Reinforcing bar arrangement has become denser due to highly required seismic performance. Mechanical splices are selected for various reasons. Observations of cracking behavior, strain measurements of reinforcement, and strength are reported. Hrc 400 mechanical splices are dimensioned to exceed the actual stress. Methods of splicing reinforced bars the constructor. Designdetailing supplements, key publications this popular publication is the definitive source for information on development and splicing of reinforcing bars. Recommendations for spacers, chairs and tying of steel reinforcement reliability considerations for hydraulic variables. Reinforcing bar splices engineering technical note etne1 objective the purpose of this technical note is to offer an introduction to steel reinforcing bar splices and is intended primarily to readers with limited experience with this subject.
Anchorages and joints in reinforcing bars previous guideline on joints in reinforcing bars was published in 1982. A lot of technologies of anchorages and joints have been. The current masonry standards joint committee msjc provisions are conservative in predicting the strength of the splices. For lap splices, contact splices are preferred for the practical reason that, when wired together, they are more easily secured against displacement during concrete placement. The development of the reinforcing bars relies on mechanical. Features technical data on mechanical splices including load tests for t. Features technical data on mechanical splices including load tests for type 1 and type 2 splices. A simple pipe wrench can be used to snug and secure the splice assembly. This article provides a brief overview of the current testing related to mechanical splices and the background for such tests with a specific focus on the requirements for seismic applications. Hrc theaded bars have some special characteristics which distinguish.
Jsce specifications on stainless steel bars and new. Development, splices, and simple span bar cutoffs part i concrete design and analysis fall 2002 by dr. Anchorages and splices publication available this popular publication is the definitive source for information on development and splicing of. Abstract the key factors that govern development anchorage and splice performance of reinforcing bars in tension are described. Bpi griptwist is a swaged splicing and anchorage system that incorporates the. Anchorage and splice lengths of castin reinforcement bars are defined by the applicable structural concrete design codes. Mechanical properties for splices of welded reinforcing steel bars. Reinforced concrete design development, splices, and simple. What are the types of mechanical splices for rebars. Very limited data are available regarding splices and anchorage of bundled bars. Now in its sixth edition, the book features data on mechanical splices including load tests for type 1 and type 2 splices, grades 4080. A lap splice is the predominant method used for splicing reinforcing bars. References to aashto lrfd specifications in the chapter refer to the current aashto lrfd.
Currently, limited data on the behavior of headed bars are available, with no data on highstrength steel or highstrength concrete. Reinforced concrete design development, splices, and. Dowel bar mechanical splices are used to prevent bars from penetrating or protruding. It is interesting to note that they were a feature of the earliest designs. Tension development length and lap splice design for reinforced. Anchorages and splices 6th edition 2017 crsi on amazon. Lap splices of bundled bars should be based on the lap splice length recommended for individual bars of the same size, and individual splices within the bundle should not overlap each other. Reinforced concrete structures are designed to behave monolithically. Crsis reinforcement anchorage and splices includes tables of required lap splice lengths based on these variables. Recommendations for mechanical splices of reinforcing bars pdf ceb bulletins n 201.
Additionally, the proposed model for head capacity is compared with data from the lap splice study. A lot of technologies of anchorages and joints have been developed. This publication is a source for information on development and splicing of reinforcing bars. Compression only mechanical splices or end bearing splices. Includes extensive tables of development and lap splice. The concrete strains in the section at midheight of the column. Buy reinforcement anchorages in splices da 2 on free shipping on qualified orders. The wording of this clause has remained unchanged since the rules for calculating. Although welded splices can gave continuity of the bars, while there is still some serious question. Special hardware permits use for end anchorages in concrete or connection to. Headed reinforcing bars serve as a viable alternative to hooked bars for anchorage in concrete because they provide a more efficient anchorage mechanism and limit congestion of the reinforcement. Pdf anchorage of headed reinforcing bars in concrete.
Crsi reinforcement, anchorages and splices, 5th edition 2008. Lap splices should not be used for bars larger than no. Crsi reinforcement, anchorages and splices, 5th edition. Because mechanical splices do not rely on the surrounding concrete to transfer the force between bars, splitting failures are not a concern, and the strength of the splice is not sensitive to the compressive strength of the concrete or the amount of cover. Anchorage and lap splicing detailing of slabs, columns. Fax 8002450329 3 splices glossary of splicing terms glossary of splicing terms splice a splice may be considered as two or more conductors joined with a suitable connectorreinsulated, reshielded.
Includes extensive tables of development and lap splice lengths for grade 60 uncoated and epoxycoated reinforcing bars with 3,000 to 10,000 psi concrete compressive strengths. Nov 03, 2017 new, fullyupdated edition of reinforcing bars. The msjc provisions including a modification factor recently. Headed bars are often used to anchor reinforcing steel as a means of reducing congestion where member geometry precludes adequate anchorage with a straight bar. This site is like a library, use search box in the widget to get ebook that you want.
Foreword special anchorages for the ends of reinforcing bars are almost universally used in reinforced concrete construc tion. Features technical data on mechanical splices including load tests for type 1 and type 2 splices, grades 40 to 80. Mechanical splices in reinforced concrete construction should meet the building code requirements for developing tension and compression as required. Jsce specifications on stainless steel bars and new anchorage. Properly designed splices of individual reinforcing bars are a key element in transmitting forces through the structure and creating a load path. Reinforcement can be developed by embedment length, hook, or mechanical anchoring device. Aci 31805 prohibits splicing entire bundles, and uses multipliers to increase the required development and splice.
European ec2 and aci 31808 design code rules for lap splices of reinforcing bars within a bundle differ markedlythe former permits the same or shorter lapsplice lengths with respect to. Effect of preexisting cracks on lap splice strength of. Anchorage and lap splicing of large diameter bars needs much space and rebar material, because of long anchorage and lap lengths and large bending radius. Mechanical reinforcing bar anchorages shall be the coldswaged taperthreaded coupler type, which shall be assembled with 5a b or 10a b heads specify head size bar tostructural steel connections shall be the coldswaged taperthreaded weldable. The welded splices and mechanical splices require more labour and skill compared to lap splicing. Results from the tests of the lap splices indicate that transverse reinforcement restrains tension cracking in the masonry and improves splice performance. The splicing of bars should be carried out for alternate bars if more than one bar has to be spliced. Beams in this group had a nominal side clear cover of 2. Noncontact lap spliced bars should not be spaced too widely apart, permitting a zigzag crack in the concrete between bars. T h e re f o re proper splicing of rebars becomes essential to the integrity of reinforced concrete. Anchorages and splices is the definitive source for information on development and.
Reinforcing bar splices are key components in reinforced concrete construction. This research aimed to experimentally study the anchorage behavior of headed reinforcement in lap splices. Further they start to splice next column, same time other workers assemble the. The wedge passes between the bars and extends through a hole opposite the hole of insertion. This popular publication is the definitive source for information on development and splicing of reinforcing bars. Now in its sixth edition, the book features data on mechanical splices including load tests for type 1 and type 2 splices, grades 40 to 80.
For tension splices where the area of the bars is twice that re q u i r ed by stru c t u r al analysis, the splices can be designed for less than 125 percent fy of the bar. A more indepth dis cussion can be found in the references listed at the end of this technical note, including crsis publication reinforcing bars. In the field, reinforcing bars are cast in concrete with the flanged coupler attached to the form face. Top bars and other bars lap splices msucog civilenvironmental 7 jan 08 20.
For these reasons aisc 2005 permitted the reduction in the design strength of the welded bars to 0. The purpose of this technical note is to offer an introduction to steel reinforcing bar splices and is intended primarily to readers with limited experience with this subject. The length of lap should be increased 20 percent for a 3bar bundle and 33 percent for a 4bar bundle. This popular publication is the definitive source for information on. In both columns, some bars had three strain gauges and others five, as shown in figure 4b. Generally, the transfer of load between reinforcing bars is achieved by lap splicing the bars. In the presence of a simulated crack in the plane of the reinforcing bars, the three specimens with lapspliced no. Prequalification of mechanical splices for reinforcing bars. Observations of headed bar anchorage have shown that the final anchorage capacity consists of peak head bearing and reduced bond. Why anchoring of reinforcing bars necessary and what are the shapes. Reinforced concrete design chapter development, splices, and. Behaviour of beam lap splices under seismic loading. Development, splices, and simple span bar cutoffs slide no. Evaluation of bundled bar lap splices researchgate.
Introduction to steel reinforcing bar splices default. Reinforcement, anchorages and splices, 5th edition 2008 now available. Anchorages and splices 2008, where extensive design tables. Tension bars a b bars x bars y plan view bars y bars x continuous ld single layer a a elevation view section aa bars y s s figure. Ence 355 assakkaf compression bars qdeformed bars in compression the method for determining the development length in. Findldb according to code, use the modification factors. Splices definition of splices by the free dictionary. Behaviour of contact and noncontact lap compression splices. Code rules for laps and anchorages of individual bars have been validated against an extensive set of physical test data on splices and anchorages of individual bars in which these parameters vary over a wide range. Prequalification of mechanical splices for reinforcing. Anchorage of the full tensile capacity of the rebar prevents premature pullout failure. In order to read a secure pdf, you will need to install the fileopen plugin on your computer.
Experiments of lap splices with highstrength headed bars were conducted to investigate the anchorage behavior of highstrength headed reinforcement. The concrete reinforcing steel institute has released an updated version of reinforcing bars. The behavior of headed bars in lap splices is compared to the behavior and trends observed in the cct node study. Nov 06, 2017 the concrete reinforcing steel institute has released an updated version of reinforcing bars. Includes extensive tables of development and lap splice lengths for grade 60 reinforcing bars with 3,000 to 10,000 psi concrete compressive strengths, and development and lap splice tables for epoxycoated reinforcing bars, including development. Behaviour of contact and noncontact lap compression. Required lap for tension splices, may be stated in terms of development in tension ld. The lap splice is the most common and economic splice employed in the construction. Why anchoring of reinforcing bars necessary and what are the shapes answer akhilesh chandra if the actual available length is inadequate for full development, special anchorages must be provided, such as cogs or hooks or mechanical end plates. Further they start to splice next column, same time other workers assemble the formwork.
These bars were close to the corners diagonally opposite of the columns, as shown in figure 4a. Pdf mechanical properties for splices of welded reinforcing. The wedge pin is driven with a handheld hydraulic ram. The use of reinforcing bar couplers or mechanical splices in reinforced concrete construction is on the increase. The spacing between the bars, the splice bar blockout length, and presence of transverse bars were varied to study the effectiveness of the.
Splicing bar concrete reinforcing steel institute crsi. Click download or read online button to get reinforcing bars anchorages and splices book now. The results indicate that strutandtie modeling can be successfully applied to understand the behavior of noncontact lap splices and is necessary in determining the anchorage length of lapped bars. In this research, eight tbeam specimens with noncontact lap splices were tested.
Now in its sixth edition, the book features data on mechanical splices including load tests for. Headed bars of grade 600 mpa were used and main variables include splice length, spacing between bars, bar diameter, concrete strength, and confinement. A more indepth dis cussion can be found in the references listed at. Anchorages and splices 10 splices 2017 december 28, 2019 december 21, 2019 admin. Updated edition of reinforcing bars publication available. Reinforcing bars anchorages and splices download ebook. For comparison purpose an incremental tensile load tests were carried out on welded splices as shown in figure 4 a and coupler splices and or mechanical splice as shown in figure 4 b. The definitive source for information on development and splicing of reinforcing bars. Although there is a small amount of test data on anchorage. The spacing between the bars, the splice bar blockout length, and presence of transverse bars were varied to study the effectiveness of the splices. Thaddeus hyatt, in his beam tests of 1876 and 1877, used anchorages. After the formwork is removed, straight or bent splice bars are installed into the coupler to extend the reinforcing bar. Recommendations for mechanical splices of reinforcing bars. Klingner research report 18553 research project 01855 explore new uses for theaded bars in structural concrete reinforcement applications conducted for the.
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