Crsi staggered lap splices Inspection is a time consuming task, and one requiring workers to perform to the best of their ability. I see a lot of the newer material (specifically the 2002 CRSI Design 4. Tension lap splices of reinforcing bars in tie members are not ACI 318 section 12. 2 ld by 40 cm using K-400 concrete and calculation analysis produces the Column verticals can be spliced by lap splices, mechanical splices, or welded splices. 3 times the lap length. For bars in compression, the rules are different. Re-Bar Staggered Lap Splices - Free download as PDF File (. 9781943961399. b) Lap splices shall be considered as staggered if the centre to centre distance of the splices is not less than 1. Lap splices are ineffective for longer spans, are not regarded as reliable under cyclic pressure, and have a lot of hidden expenses . The minimum distance between staggered splices for reinforcing bars shall be the length required for a lapped splice Column verticals can be spliced by lap splices, mechanical splices, or welded splices. Lap splices length testing conducted to determine the distribution of force occurs. This paper reports an investigation into the performance of lap splices of individual bars Contact CRSI CRSI Headquarters 933 North Plum Grove RoadSchaumburg, IL 60173-4758 Phone: 847. 4 Design and Detailing the Transverse Reinforcement 5-9 5. The first control had continuous rebars, whereas the second control had lap splices. CRSI LAP SPLICES A lap splice is when two pieces of rebar overlap to form a continuous reinforcement. in JP 62:635–650, STAGGERED SPLICES—Splices in reinforcing bars which are not made at the same plane. 2 Vertical Transfer 5-23 In this study, eight glass fiber–reinforced polymer (GFRP)-reinforced concrete beams were tested in flexure. 00: Non Keywords: development, lap splices Reference: Concrete Reinforcing Steel Institute-CRSI [2015], “Tension Development and Lap Splice Lengths of Reinforcing Bars Under ACI 318-14,” CRSI Technical Note ETN-D-1-15, Concrete Reinforcing Steel Institute, Schaumburg, Illinois, 8 pp. 4 Individual bar splices within a bundle shall not overlap. Lap splices length (ld) serves to channel the force borne by the steel reinforcement. The problems of bar spacing, type of bar deformations and lap length were investigated by Chamberlin (2), Walker (9), and Chinn et al (3). Find the most up-to-date version of CRSI REINFORCEMENT at GlobalSpec. I see a lot of the newer material (specifically the 2002 CRSI Design Handbook) uses something called "Lap Classes" types A and B. Re-Bar Staggered Lap Splices CRSI digital publications for purchase use a Staggered Lap Splices: Member $0. Hence, staggered lap splices are expected to exhibit a less brittle performance [11], [12 encourage staggering of steel bars. Features technical data on mechanical splices including load tests for Type 1 and Type 2 splices. 6. For high walls, only 50 percent of the main flexural reinforcing steel is lap spliced at Contact CRSI CRSI Headquarters 933 North Plum Grove RoadSchaumburg, IL 60173-4758 Phone: 847. A lap splice is the predominant method used for splicing reinforcing bars. pdf), Text File (. clear cover provided. that was characterized by stirrups and staggered lap-splice, G (B) Updated and expanded development and lap splice length tables for uncoated, galvanized and epoxy-coated grades 60, 80 and 100 deformed reinforcing bars, standard hooks, headed bars, and deformed wires and deformed plain welded wire reinforcement in 3,000 psi to 10,000 psi concrete. Therefore, either the IBC code sections governing concrete or ACI 318-14, current as of Based on these findings, a preliminary model is developed to describe the bond-stress profiles in lap splices, after the yielding of the bars. The lapped sections of contact lap splices are wired together. 1 Walls with non‑staggered lap splices Four walls with non-staggered lap splices (W60U, W80U, W60C, and W80C) were tested at Purdue University. allowed when the criteria of 3. Mech-anical splices do not rely on the con-crete for load transfer. Be sure to include all relevant information, so [] $39. 2008 Columbia Road Wrangle Hill, DE 19720 +302-836-3880 [email protected] Bar splicing is considered an essential part of the construction process of reinforced concrete (RC) due to the ease of installation in construction, transportation constraints, and restricted length of reinforcing bars. The two upper splices (A and B) are bolted steel sleeves. Researchers are conducting earthquake testing to better understand the performance of a construction technique called staggered lapsed splices, which is used to First step of the procedure is to calculate the number of these extra stirrups. 4(1) and Figure R611. Where splices are staggered in location such that not more than Tensile Strength of Lap Splices in RC Members Research Note RN-2011-1 - 8 pp. (20. Performance of lap splices is greatly dependent on different parameters (representing the bond mechanical mechanism between concrete and reinforcement bars) including concrete cover, lapped length, the proportion of lapped bars, reinforcement bar diameter, transverse reinforcement considered at the vicinity of the splice, concrete Column verticals can be spliced by lap splices, mechanical splices, or welded splices. Lower values may be obtained by using equation 12-1 in Section 1912. Layering Reinforcing Bars M any walls and slabs are reinforced with a single curtain of reinforcing bars comprising two orthogonal layers. Elimination of lap-splice calcu-lations. 3 ld) 27 cm and 30 cm using concrete with compressive strength of 400 kg/cm2 and 450 kg/cm2 . 2. 5 CRSI Recommendations to Architects/Engineers for Splices of Features technical data on mechanical splices including load tests for Type 1 and Type 2 splices, Grades 40 to 80. Lap splice details, including lap length, should be based on testing and installed in accordance with the manufacturer’s recommendations. , 1997. 1 requires that welded or mechanical splices be staggered 24 inches. The Code language is just not clear to me though from a mechanics standpoint, I would think that For Class A lap splices, the required tension lap length is the equal to the tension development length (anchorage length). 15. Splicing rebar with lap splices must be done in its implementation due to the influence on the methods of implementation and the availability of existing reinforcing steel length. 2 Requirements for SDC A and B 5-9 5. EXPERIMENTAL WORK Specimen details A total of 70 beam specimens with tension reinforcement lap-splices were tested. b. The new edition conforms to ACI 318-14 and AASHTO LRFD Bridge Design Specifications, 2016. A staggered arrangement of the lap splices subsequently reduces the localized stresses at each lap location, and lowers the possibility of concrete cracking (splitting) or reduces the crack widths. 2 (or 25. The project inspector has rejected the laps, saying they must be one square plus 2 inches, or 8 inches total, minimum. Following this discussion, a development and lap splice tables are presented. (DOI: 10. Also included are extensive tables of development and A staggered arrangement of the lap splices subsequently reduces the localized stresses at each lap location, and lowers the possibility of concrete cracking (splitting) or reduces the crack A staggered arrangement of the lap splices subsequently reduces the localized stresses at each lap location, and lowers the possibility of concrete cracking (splitting) or reduces the crack I've always used the standard ACI 318 equations for determining tension and compression lap splices. bars or lap splices in a single layer, in. 2, or 3. Class B splices, except that Class A splices shall be. 3. Bond behavior Splices; Coatings; Tolerances, including fabricating and placing; In-Situ Bending and Rebending Reinforcing Bars; Field Cutting of Reinforcing Bars; Lap Splices, Mechanical Splices, and Welded Splices; What the Inspector Needs to Know. According to ACI 318–19 [21], CSA A23. Lap splicing of #14 and #18 bars is not permitted by the ACI Code, except in compression to smaller size dowels at footings. 20 Field Failures in reinforced concrete (RC) structural walls have been reported to occur at longitudinal lap splices in earthquakes as far back as 1964 (Kunze et al. Both contact and noncontact lap splices that satisfy Section 25. 1(b). Laps in reinforcement should always be staggered. 1206 Please use the form below to contact CRSI. This EAD covers couplers for mechanical splices of reinforcing steel bars for concrete (in the following referred to as couplers) with sizes ranging from 8 to 50 mm with the following property: A s,nom,bar ·R e,nom,bar ≤ A s,nom,coupler ·R e,nom,coupler The load bearing parts of the couplers are completely made of steel or cast steel. 1 Test setup, units, and loading. 1200Fax: 847. Tension lap splices of reinforcing bars in tie members are not It is evident from the results that the column containing lap splices within its critical region had the largest strength but the poorest ductility performance. a) Lap splices shall not be used for bars larger than 36 mm; for larger diameters, bars may be welded (see 12. 5. General question regarding proper splicing detail of bundled bars in piles and columns: AS3600 and AS5100. 1 Overview 1-1 1. Although lap splice is easy and cheap in construction, it has also some disadvantageous such as CRSI - Field Inspection of Reinforcing Bars - Free download as PDF File (. 00: Non b) Lap splices shall be considered as staggered if the centre to centre distance of the splices is not less than 1. 00: Non ACI 318-19), which defines lap splice length ℓ st of deformed bars or wires in tension. pdf. 2 Example Buildings 1-2 %XLOGLQJ ± 6WRU\ 2I¿FH %XLOGLQJ CRSI digital publications for purchase use a Staggered Lap Splices: Member $0. Its remarkable bond strength enables non-contact lap splices for longitudinal bars (Dabiri et al. Discover the world's research. 7 Detailing for Constructability – 6-22 The topics include circular tie details and required lap splice lengths for circular ties; detailing hooks in shallow sections; and use of side-by-side and staggered lap splices. A traditional volume fraction of hooked steel fibers (equal to 0. Title: Lap Splices of Bars in Bundles Author(s): John Cairns Publication: Structural Journal Volume: 110 Issue: 2 Appears on pages(s): 183-192 Keywords: bond strength; brittleness; bundles; lap splices DOI: 10. 1 in the 2002 ACI Building Code lists 13 items that must be shown on design drawings or in project spec-ifications. 2 Tension Lap Splices 2-1 2. Updated and expanded development and lap splice length tables for uncoated, galvanized and epoxy-coated grades 60, 80 and 100 deformed reinforcing bars, standard hooks, headed bars, and deformed wires and deformed plain welded wire reinforcement in 3,000 psi to 10,000 psi concrete. 19 Special Services and Items 4-6 4. In this study we reviewed ACI (2002), BNBC (1993), AASHTO (2007), CEBFIP Further information on mechanical splices is presented in the CRSI publication, Reinforcement Anchorages and Splices, 4th Ed. 5%) was adopted for FRC. The important considerations on length, location, and position of lap splices as per IS 456-2000, clause. cracking, lap splice, reinforcing bar, stagger Reference: Concrete Reinforcing Steel Institute - CRSI [2013], “Staggered Lap Splices,” CRSI Technical Note ETN-D-2-13, Schaumburg, Illinois, 4 pp. 6 Mechanical Splices 8-8. 2" L s 54D 40D 3lD 26D 19D These lengths apply where all bars are spliced at the point of maximum moment and assume at least a 2 in. Be sure to include all relevant information, so [] CRSI digital publications for purchase use a Staggered Lap Splices: Member $0. Fig. Required Development and Lap Lengths for Grade 60, Uncoated Bottom Reinforcement in Normal Weight Concrete ACI 318 Chapters 18 and 25 state the requirements for mechanical splices. Transportation and handling limitations have an effect on the maximum length of the reinforcing bars and very often the bars must be spliced in the structure on site. However, the In this study tension and contact lap splices are considered. For instance, the Class B lap splice ℓ st is the greater of 12 in. 2012 IBC Lap Splices With Confinement Reinforcement. 0%. Specific guidelines on lap splices are given in ACI Chapter 13. 3 times the required lap length of the bars. 17 Fabrication of Reinforcing Bars 4-6 4. By using an experimental study in which the use of reinforcing steel D-10 with a lap splices length of 1. Specimens 2 to 7 consisted of non-contact lap splices where the distance between the dowel bars and the column longitudinal bars ranged from 4 in. (mm) fc′ = specified compressive strength of concrete, psi (MPa) f c′ 1/4 = fourth root of f ′, expressed in psi (MPa) units This is given in the cl. (203 mm). Upvote 0 Downvote. 4 (1). 5 Typical Bend Shapes, Measuring Points, 6-12 Fabrication Tolerances and Standard Hooks 6. It requires a fully welded splice or full mechanical connection with splices in adjacent bars staggered at least 800mm (32"). For lap splices: i. When staggered lap splices are used, splice strength may be enhanced by the better confinement of the concrete cover because the bars are widely spaced. Welded lap splices using a “back-up” plate may also be used. 0 and 1. When they are required, it is the designer ’s responsibility to clearly dene the staggered lap Table 1 — Stagger Requirements for Lap Splices, per ACI 318-11 Condition Stagger Distance Code Section Individual bars within a bundle need to terminate at different points with at least a 40 d b stagger. Bar sizes No. Personally, I have never lap spliced such large bars. (600 mm) and applied to alternate verticals. 1 Typical Bend Shapes, Measuring 6-12 Points and Fabrication Tolerances 6. Contact splices–in which the bars touch and are wired together–are 6. Dec 20, 2011; Thread starter #8 abusementpark noncontact lap splices are permitted subjected to the limit of 6" or one-fifth the splice length whichever is less. ACI 318M-14 Table 25. c) For direct tension lap shall be 2Ld or 30dia whichever is greater. Compression splice sleeves. Laps splice in reinforcement should always be staggered. crsi. 6" 5 7. Two items, 1. Rebar placement does not require that level of precision. 2. On the contrary, the column containing lap splices outside its critical region had strength and ductility comparable to those of the column without lap splice. 3 – Using Stock Length of Bars Cut and Spliced in Field Use lap spliceswhenever possible. A lap length of 40 times rebar diameter was used in tension in the constant moment region. 2 of IS 456:2000 suggests 100% design strength be . Is the 24 inches measured center to center or end to end? 2. Thicker walls or slabs are usually reinforced with a two-layer curtain at each face. When lap splices are required to be staggered by a certain distance (say 30"), is that distance measured from the center of the splice to the center of the adjacent splice? Or is When they are required, it is the designer ’s responsibility to clearly dene the staggered lap Table 1 — Stagger Requirements for Lap Splices, per ACI 318-11 Condition Stagger Distance Code Section Individual bars within a bundle need to terminate at different points with at least a 40 d b stagger. They are: Type 1 Mechanical Splice . Mechanical splicing does away with the tedious calculations needed to determine proper lap Technical Note Engineering Technical Note ETN-D-2-13 Staggered Lap Splices Introduction Lapped splices are probably the most common means of joining two lengths of reinforcing bars. Class A splices are up to 30% shorter, but can only be used if the members are over-reinforced and all the splices are staggered. 3 times the lap length calculated. Download Citation | Staggered lap joints for tension reinforcement | Staggering lapped joints increases the complexity of detailing and steel fixing, and may require additional resources and slow 2. Includes extensive tables of development and lap splice The purpose of this Technical Note is to provide education of the staggering of lap splices to avoid reinforcing bar congestion in the lap splice region. Source: FHWA/CRSI Continuously Reinforced Concrete Pavement Design & Construction Guidelines. ; 6th Edition/2017/ISBN No. 16 Designing with Specialty Reinforcing Bars 4-6 4. Be sure to include all relevant information, so [] Concrete international OctOber 2011 59 RFIs on Circular Ties, Rotating Hooks, Staggered Lap Splices, and Closure Strips rFIs 11-05, 11-06, 11-07, 11-08, and 11-09 In Our Company. Historical: None. 1 Overview 5-23 5. 57 Staggering of The lap splices were located at the bottom section of the first column and at the middle part of the second one, which represents the lap splice requirements for RC columns in Turkish Earthquake An experimental study, where1-cm-diameter lap-splices length of reinforcing steel bar were used, was (1. Staggered Lap Splices Introduction Lapped splices are probably the most common means of joining two lengths of reinforcing bars. With lap splices length 27 cm and 30 cm using quality of concrete K-400 occur in lap splice collapse after passing the yield stress of reinforcing steel 40 kg/mm 2. Extending existing reinforced concrete structures such as slabs, walls and columns is the most common application for post-installed reinforcing bars. Of the three, lap splices are the most economical, and so, should be used whenever possible. Download Citation | Lap Splices of Bars in Bundles | European (EC2) and ACI 318-08 design code rules for lap splices of reinforcing bars within a bundle differ markedly-the former permits the same It requires a fully welded splice or full mechanical connection with splices in adjacent bars staggered at least 800mm (32"). 0 times prolonging the service life of piers. Class A lap splices may be used where: (a) the area of reinforcement provided is at least twice that required by analysis over the entire length of the lap splice; and (b) one-half or less of the total reinforcement is spliced within the required lap splice length. After a brief description of welded shop splices, this volume focuses on the factors which influence and the principles of the design of bolted field splices. Suggest avoiding the proposed splice detail circled in red on the marked up illustration shown below. Tension lap splices of reinforcing bars in tie members are not Bars spliced by noncontact lap splices must be spaced no farther apart than one-fifth the required length of lap and no more than 8 in. zone-A ( L/4 length ) should be avoided as there will be a maximum moment in this zone due to lateral forces acting on the column. Be sure to include all relevant information, so [] This requires the following lap lengths: sID = 3 S 4. Two questions: 1. 3 times the development Determining the Proper Development Length for Lap Splicing High Strength Grade 100 ChromX® Steel As Per ACI 318-19 Rebar Splicing Solutions ENGINEERING BULLETIN #8 The process for determining the development length of ChromX® steel conforming to ASTM A1035/A1035M design strength at 100 ksi is in accordance to the Except as specified, lap splices in tension shall be Class B splices. lap a sL sb Note: For the purposes of determining cd, the dimension a shall be taken equal to 2sL irrespective of the value of sb. 517. 4. Lap Splices The lap splice is the most common and economic splice employed in the construction. The experimental programme, as well as some relevant There are, however, inconsistencies in the value of the coefficients to be applied, and little evidence is available for validation. 45 and No. 3 *Table Based on Uniform Building Code (ICBO, 1997), Section 1912. Scribd is the world's largest social reading and publishing site. e. development and lap splice tables are presented. The development lengths and lap splices are provided assuming that all bars may be spliced at any one location. 6. 4 Lap Splices 6-12 6. may be more than the cost of field cutting and lap splicing. 1(i), are concerned with anchorage 2. It reflects the effect of length, cover, spacing, bar diameter, concrete strength, transverse reinforcement, and moment gradient on the strength of lap splices. Following this discussion, a Lap splices. Note: This publication is intended for the use of professionals competent to evaluate the Keywords: development, lap splices Reference: Concrete Reinforcing Steel Institute-CRSI [2015], “Tension Development and Lap Splice Lengths of Reinforcing Bars Under ACI 318-14,” CRSI Technical Note ETN-D-1-15, Concrete Reinforcing Steel Institute, Schaumburg, Illinois, 8 pp. File sharing on the ENG-TIPS Forums is outsourced to ENGINEERING. When on e 5. Lap splices shall not be used for bars larger than 36mm; for larger diameters, bars may be welded, in the case where welding is not practicable, lapping of bars larger than 36mm may be permitted, in which case additional spirals should be provided around the lapped bars. Splices serve the primary role of joining reinforcement bars in standard RC elements such as columns, walls, beams, slabs, and joints. Lap Splices A lap is when two pieces of rebar overlap to form a continuous line. This expression is based on a nonlinear regression analysis of test results of beams with lap splices and reflects the effect of length, cover, spacing, bar diameter, concrete strength, and transverse reinforcement on the strength of anchored bars. The vertical bars are L-shaped and serve as vertical, dowel, and foot - ing reinforcement. lap ≥ 0. 4 The values stated in either SI units or inch-pound units 3. It is recommended that staggered splices are only used when they are essential to the design of a structure due to the complexity they add to both the detailing and placement of It addresses questions about circular tie details for drilled shafts, including acceptable alternatives to lapping ties around a single bar. (10. Since lap splices transfer load through the surrounding concrete, when the concrete is gone, the lap splice in effect has failed. Requirements for development length as well as lap, mechanical and welded splices are identical to those for allowable stress design, and are presented in Tables 4a through 4d. ; 2013 This Research Note describes the results of a study conducted at Purdue University, the tensile strength of unconfined deformed-bar lap splices with different lengths was re-examined. Tests 1, 7, 29, 30, 47, 48, and 56 were conducted Caution, sales pitch: For field personnel, CRSI's "Placing Reinforcing Bars" covers most placing issues encountered by placers and inspectors. 6 CRSI Recommendations 1-1 Identiocation Marks— 1-Chapter ASTM Standard Reinforcing Bars; Welded Wire Reinforcement (WWR) 2-2 Introduction 2- 8. The cost of additional length of bar is usually less than the cost of material and labor for mechanical splices. walls, lap splices of vertical reinforcement can be avoided entirely. The rebars are staggered and lapped correctly so that they maintain the clear cover of the column. However, the Lap splices in columns are definitely permitted by ACI 318. ACI code section 318-14, which governs rebar splicing, has been incorporated without meaningful modification into the corresponding concrete section of the 2015 and 2018 IBC. 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 epoxy-coated reinforcing bars, including development length tables. See Fi g u r e 4. Of course, the splices should be staggered. If all the bars are spliced at the same location, the slices need to be Class B = 1. This paper reports an investigation into the performance of lap splices of individual bars Yeah, this comes from ACI 318-14, 25. 4. One is a cylindrical shell with bolted flanges at one side; the other is a half-cylinder The paper presents experimental results on lap splices in Fiber Reinforced Concrete (FRC). performing wall had staggered lap splices, and a drift ratio at first failure of just 1. A2. It is one of the most common reasons for forming rock pockets and voids in concrete. 3 Epoxy-Coated or Dual-Coated 8-8. In either case, it is necessary to consider the bar b. lating the tension development or tension lap-splice length (Section 12. The 2012 IBC, by reference to the 2011 MSJC, includes new lap splice criteria where confinement reinforcement is placed. 16 cm) to 8 in. org for more For Class A lap splices, the required tension lap length is the equal to the tension development length (anchorage length). 57 given below. Ma et al. 3 Galvanized Reinforcing Bars 8- cations for tension lap splices result in long lap splice lengths, especially for bar sizes such as #9, #l0, and #ll in Grade 60 steel or in epoxy-coated reinforcing bars. 2" 4 5. The key factors that govern development (anchorage) and splice performance of reinforcing bars in tension are described. 15 Splices 4-5 4. Please visit resources. 00: Tensile Strength of Lap Splices in RC Members: Member $0. 3 Spacing and Cover #6 and Smaller Bars #7 and Larger Bars • Clear spacing of bars being developed or lap spliced • Clear cover University of Canterbury research into the technique used to connect reinforced concrete walls to their foundations is set to have a significant impact on the New Zealand construction industry. My question is whether noncontact lap splices in columns are permitted by ACI. 3 Splices of Longitudinal Reinforcement 5-4 5. Welded laps splices with bars in contact are re c o m - mended only for # 5 bars or smaller. Compared to lap rebar splicing, the welded rebar splices and mechanical rebar splices require more labor and skill. Verify lap splicing is staggered in accordance with the Contract Documents. Measure the lap splice length in the field and verify that the minimum required lap splice length has been met . 1 or ACI 318M-11 Hence, staggered lap splices are expected to exhibit a less brittle performance [11], [12], [14], [20]. Splices shall be staggered. CRSI splices have long been an accepted construction practice, the literature in this area was rather limited. UNLIMITED FREE ACCESS TO THE WORLD'S Features technical data on mechanical splices including load tests for Type 1 and Type 2 splices. Where splicing method was the primary variable, a wall with staggered lap splices had a drift ratio at first failure of 1. To quantify the bond strength for design purposes, a sound Contact CRSI CRSI Headquarters 933 North Plum Grove RoadSchaumburg, IL 60173-4758 Phone: 847. The paper presents experimental results on lap splices in Fiber Reinforced Concrete (FRC). 5 Force Transfer at Base of Columns 5-23 5. 14359/51684399 Date: 3/1/2013 Abstract: European (EC2) and ACI 318-08 design code rules for lap splices of reinforcing bars within a bundle differ Technical Note Engineering Technical Note ETN-D-2-13 Staggered Lap Splices Introduction Lapped splices are probably the most common means of joining two lengths of reinforcing bars. Staggering the lap splices is sometimes required by the designer, basically for two reasons: (1) to reduce reinforcement congestion in locations where there is a relatively heavy amount of Contents Foreword Acknowledgements Photo Credits Chapter 1 Introduction 1. Note: This publication is intended for the use of professionals competent to evaluate the Contact CRSI CRSI Headquarters 933 North Plum Grove RoadSchaumburg, IL 60173-4758 Phone: 847. CRSI staff also corrects an incorrect statement on lap splice lengths on page 51 of “Closure Strips and Lapped Reinforcement” (Concrete International, V. 00: Technical Review on Durability of GFRP: 15-20 Yr Bridges: Member $0. 1(h) and 1. Lap (40 feet maximum) and staggered where possible. Lap splices constructional details are widely used for connecting prefabricated parts. 3 l d. 4 Also included are extensive tables of development and lap splice lengths for Grade 60 uncoated and epoxy-coated reinforcing bars with 3,000 to 10,000 psi concrete compressive strengths. 3 Compression Lap Splices 2-1 2. The design of post-installed lap splices typically relies on provisions derived from cast-in-place reinforcing bars (rebars). The bond design provisions of the AASHTO (American Association of State Highway and Transportation Officials) LRFD (Load and Resistance Factor Design) Bridge Design Specifications, the American Concrete Institute Building Code (ii) 50% staggered splices PLANAR VIEW Lsy. NOTE 1—Various code-writing bodies specify various parameters, such as test loads, number of cycles and test temperature, for testing. Fabrication of that detail is an unnecessary expense. 40 d b minimum Section 7. To classify a lap as Class A, it must comply with onerous conditions defined in the table below. 4 European (EC2) and ACI 318-08 design code rules for lap splices of reinforcing bars within a bundle differ markedly-the former permits the same or shorter lap-splice lengths with respect to splices of individual bars, while the latter requires longer laps. (1975, 1977). Type "B" being either worst case or more conservative depending on the definition. In cases where permission is granted to splice bars, other than those shown on the DRAWINGS, the additional material required for the lap shall be furnished by CONTRACTOR at CONTRACTOR’s own expense . 2 ATC/SEAOC Joint Venture Training Curriculum: Longitudinal steel lap splice is always required in reinforced concrete (RC) columns. Calculate the minimum required lap splice using field verified dimension and grade of the reinforcing bar. 00: Non-Member $0. 1 INTRODUCTION. The latter is especially detrimental for fatigue resistance to repetitive stress reversals. In addition, the splices must also be designed as tension splices. The slots in the webs have been designed to accommodate this (see Figure 3). An example of a two-layer curtain is Curtain A in Fig. Alternatives to Lap Splicing Mechanical splices are required to have the bars connected to develop at least 125% of the specified yield strength of the bar in tension or compression, as required. 3ℓ d, where ℓ d is per Table 25. Be sure to include all relevant information, so [] Results from these six tests are added to a dataset of 15 previous tests of walls with non-staggered lap splices compiled by Almeida et al. Unless noted Mechanical splicing products (often called couplers) are widely used in the construction industry as an alternative to lap splices when joining two reinforcement bars, especially when there is no room for lap splices, when larger diameter of bars (larger than #11)are used, and in tension members. Abstract In this study, we evaluate the seismic performance of concrete columns reinforced with lap-spliced glass fiber–reinforced polymer (GFRP) bars through simulated earthquake loads. Where “tension tie members” are used. cations for tension lap splices result in long lap splice lengths, especially for bar sizes such as #9, #l0, and #ll in Grade 60 steel or in epoxy-coated reinforcing bars. Get informed, inspired and entertained at ENGINEERING. LAP SPLICES & DOWELS Figure 2a: Contact lap splices length of lap splices shall be in accordance with Table R611. 4); in cases where welding is not practicable, lapping of bars larger than 32 mm (as per the latest amendment) may be permitted, in which case additional spirals should be provided around the lapped bars. Bars may be spaced apart or in contact. Contact CRSI CRSI Headquarters 933 North Plum Grove RoadSchaumburg, IL 60173-4758 Phone: 847. The complete document, "CRSI Engineering Technical Note ETN-D-2-13, Staggered Lap Splices" is attached. The 6-inch max. 5 (and presumably all other relevant codes) require the individual bar splices in a bundle to be staggered by no less than the lap length. Several full-scale beams reinforced with rebars of different diameters were tested with all or part of the longitudinal reinforcement lap spliced at mid-span. When on e I've always used the standard ACI 318 equations for determining tension and compression lap splices. 18 Placing Drawings 4-6 4. There were two control beams and six beams with lap splices. Twelve full-scale reinforced concrete beams with two tension lap splices were constructed and tested under a four-point loading test. (mm) db = nominal bar diameter of developed or lap spliced bar, in. 1, 3. Lap splice lengths can be reduced if the lap splice is properly confined by transverse reinforcement per TMS 402. Half of these beams had shorter lap splices than that recommended by American Concrete Institute Building Code ACI 318-19; they failed by bond loss between steel and concrete at the lap splice region before rebar yielding. Field welded splices of bars in genera l a r e of two types: lap splices and butt splices. mechanical splices for steel reinforcing bars, but does not quantify the parameters for testing nor acceptance criteria, which must be specified. Lapping zone : When we provide lapping in a column, all the rebars should be lapped in Z one-B as shown in the drawing. There are two types of lap splices: contact lap and non-contact lap splices (see Figure 1a and 1b). shall develop in tension and compression as required at least 125% of the specified yield of the bar. 32 cm). 1 Typical Bend Shapes, Measuring 6-12 Points and Fabrication Section 1. The bond design provisions of the AASHTO (American Association of State Highway and Transportation Officials) LRFD (Load and Resistance Factor Design) Bridge Design Specifications, the American Concrete Institute Building Code 3. We installed the WWR using a lap splice of one square overlap, or 6 inches. Lap splices are usually the most economical method, but if they cause excessive congestion, problems in placing concrete, or problems of design or detailing, some other kind of splice must be used. Mechanical splices of reinforcing bars Proprietary couplers for tension and compression splices; ready and able when ordinary lap splices aren’t suitable Figure 1. Kluge and Tuma (7) conducted tests on lapped splices of bar sizes up to No. Note: This publication is intended for the use of professionals competent to evaluate the In addition, splices' confinement does not affect cyclic performance of lap splice considerably [9]. A natural dis­ continuity develops at each cutoff end, somewhat helpful in a compression lap splice and a definitely detrimental stress raiser in tension lap splices. The tests were designed to study the eects of splice length, concrete cover, transverse reinforcement details, and steel material properties on the deformability of non-staggered lap splices. CRSI’s Reinforcement Anchorage and Splices includes tables of required lap splice lengths based on these variables. 6 Lap Splices 8-8. 2 —Lap splices of deformed bars in tension shall be. 3 times smaller than a nominally equivalent wall with non-staggered lap splices and 2. 3 are. CRSI Reference Book/ 80 pp. . These areas must be identified during design and indicated on the Although the ACI 318:19 requires that the mechanical splices should have at least 25% higher design strength than lap splices, clause 26. The experimental programme, as well as some relevant walls, lap splices of vertical reinforcement can be avoided entirely. On continuous and rigid frame bridges, portions of the deck will be in tension due to superimposed dead loads and live loading. com. txt) or read online for free. 3Lsy. 2022), simplifying construction processes and enhancing connection integrity. (2021b) determined minimum splice lengths through lap splice tests, ensuring steel reinforcement yield and rupture. ACI 318 (318M) requires that mechanical splices or welded splices shall be staggered at least 24 in. Rebar congestion at the lap zone is increased by lap splicing. staggered pattern of horizontal rebar. (mm) cso = clear cover of reinforcement being developed or lap spliced, measured to side face of member, in. 8. 3 in ACI 318-19). This paper reports an investigation into the performance of lap splices of individual bars within a bundle of two or three. Lapped The lap rebar splice is the most common and economic rebar splice used in the construction project. Welded Sp l i c e s . Lap splices may thus be less practical than mechanical connections. In our design drawings, we typically show this as Using one link as an alternative for the lap splices, leads to the deficiency in mechanical properties of the welded splice, as well as the failure possibil ity will increase. Using one link as an alternative for the lap splices, leads to the deficiency in mechanical properties of the welded splice, as well as the failure possibil ity will increase. Providing a #3 or larger bar transverse to the lapped bars and within 8” from each end of the lap splice allows the lap splice length to be reduced by the confinement reinforcement factor per equation below. Specimen 1 consisted of contact lap splices in which case the dowel bars and the column longitudinal bars were in contact with each other. iii. 1. A programme of 17 physical tests found no evidence of an increase in strength when laps were staggered, and when allowance is made for increases in transverse spacing, staggering was found to reduce lap strength. Is there a similiar, or any, requirement to stagger lap splices? We've got a debate between contactor, construction manager, and structural engineer over this issue. 3 (ACI 318-14 and ACI 318-19) are included. Reinforcing Bars: Anchorages and Splices is now available for purchase through the CRSI webstore as a traditional printed book or digital download. LAP SPLICES Lap splices are treated as a special condition of stress transfer. (a/2, c ) (a/2, c ) cd = min (a/2, c) (i) 100% of bars spliced Recently Dabiri et al [14] provided a state-of-the-art review of various splice methods used for reinforcement steel bars including lap splice, mechanical splices and welded splices. 1, where they're called Class A and Class B splice types. 4 Application of ACI Code Design Requirements 2-1 2. Figure 1 shows a photo of a staggered lap splice arrangement that has been installed in the top layer of a foundation mat. For high walls, only 50 percent of the main flexural reinforcing steel is lap spliced at An equation has been developed for calculating lengths of lap splices of deformed bars from a nonlinear regression analysis of test results of beams with lap splices. • This must be equal to the total tension in all the bars that are Bars spliced by noncontact lap splices must be spaced no farther apart than one-fifth the required length of lap and no more than 8 in. job postings for engineers. 3 ld by 43 cm, 1. The term is the total cross-sectional area of transverse reinforcement within the spacing CRSI Technical Note 3 Table 4 Tension Development Lengths for Deformed Reinforcing Bars in Accordance with ACI 25. Includes extensive tables of development and lap splice lengths for Grade 60 reinforcing bars with 3,000 to 10,000 psi lengths, lap splices, mechanical splices, and mechanical anchorage. ACI 318-14 Table 25. Lap splices are permitted only within the center half of the column length and shall be designed as tension splices. 3 Requirements for SDC C 5-13 5. 14. The document A splice, in ACI/CRSI vernacular, is the attempt to achieve continuity of a single reinforcing bar. t. Divide by 1. org for more When they are required, it is the designer ’s responsibility to clearly dene the staggered lap Table 1 — Stagger Requirements for Lap Splices, per ACI 318-11 Condition Stagger Distance Code Section Individual bars within a bundle need to terminate at different points with at least a 40 d b stagger. Various design codes have provided many laws to calculate lap splice length. However, some bond characteristics of post-installed rebars show significant differences compared to cast-in-place rebars, especially when using high-performance mortars. spacing requirement is to prevent a zone of unreinforced Simple Lap Splice. Caution, sales pitch: For field personnel, CRSI's "Placing Reinforcing Bars" covers most placing issues encountered by placers and inspectors. This can be done as follows: • The total area of cross section of all the stirrups (A sv) multiplied by the ultimate stress in the steel of the stirrups (0. 7%, approximately 1. In the event shorter development and lap splice lengths are desired by IBC code requirements are almost identical to the American Concrete Institute (ACI) codes. Lap splices. Latest news, games, resources, videos and job postings for engineers. The important points to be noted while providing lap rebar splices in reinforcement bars:. 4, which covers plain wire WWR tension lap splices for structural slabs. splices are based on a bond stress equation developed by Orangun et al. This video provides an introduction to lap splices and the different types of mechanical splice devices/connectors of reinforcing steel (rebar). 2 of ACI 318-95). 00: Non Staggered Lap Splices Introduction Lapped splices are probably the most common means of joining two lengths of reinforcing bars. Temporary bracing must be provided for all dow-els to ensure proper position (plumb) and location. or 1. 6 Recommendations for Location of First 6-13 and Last Bar 6. 87f y) will give the ultimate force which these extra stirrups will be able to resist. 1 or ACI 318-11 Caution, sales pitch: For field personnel, CRSI's "Placing Reinforcing Bars" covers most placing issues encountered by placers and inspectors. STANDEE—A term used in some regions of the country to designate a special bar bent to a U-shape with 90° bent legs extending in opposite directions at right angles to the U-bend. ; Lap splices shall be considered as staggered if the centre to centre distance of the splices is The key factors that govern development (anchorage) and splice performance of reinforcing bars in tension are described. ii. 5" 8 or more 11. A total of 24 RC members, 22 of which with lap splices and two reference units with continuous reinforcement, were tested under uniaxial tension–compression cyclic loading at the structural laboratory of the École Polytechnique Fédérale de Lausanne (EPFL). Concrete international OctOber 2011 59 RFIs on Circular Ties, Rotating Hooks, Staggered Lap Splices, and Closure Strips rFIs 11-05, 11-06, 11-07, 11-08, and 11-09 In Download Citation | Staggered lap joints for tension reinforcement | Staggering lapped joints increases the complexity of detailing and steel fixing, and may require additional resources and slow Lap splices may be used for long spans as necessary, provided that they are staggered, unless otherwise approved by the project engineer. pdf - Free download as PDF File (. An equivalent analytical model of adequate reinforcement noncontact lap splices is first proposed in this study. The CRSI webs 3 = other epoxy coated 2. 1. 95/non-member FREE/members in the CRSI webstore This specification covers the design, use, and material requirements of reinforcement supports used in concrete to support various types of reinforcement, including but not limited to plain and deformed reinforcing bars, prestressing steel, post-tensioning tendons, steel wire, and plain and deformed steel welded Yeah, this comes from ACI 318-14, 25. The inspector is citing ACI 318-19, section 25. Lap Splices for Columns. From the perspectives of detailing and installation, a two-layer curtain is the most desirable. (JSE 143:853, 2017). 1 Overview 5-9 5. 00: Steel Reinforced Concrete: The Sustainable Solution: Member $0. Unless noted 1. The correct Answer Is (d) More than 1. 33, No. For lap splices, contact splices are preferred for the When lap splices are required to be staggered by a certain distance (say 30"), is that distance measured from the center of the splice to the center of the adjacent splice? Or is ACI-staggered-lap-splices. 3–14 [22] and CSA S6–19 [23] tensile lap splices are classified under either class A or B with the lap length being 1. This is shown in the fig. 3 for Class A splices or for developent lengths of deformed bars in tension 3. Normally, in countries having high seismic risk, lap splices of longitudinal steel must be located around mid TENSION LAP SPLICES Extension of existing reinforced concrete structures. Table 1 through 4 give details of the specimens. Keywords: development, lap splices Reference: Concrete Reinforcing Steel Institute-CRSI [2013], “Tension Development and Lap Splice Lengths of Reinforcing Bars Under ACI 318-11,” CRSI Technical Note ETN-D-1-13, Concrete Reinforcing Steel Institute, Schaumburg, Illinois, 8 pp. The center to center distances of laps should not be less than 1. There are, however, inconsistencies in the value of the coefficients to be applied, and little evidence is available for validation. 35 (#11) and smaller bars. 14359/51684399) European (EC2) and ACI 318-08 design code rules for lap splices of reinforcing bars within a bundle differ markedly-the former permits the same or shorter lap-splice lengths with respect to splices of individual bars, while the latter requires longer laps. Design Variables • Concrete tensile strength, f t (psi) Staggered Lap Splices Source: Caltrans Continuously Reinforced Concrete Pavement (CRCP) Design & Construction Guide. 3. 26. 0" 6 8. Each method was discussed by presenting a comprehensive description, application and installation, provisions of available design codes, benefits, limitations and possible failure modes. Despite the perceived advantages of splice staggering, questions remain regarding the ratio of bars to be spliced and its impact on bond strength. Tie Bars Tie Bar. Below is a link to the file: Staggered_Lap_Splices_CRSI. I brought up this question at work and got different answers. It also discusses lap splice requirements for circular ties 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. The topics include circular tie details and required lap splice lengths for circular ties; detailing hooks in shallow sections; and use of side-by-side and staggered lap splices. 55 corresponding to your #14 and #18 may be lap spliced with No. The lap splice of reinforcement bars can be considered as staggered if the distance between the splices is - (a) More than 1000 mm (b) More than the depth of the beam (c) More than span / 10 (d) More than 1. and whether or not lapped bars are in contact with each other, staggered, or under high or low tensile stress. Six 400 × 400 mm columns with an overall height of 1,850 mm were splice which is performed at the project site. According to this clause, the lap splices can be considered to be staggered if the centre to centre distance between the lap splices is not less than 1. 1 are explained below. 3 times the lap length L. CRSI digital publications for purchase use a Staggered Lap Splices: Member $0. The top and bottom portion of the column, i. 4 Requirements for SDC D, E, and F 5-16 5. This helps transfer loads properly throughout the structure. Moreover, the brittleness of the joint may be reduced because the continuous bars can still guarantee part of the flexural strength of the section if splice failure occurs. Field splices can be performed either on the ground prior to erection or in the erected position. Includes extensive tables of development and lap splice lengths for Grade 60 uncoated and epoxy-coated reinforcing bars with 3,000 to 10,000 psi concrete compressive strengths. The Features technical data on mechanical splices including load tests for Type 1 and Type 2 splices, Grades 40 to 80. 3 times the lap length splice which is performed at the project site. The These outcomes raise questions over the validity of EC2 and ACI 318-11 provisions which allow a reduction in lap-length when splices are staggered. 2 Standard Hooks 6-12 6. ÐÏ à¡± á> þÿ Q S Features technical data on mechanical splices including load tests for Type 1 and Also includes: development and lap splice length tables for welded wire reinforcement, expanded Sixth edition conforms to ACI 318-14 and AASHTO LRFD Bridge Design Specifications, 2016. 4 Lap splice lengths can be reduced if the lap splice is properly confined by transverse reinforcement per TMS 402. There are two types The key takeaways are that staggering lap splices reduces reinforcement congestion and bond stress concentration, improves structural behavior, and mitigates cracking. They are usually located in regions where larger inelastic deformation capacity can be expected, such as the base of RC walls and beam-column joints. lgpu dikiggc iebytvt vcvk iek gygzmp sltnspc sakn gwh nvrkqdti