the bar, which reduces the major problem that is faced by mild steel bar due to slippage and good bonding is achieved between concrete and rebar.
A reduced gage section specimen made from 6061t6 aluminum, ready for tensile testing. Material products standards exist to help ensure that rebar produced throughout the world exhibits the same. Rebar is used to enhance tensile strength in concrete. Standard test methods for testing mechanical splices for. Nos of rebar sample 4, length of rebar sample about 600 mm. There are different grades for tmt reinforced steels namely fe 415, fe 500, fe 550, fe 600, where the numbers denote the minimum yield strength. Furthermore, an evaluation of the existing recommendations for the spliced frp bars aci 440. Pdf 9 users english, pdf 5 users english, pdf 3 users english, pdf 1 user.
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