shotcrete rebar spacing • ACI 304 Guide for Measuring,Mixing,Transporting and Placing Concrete. Cathodic protection & mitigation technologies. 15 Building Code Requirements for Structural Concrete (ACI 318-11) and Commentary First Printing August 2011 ISBN 978-0-87031-744-6 American Concrete Institute® top_reinforcement_layer_spacing and bottom_reinforcement_layer_spacing is the spacing between two consecutive reinforcement layers. Rebar Building Codes In Gunite & Shotcrete Pools The building codes for using rebar in Gunite Pools may vary from state to state and locality to locality. Wire tie Stay-Form to rebar every other rib. rebar stud design table for blind side walls 26 stay-form rebar sizing and wire-tie spacing 27 blind side wall form using stay-form 28 hook tie installation for blind side wall applications 29 box beam cavities 30 concrete footings 31 on grade steep slope slab 32 slab pocket 33 underwater piling repair 34 bar joist placement and fastening of Most projects benefit from the use of structural engineering plans that detail the grade, size, placement and spacing of rebar, along with the concrete coverage, strength and characteristics such as slump and additives. I can’t tell you what issues arise from such tight groupings, assuming they still get full concrete coverage, but that’s almost the norm. • ACI 506 Guide for Shotcrete. Additional design considerations may include: Shotcrete and Ground Support Early and long-term strength in ground support. Figure I'll make mats out of 3/8" that fit the curve of the form set one into the first 3-4" thickness that'll be cast on the ground, dunno if I should go 6 or 12" spacing on the long runs, probably just go 6" because "reasons", then the short direction I'll just have 4 runs, just enough to keep everything straight McKee Spacing Theory: = 3 𝜋𝑑2 4𝜎 Volume of one Fiber (V)= πd2L/4 Where d = Diameter L = Length Fiber Volume Fraction (σ) = Dosage (D) / Mass per Volume (M v) Spacing (S) = Overlap factor (O f) * L 𝐷= 𝑉 𝑣 𝑂𝑓 3 Should never be 1 since fibers are random. 8. underground metal mines in Canada (3). Ragland has 40 years of experience working on complex structural projects. Fiber suppliers should supply documentation from third party testing facilities that their fiber can meet the required joule specification using one of these tests. Additional bars can be placed at locations in the regular grid wherever required. The length of the lap varies depend on concrete strength, the rebar grade, size, and spacing. No. The maximum particle size of the stone shall not exceed 1/4 of the minimum dimension of the structural section, and shall not be greater than 3/4 of the net spacing of the steel. Fewer Materials. Mr. Other Components When making an addition or performing a major renovation on your existing pool, we highly recommend the use of gunite. drain matting is placed on the soil surface, followed by welded wire mesh and rebar whal-ers. • The height of the voids does not greatly influence the bond strength of a bar. High strength rebar is another material advancement addressed in 318–19. The reinforcing bars are allowed to be spaced at a distance of one fifth (1/5) of the lapped length to a maximum of 150 mm or 6 inches. The Shotcrete is hand finished and the form work removed to reveal a monolithic retaining wall. 5 cm to 7. 7. The installation of the rebar is critical for the success of the overall project. All vertical corners and termina-tions shall have port assemblies spaced 4 feet splices were able to develop nominal capacity with the bar spacing less than or equal to 4 in. The minimum spacing for noncontact lap splices as indicated in ACI 506. in areas where the span exceeds same mining limits. Crosswise of members: spaced evenly within 2 inches. Less than W or D4 Less than 12” 2-3 ft. It is critical the rebar be installed in a straight line so the rebar fits easily into the cavity between the polystyrene and the wire mesh. Concrete can have different properties depending upon the mixture that is used in creating it, which contains cement, chemical admixtures, and aggregates. Paragon's Rebar Support Chairs. 7–3 m and the bolt spacing is 1–1. A rigid facing (often pneumatically applied concrete, otherwise known as shotcrete) or isolated soil nail head plates may be used at the surface. ACI 318-08, Section 12. How is a bond beam made with SCIP panels? VCT is a concrete construction company specializing in commercial & industrial concrete corrosion, preservation & structural repair solutions. Legs spacing: 5". All vertical corners and terminations shall have port assemblies spaced 4 feet vertically, and Shotcrete. Expensive training is often required. Maximum control joint spacing is 20 times the wall section thickness. Lap Stay-Form sheets over a rebar support. W or D9 and larger Less than 12” 3-4 ft. n = number of bars being developed along the plane of splitting. (4) CODES: a. Taking into consideration the weight of the rebar structure, as well as the weight of the concrete, building a sturdy form is essential for any project. Therefore, in this study, considering the time-varying 1. Confirm that all field personnel have copies of authorized submittals. The New York State Building Code (NYSBC) and the International Building Code (IBC) both stipulate a #5 reinforcement bar maximum and 6-inch (152mm) minimum bar spacing. Take a guess. Once the vertical props are fixed, necessary joists are placed before laying the formwork sheets. tie load controls tie spacing. shotcrete. So it's entirely possible, and even likely, that any given pool will have an assortment of rebar at different spacings. One way to minimize these separations is to pin the two sections together with rebar. A high strength shotcrete mix is sprayed layer by layer to a thickness of 3” minimum. Specifying rebar geometry. c. To properly shotcrete this type of project with thick walls, heavy reinforcing bar sizes, and tight spacing requires using a qualified shotcrete contractor with a proper concrete mixture design, well-maintained and smoothly operating equip-ment, and a highly trained crew. Legs spacing: 2-1/2". Rebar that's too far apart lacks the tensile strength to reinforce the concrete sufficiently, but when it's too close, the cement in the slab won't mechanically bond to develop its own tensile strength. To modify a guideline definition of the distribution and direction of the reinforcing bars in rebar sets The spacing of the reinforcing bars is measured along the rebar set guideline. B. , including one portable and three fixed plants to service the San Antonio metropolitan area and surrounding markets. Tools and materials (listed left to right): woven polypropylene bags (about 18” x 30”), bucket chute (4-gallon bucket with bottom cut off), 4 or 5 heavy duty 2-gallon cement buckets, stringline, metal chisel and scrap steel for cutting barbed wire (or bolt cutters), hammer, sheetmetal slider (about 13” x 16”), 15 gauge galvanized wire, knife, wire cutters, tape measure, 4-point The panel is then set in place over the required tie-down and cemented in place. The bolt length is typically 2. Hoops and stirrups in special seismic systems used to support vertical reinforcing steel have a tighter specified spacing to prevent the vertical bars from buckling. Shotcrete reinforced with Nycon fibers conforms to the shape of your surface, meaning you’ll no longer need to use more than necessary to finish a job. Therefore, in this study, considering the time-varying The thickness of the concrete ceilings varies according to the weight it has to support, but it is usually between 5-6” for residential constructions. Typical bay spacing was 8ft (2. For this kind of specimen, the k value described in Fig. Specification for Shotcrete and Other Shotcrete Development ACI Spring 2012 Convention March 18 – 21, Dallas, TX ACI WEB SESSIONS Principal Ragland, Aderman & Associates, Inc. Applicators of structural wet mix shotcrete shall have a copy of ACI 506R-95 on each work site at the time of shotcreting. In reality, Shotcrete is an all-inclusive term used for describing the process of spraying concrete or mortar through either a wet or dry application technique. Structural wet mix shotcrete Concrete/Shotcrete Information. ” Soil is a primary determinant for a structural engineer’s placement of the rebar in his design, Benedetti says. The freeze-thawdurability of shotcrete is discussed in more detail later. 2, “Specification for Shotcrete,” is: “Clearance of at least three times the diameter of the largest reinforcing bar; three times the maximum size aggregate; or 2 in. 5 Results of the preconstruction testing program and a description of the proposed construction quality control Reinforcing bars (rebars) are an important component of concrete slabs, because they reinforce the cement and increase its load-bearing capacity. W. If you answered, a sprayed concrete, that would be incorrect. Shotcrete — Shotcrete – a special spray mix of concrete – is applied to the interior surface of the dome. Reinforcement details may complicate the use of shot-crete, but shotcrete is particularly cost effective where Spacing of transverse reinforcement shall not exceed 6 inches (152 mm). 2. ) Steel Yield Strength The use of rebar, strongbacks, walers, kickers, etc. 5 cm, or untensioned rockbolts at 1 m to 1. The freeze-thawdurability of shotcrete is discussed in more detail later. see detail a sizes and spacing preserve existing bars 1'-0" 2 3 existing concrete 8" shotcrete typical construction joint 8" channel lining 2x4 wood (remove before next placement) contractor shall clean overspray from reinforcing and subgrade prior to next placement of shotcrete minimum lap 8" per notes 4"± 2 12" 2 8" existing shotcrete 12" sawcut on existing Shotcrete voids were recreated using artificial voids made of silicone. The blind-side form for both of these systems must be left in place. After we have these very general numbers, we start playing w/ the design (size & spacing of rebar, mix & depth of conc. The concrete will be 6″ thick on 4″ of 2B stone. Very heavy and massive pieces of concrete will use heavier gauge rebar, but for typical driveway, sidewalk and step repair, ½-inch rebar is usually adequate. Use of synthetic and steel fiber reinforced shotcrete can increase the tensile strength of the shotcrete and provide the necessary ground support for a wide range of ground conditions. 12 GA. Blindside walls Bulkheads Bridges Shotcrete Retaining walls Keyways Ductbanks Tunnels Footings features & benefits • Reduced labor cost—no stripping costs (bracing only) • Lightweight sheets are easy to work with (install, cut, bend, etc. The lack of bond between shotcrete and underlying concrete Is Indicated by the large piece of shotcrete removed intact. We always define the rebar geometry with respect to a local coordinate system. 2) Member greater than 8 inches, but less than 2 feet deep: plus or minus 1/2 inch. If project drawings call for every second horizontal rebar to be cut at the control joints, cut rebar in line with the 5. Section 53 Shotcrete 4-5301 General. … read more. s = maximum center-to-center spacing (in) of transverse bars within l d. Preventing cracks in concrete is traditionally achieved with steel reinforcement and saw-cutting of joints. The contract C510 comprises the construction of two underground stations in sprayed concrete lining (SCL), Liverpool Street and Whitechapel. In most locations the ideal space between two adjacent rebars should be 2 1/2 inches. The SI unit of Mass is the Kilogram (Kg) which should be used for smaller The adjustable anchor requirements differ in that the maximum horizontal spacing is reduced to one anchor every 1. Perform additional required sampling and testing -2, Shotcrete – Structural Shotcrete . “Gunite” is a pneumatically applied concrete mixture reinforced with steel rebar. The stiffness of shotcrete in supporting structure is dynamic. The maximum misalignment of bed joints is 1. Subbase Information. 2. Another method uses a loop tie that is slipped through holes drilled in plywood, then hooked around rebar or rods. drain matting is placed on the soil surface, followed by welded wire mesh and rebar whal-ers. 2 Clearance. CRSI's Reinforcement Anchorage and Splices includes tables of required lap splice lengths based on these variables. 4 A list of the proposed shotcreting equipment, including brand name, model, and capacity of proposed pump and air compressor. If there is more than one layer of rebars the bars in the upper layers must be directly over those below them and no closer to them than one inch. 1 - When area of reinforcement provided is less than twice that required by analysis at splice location, length of overlap measured between outermost cross wires of each reinforcement sheet shall be not less than one spacing of cross wires plus 2 in. When the steel is dense, it can be poured with fine stone concrete. Solid concrete is normally removed around the perimeter of the spalled area, until at least 6" of clean, rust free rebar is exposed. Beam bolster . The rebar, or dowels, should be sized for the job. 2. Each rebar was 4 m long, with 1m protruding from the hole. For example, for a one-way solid slab with #5 temperature-shrinkage bars, high chairs are used at 4 feet on center; for #4 bars, high chairs would be placed 3 feet on center. ) o For 300 mm (12 in. 5 m. Also, The lack of a maximum of d/2 spacing on shear reinforcement as a minimum amount. 5 are permitted, there shall be a minimum clearance between parallel bars equal to six diameters of the bars used. 6. Shotcrete shall not be applied to spirally tied columns. 3 - Wall segments with a horizontal length-to-thickness ratio less than 2. The rebar diaphragm will be constructed on the slab and then hung via a crane on the Nelson Stud Nails. Shear walls can employ rebar in Grades 60 (420), 80 (550), or 100 (690). 5mm diameter can be used. The timber lagging is placed as the soil gets excavated in stages and then the rebar cage for the wall is placed with the wood lagging acting as a concrete form. The blower fans are shut off after the concrete is set. Extending Joint Spacing Reduce or eliminate cut joints. ). Horizontal lap 4-8” minimum* (see stud spacing chart on page 12) 5. It is sprayed onto the interior surface of the concrete dome, covering the polyurethane foam and mat of steel reinforcing bars. 3 of the 2015 International Building Code (2016 California Building Code). You're probably planning a Shotcrete or Gunite pond, but I bet you do not know what Shotcrete and Gunite are. Support should be installed before significant movement occurs. “The structural engineering will define the placement of the reinforcing steel within the wall, the spacing of the bars, the diameter of the bars and their schedule (or strength). Today, the rebar was delivered for the sub-grade structural wall. • International Code Council (ICC) ESR II65Report. ) walls, the maximum spacing remains 5 m (16 ft. Rib Spacing 8 GA. Recommended pour rate is 4’ to 7’ per hour. This is the reason Z can’t find any general formulas on the net for this design, it’s because UG is non-typical, it’s all custom and must be calculated out. shotcrete loading conditions. 0 8. The rebar in between should be spaced evenly, but the rebar placement should never exceed 18 inches from the next nearest bar. k-value. Typically, 10M (11. b. These re- quirements include #5 rebar as the maximum size of rebar to be used, a “6 inch” minimum rebar spacing and a prohibi- tion on the use of full contact lap splices. Designers over design the rebar and while it looks good on paper, realistically you don’t ever get the spacing required. 9 for more information). The Construction Manual contains policies and procedures related to the duties of Caltrans Division of Construction personnel, is for information only, and is intended as a resource for personnel engaged in contract administration. The unit weight and modulus of elasticity of good shotcrete are similar to that for conventional concrete. (610 to 914 mm) oc down the middle of the membrane. 150, 200mm, the rebar spacing in the opposite direction is generally 100, 150, 200, 300mm, up to 400mm. Shotcrete Support Design Good bond between rock and shotcrete • Direct Shear Failure unlikely • Adhesion Failure > 4m spacing Adhesive failure model (after Barrett and McCreath, 1993) 44 Typeequationhere. (64 mm) center-to-center spacing. 0” with Neighboring rebar be provided over a length equal to twice the member depth measured from the face of the supporting member. Hoops and stirrups in special seismic systems used to support vertical reinforcing steel have a tighter specified spacing to prevent the vertical bars from buckling. V. How-to checklist for swimming pool rebar and steel. Shotcrete can add significant strength to rock and should be used in long-term openings (ramps etc. Rebar is laid out and made into a 3D cage-like structure to support the gunite and give the cement its unique shape. Typical factor 0. A. W or D5 to W or D8 12” and greater 3-4 ft. , 4” o. The video shows the application of Shotcrete onto rebar. vi GENERAL NOTES 1. Slabs formed with common 2”x4” lumber are 3-1/2” thick. Installing Rebar It is common in swimming pool construction to lap slice reinforcing bar when a continuous bar is not feasible. Pavement Slab-on-Ground Composite Metal Deck Overlay Topping-Slab Precast Shotcrete . 9 ft (including 10 % Waste / Lap) There will be 8″ between each of the 5 pads to accomodate a row of brick pavers. Rebar being sprayed with Shot Crete for a Structural Wall When the steel bars are dense, choose the appropriate stones. Step 1. Very poor rock REBAR-BL-101 IN MIX NO. It is important to make sure the rebar is completely exposed so it becomes monolithically enclosed with the shotcrete or cement application. Many building inspectors have issued correction notices regarding the use of contact lap splices instead of non- contact lap splices in shotcrete and gunite construction in accordance with Section 1908. 4. 9. Pool rebar size/spacing from 3. Shotcrete – During the Course of Work: i. 5). CMD - thickness above the flutes. See Pile shoring plan view. Ltd. Shotcrete placement including verification of reinforcement prior to the placement of the shotcrete. 1. ) wall, space joints at no more than 5 m (16 ft. 6 in. 16. Shotcrete — Shotcrete – a special spray mix of concrete – is applied to the interior surface of the dome. The unit weight and modulus of elasticity of good shotcrete are similar to that for conventional concrete. Gunite is superior to alternative pool construction techniques such as vinyl liner or fiberglass pools in terms of structural strength and design options. 5 to 6 feet size 24 x 40 ft. The stiffness of shotcrete in supporting structure is dynamic. Current U. Used for underground 1. 3'-0' C/C 1236 843 4'-0' C/C 695 Shotcrete Mesh Panels D-Dome ™ Rebar Grouted rebar has also been proven successful for wall support using mainly resin or cement grout to anchor each bar into place. In lintels or concrete beams in EPS flooring systems, the shear stirrups can be eliminated or the spacing can be expanding to lower installation time and complexity. The rebar geometry can be constant or vary as a function of radial position in a cylindrical coordinate system. In this dialog we define the shotcrete facing parameters (thickness, rebar sizes, rebar spacings and materials), and we can also select a plate section for the soil nail head plates. Tools and materials (listed left to right): woven polypropylene bags (about 18” x 30”), bucket chute (4-gallon bucket with bottom cut off), 4 or 5 heavy duty 2-gallon cement buckets, stringline, metal chisel and scrap steel for cutting barbed wire (or bolt cutters), hammer, sheetmetal slider (about 13” x 16”), 15 gauge galvanized wire, knife, wire cutters, tape measure, 4-point The timber lagging is placed as the soil gets excavated in stages and then the rebar cage for the wall is placed with the wood lagging acting as a concrete form. <layer_spacing> 2. These practices can lead to many problems for concrete contractors and building owners. and 53-3, Shotcrete – Sculpted Shotcrete. Estimate how much rebar you need for your concrete slab on grade by entering the dimensions below along with the desired rebar spacing. It is important to make sure the rebar is completely exposed so it becomes monolithically enclosed with the shotcrete or cement application. 3 times the in Det. 01(1) Site Constraints Site constraints play a major role in decisions regarding guardrail selection and placement. The spacing of such reinforcement shall not exceed: (a) d/4, (b) 6 times the diameter of the smallest primary flexural rebar excluding longitudinal skin rebar, or (c) 6 inches. building codes limit rebar strength based on decades-old research, with most reinforcement used in concrete construction in the United States being Grade 60. Local building codes may vary, so determine the correct rebar spacing for your area and for your specific swimming pool project. Concrete Thickness. All applicable parts of ACI 506R-16 shall be followed. DIY gunite swimming pool construction 20 Shotcrete • Winter 2008 2. 5ld, nor 6 in. This section provides guidelines for inspection of shotcrete placement under Section 53, “Shotcrete,” of the Standard Specifications. concrete/shotcrete psi 3. thick or more. 5 mm) rebar is used in residential swimming pools, spas and water features. Applications of reinforcing bar support. Durable and long service life. Use 16-gauge tie wire or sheet metal screws The thickness of the concrete ceilings varies according to the weight it has to support, but it is usually between 5-6” for residential constructions. These are important properties for ground support applications. More technical info here: https://www. Taking into consideration the weight of the rebar structure, as well as the weight of the concrete, building a sturdy form is essential for any project. In order to remove these effects, a type of single-rebar slab specimen with a dimension of 600mm×500mm×200mm and a cover thickness of 30mm was adopted in the experiment as shown in Fig. The removal may have to extend further to accommodate lap splices, etc I request that the concrete be removed to an even depth of at least 1" behind the reinforcement, not 1" past the spalled concrete. 2” without Neighboring rebar correction 50 mm / 2. de C. The support stiffness of shotcrete is roughly calculated in engineering, which results in a waste of materials and increases the risk of construction. Maximum Joint Spacing. The next step is to set the vertical rebar with similar spacing. Shear wall nailing inspections when the nail spacing on the shear wall is 4 inches on center or closer. For an area of 15 square feet, you will need 2 bags per inch of placement. The south shoring wall bordered a residential property • Understand how compaction and proper encasement of rebar affect the quality of shotcrete • Understand hot and cold weather shotcrete placement • Understand the finishing process ASTM C1140 • Understand the scope and significance of use of practice • Know the allowable geometry and materials for test panel forms Many IBC shotcrete provisions were incorporated into 318-19 and, working with the American Shotcrete Association and ACI Committee 506, were updated to reflect current practice. However, there is a waiver provision in the Support Spacing on centers (inches) 24” 18” 12” Lateral Loading (psf) 1200 1200 1600 Liquid Head (feet) 8. Often shotcrete is used in conjunction with bolts to eliminate wire mesh and to permit wider bolt spacing (4). It is critical the rebar be installed in a straight line so the rebar fits easily into the cavity between the polystyrene and the wire mesh. CODES: 1. S. Rebar also helps measure the thickness of the shotcrete as it is applied. recent construction often having grade 60 rebar. 0 4. 0 10. S 2 S 1 S 1 >150 mm >6 ” S 1: 130 mm / 5. ) 2. This is the most effective way of creating a swimming pool from concrete. 5 m spacings, together with mesh-reinforced shotcrete applied to a thickness of 5 cm to 10 cm. At a maximum spacing of 120 inches (3048 mm). Shotcrete can be used instead of conventional concrete in many instances, the choice being based on convenience and cost. welded-wire mats cannot be used for shotcrete reinforcement. The rebar on each end of the section should be spaced 2 inches from the edge, with even spacing and no more than 18 inches between bars. ) • Easy rebar and conduit penetrations • Visual inspection of concrete pour and consolidation VCT is a concrete construction company specializing in commercial & industrial concrete corrosion, preservation & structural repair solutions. Wire tie Stay-Form to rebar every other rib. 5 bars, the 2 in. 5" clear to rebar, I recommended 2" min offset only when waterproofed. F. Minimum spacing between bars: minus 1/4 inch. The load carrying capacity is determined by the spacing and tensile properties of the steel, not the thickness of the concrete slab. W or D4 to W or D8 Less than 12” 2-3 ft. Transverse reinforcement shall be extended beyond the pier clear height for at least 12 inches (305 mm). 12. splices are 1. The diameter of the welded steel bar is 4-14mm, of which 0. 5 shall be designed as columns. All things considered, rebar is still the most appropriate option for the majority of industrial-scale concrete projects. Horizontal lap 4-8” minimum* (see stud spacing chart on page 12) 5. • Rebar congestion is significantly reduced, promoting more efficient inspection • Electronic spacing & recording • A minimum final shotcrete cover of 1 shotcrete matrix, result in a composite material that is ductile, tough and impact resistant. The circular bins share 2 to 3 common walls with adjacent bins. If the final facing consists of CIP or precast concrete, rebar mesh is typical. This project is an advanced shotcrete project. . The guys in the shop will usually add some extra horizontals or something to support all the bars that are left floating. 7. 19 Page 1610-3 September 2020 1610. Rebar should be placed evenly throughout the project. ACI Updated its Guide for Shotcrete Pros - The ACI CCS-4(20) April 5, 2021 Remove corrosion from metal and rebar without creating waste disposal difficulties. ) o For a 250 mm (10 in. The standard dose of fiber for shotcrete to replace wire mesh is 10lb of Nycon XL100 1. At the bottom of load-bearing walls or in the top of foundations where doweled to the wall; and 3. In Fig. 3. Shotcrete with added NaCl Conventional shotcrete Latex paint E and W faces Conventional shotcrete Latex paint and tie coat N face Latex paint E and W faces FIGURE 2 System 3: Removal of the shotcrete overcoat in 1985 ls shown. This is typically based on either direct calculation of section forces, or a requirement to match existing reinforcement. 3. Anytime you are using epoxy for either anchor bolts, hold downs, or rebar dowels. ) wall, space joints at no more than 4 m (13 f t. In lintels or concrete beams in EPS flooring systems, the shear stirrups can be eliminated or the spacing can be expanding to lower installation time and complexity. 21. D. where formwork cannot be used, 2. 5” long macro fibers per CY of shotcrete. PVC center bulb. 12. S. 3. 12 Requests made by the Public . , Consulting Engineers in Baton Rouge LA. Product manufacturers supply spacing tables based on the steel density ratio for each anode type. These codes also prohibit the use of full-contact lap splices. shotcrete faced soil nail walls for the following reasons: 1. Cathodic protection & mitigation technologies. 4. EcoAir The spacing of the form supports is as per the approved method statement or the as per the approved formwork drawings. 7. [2] Due to the large nature of the stope areas, it has been found that high horizontal stresses develop and cause deterioration of the development openings. Yields will vary with waste, uneven subgrade, etc. Helix has been used successfully in a number of high profile ICF projects (see case studies below) as well as in pre-cast, tilt-up, shotcrete, slab, and footings. This dramatically simplifies placing the bars in the field. When two curtains of steel are provided, the curtain nearer the nozzle shall have a minimum spacing equal to 12 bar diameters and the remaining curtain shall have a minimum spacing of six bar diameters. Woodlawn then embarked on a project to build a shotcrete machine capable of: complete. building Standards for the use of shotcrete as a structural component. pool rebar size/spacing for pool from 3. 6. Achieve early and long-term concrete strength in ground support with Master Builders Solutions' comprehensive products that allow durable sprayed concrete structures to be constructed successfully and safely. For accurate determination of the diameter, the spacing between the rebars must be greater than the limits shown in the drawing below with reference to the MC (4). Exact Spacing (Width) 16" Middle space 10" Total Bar Length 416. Building Code Requirements for Structural Concrete (ACI 318-11) and Commentary First Printing August 2011 ISBN 978-0-87031-744-6 American Concrete Institute® ASTM's cement and concrete standards are instrumental in the evaluation and testing of concrete, cement, and aggregates. Use 16-gauge tie wire or sheet metal screws where The core content of the convergence constraint method is to determine the reasonable support time and support stiffness. Rebar Spacing (in inches O. How-to checklist for swimming pool rebar and steel. 4m. 3 mm), 15M (16 mm) or 20M (19. W or D5 to W or D8 12” and greater 3-4 ft. 2. openings less than 6 m and between ½ and 1/3 for spans of 6 to 12 m. Each shotcrete nozzleman shall be qualified by constructing a 2 x 2-foot test panel fabricated to duplicate the project Shotcreting. These problems, in turn, allow water to migrate around and into a structure should the waterproofing system fail. A rebar cage for a drilled shaft is made up of longitudinal bars that are normally distributed with equal spacing around the outside of a cylinder. WisDOT Bridge Manual Chapter 14 – Retaining Walls July 2020 14-2 14. Recommended pour rate is 4’ to 7’ per hour. After application of the designed shotcrete facing, Suggested Support Spacing Welded Wire Reinforcement Range Welded Wire Spacing Suggested Support Spacing W or D9 and larger 12” and greater 4-6 ft. same rules as cast-in-place concrete, except the max allowed reinforcement is #5 rebar (not a constraint for most pool jobs). beginning work. Shotcrete is concrete that is pneumatically projected onto a surface. Features of reinforcing bar support. Suggested Support Spacing Welded Wire Reinforcement Range Welded Wire Spacing Suggested Support Spacing W or D9 and larger 12” and greater 4-6 ft. S. No vertical reinforcing steel was observed in the walls at the repair areas and at several other areas tested with a rebar detector. 1908. In this dialog we define the shotcrete facing parameters (thickness, rebar sizes, rebar spacings and materials), and we can also select a plate section for the soil nail head plates. Leveling of the formwork is also done before proceeding with the fixing of reinforcements. Often, both rebar and shotcrete contractors are required. 5 m and the horizontal spacing to 2 m. 10, you’ll The NYSBC includes requirements that need to be met to permit the installation of shot- crete as a structural component. The steel rebar is embedded in the concrete and when about three inches of shotcrete is applied, the Monolithic Dome is finished. c. If rebar locations are required in real time, a GPR survey can be used to A recognized authority in the shotcrete placement process, Drakeley has made it his mission to share what he knows about concrete science and application in an effort to help ensure a future defined by fewer structural failures and ultimately improve the industry’s performance and reputation. rebar, strongbacks, walers, kickers, etc. , select a rebar set and do any of the following: Shotcrete/Gunite Clearances 1. –Test panels permitted when rebar spacing limits in‐place cores Shotcrete(BC 1913) build safe | live safe 33 Define Shotcrete Facing and Head Plate Parameters Figure: Shotcrete and Head Plate Parameters in the SnailPlus Wizard. (50 mm) minimum probably controls and would then provide a 2. I. Cemex has closed on the assets of Texas’ Beck Readymix Concrete Co. Shotcrete with a measured air content of 6% may provide a spacing factor above 300 µm (0. • The optimal combination between the consistency and the airflow rate must be sought. Depending on your choice of decking (plain, exposed aggregate, pavers or stamped, sundek, stone, travertine etc. Shotcrete may only be applied to tied columns where the spacing of the reinforcing steel is the same as for walls. 5 to 6 feet size 24 x 40 ft. Skill level: It takes an experienced nozzle operator to spray shotcrete effectively so the reinforcing steel is fully encased by the shotcrete. Joint Spacing. , nor less than 1. 3. For a flat slab, such as a driveway, consider placing the rebar in an 18 inch grid spacing, keeping the edge rebar at the same distance from each side. If the % steel required by stress analysis is less than 200/F y, the minimum of (200/F y-or- 1. In the future, the IBC will reference ACI standards to govern the use of shotcrete. W or D4 to W or D8 Less than 12” 2-3 ft. 0 7. Rebar & Heavy WWF Sheets Temperature/ Shrinkage 2. ) to reach the final design eg; the sweet spot of strength vs cost. It is important to make sure the rebar is completely exposed so it becomes monolithically enclosed with the shotcrete or cement application. Class B based on the development lengths These bar laps Chapter 1610 Traffic Barriers WSDOT Design Manual M 22-01. Reinforcement at the top and bottom of openings, where used in determining the maximum spacing specified in Item 3 above, shall be continuous in the wall. 1. 77 square feet, and the vertical spacing to a maximum of 16 inches. Transverse reinforcing is placed around and attached to the longitudinal bars, with the longitudinal and transverse steel being held together with ties, clamps, or, in special cases, with welds. To compensate for this imbalance in concrete’s behavior, rebar is cast into it to carry the tensile loads. c. Concrete - Shotcrete is a special high strength mix of concrete. The specific reason for the increase of bearing capacity is that the core part of the concrete has a large transverse deformation, so that the spiral stirrups produce ring tension, that is, the core part of the concrete by the radial pressure of the spiral tendons, in the three-way pressure state, Pressure strength can be used spiral stirrup or Finishing Shotcrete as final face. org/pages/products-services/shotcrete-resources. ), which will not be sufficient to ensure long term durability. There is not an accepted analytical model that can properly identify the restraint induced by soil nail connections, and therefore, the temperature or shrinkage cracks cannot be The core content of the convergence constraint method is to determine the reasonable support time and support stiffness. 25 inch, the clearance between the connecting parts cannot exceed 1/16 inch and the pintle ties must be 3/16 inch diameter. When bars larger than No. The top and bottom layer of injection port assemblies shall be two feet in spacing, located one foot from the edge of the membrane. They then "lift" the entire steel mesh up off the ground and off the walls by 3 inches using small concrete spacers, so that when they shoot the shotcrete, the rebar will ride in the center of the 6 inch shotcrete shell. Front face of concrete wall should line up with front face of shotcrete wall. Where the column spacing is not on a regular, symmetric grid, the layout of the reinforcing bars in the mat should be placed on an orthogonal grid and should not be skewed to follow the column layout. This assumes that the concrete will contain aggregate that is no more than three-fourths of these distances; otherwise the aggregate size or bar spacing must be changed. htm. 45 Steel Support Interlocking Lagging Load Capacities in P. Extending the blockouts and adding transverse bars underneath the splices did not add to the capacity. Strong support and good stability. Used for building foundation. Spacing should be approximately ½ the dowel length. e. Come on. As Conco Reinforcing owns and operates two state-of-the-art rebar fabrication facilities, it provides us with the resources and expertise to be the single source for all of your reinforcement and installation Bolts spacing is mainly bases on Ø20 mm E = Energy absorption in fibre reinforced sprayed concrete ESR = Excavation Support Ratio Areas with dashed lines have no empirical data Support categories RRS - spacing related to Q-value Si30/6 Ø16 - Ø20 (span 10 m) D40/6 + 2 Ø16 - 20 (span 20 m) Si35/6 Ø16 - 20 (span 5 m) D45/6+2 Ø16 - 20 (span 10 m) Shotcrete Support Design Poor bond between rock and shotcrete • Direct Shear Failure unlikely • Adhesion Failure > 2. (location, size and spacing) is similar to that for conventional forming methods per ACI 347, Guide to Formwork for Concrete. The shotcrete pillars were constructed by forming a square cage of rebar anchored in boreholes in both the floor and the back (Fig. Concrete Mix can be used for building or repairing foundation walls, sidewalks, curbs, steps and ramps and for setting posts. Possible reinforcement includes vertical rebar within the masonry unit cells, horizontal bond or lintel beams, and/or horizontal joint reinforcement. 1 is 4. Shotcrete is used for facing of soil nail walls. ). Less than W or D4 Less than 12” 2-3 ft. b. * 6. The bases can be pre-fabricated on surface and the shotcrete is sprayed on a mesh frame for reinforcement. Additional rebar was tie-wrapped to this rebar to complete the cage. So, if you are building a floor, wall, or any load-bearing structure, then rebar would be a solid reinforcing option. Shotcrete, a method of placing concrete by projecting it at high velocity, was not explicitly discussed in previous versions of ACI 318 but is now specifically included in ACI 318-19. 5. 1. • UL® Approvals for use as an alternate or in addition to welded wire fabric used in floor-ceiling D700,D800 and D900 series designs. If this is the case, you will need 8 bags. Installed 964 soil nails & 42 tiebacks for riverboat facility. Rebar also helps move the temperature around in the concrete, mitigating the stresses created by uneven temperatures and shrinkage in the concrete. Step 1. Typically, the spacing of the rebar is (24") on center. The surface retaining liners are usually steel-fibre-reinforced shotcrete, but in burst-prone conditions, wire meshes are laid on the top of the steel-fibre-reinforced shotcrete. PINKBAR™ Fiberglas™ Rebar for Flatwork is a superior reinforcement material for concrete flatwork applications including parking lots, sidewalks, patios, pool decks and driveways. Licensed Professional Engineer in eight states. proposed rebar is #3 at 8 inch spacing with 10 inch sidewalls 6 - 8 inch floor. Corrosion and rust resistant. The rebar chair 10 supports the reinforcing steel with a predetermined minimum spacing from a closed side of the form 14, thereby assuring a predetermined minimum concrete wall thickness between the steel and an outboard side of the concrete shell structure 16. The rebar is used to reinforce the shotcrete facing around the anchors to increase resistance to punching shear forces. 1. to act independently. Shotcrete applied to a thickness of 2. Various sizes for choice. Do not vibrate previous lift by more than 6”. Most cases the wall is actually a shotcrete wall where concrete is pumped by a hose. the use of 75 ksi rebar is allowed to assist in meeting the seismic transverse reinforcement detailing requirements when required in Seismic Zone 1 (see Section 5. It is critical the rebar be installed in a straight line so the rebar fits easily into the cavity between the polystyrene and the wire mesh. When No. 333 * bending percentage required) is calculated and compared with the Minimum Temperature & Shrinkage A s % entered here, and the greater of the two is used to calculate rebar spacing requirements. 8. 2m) as the existing grade rose. The second is the spacing between neighboring bars. Shotcrete may only be applied to tied columns where the spacing of the reinforcing steel is the same as for walls. 3) Members 2 feet or more deep: plus or minus 1 inch. 5 bars; There shall be a minimum clearance between parallel reinforcement bars of 2 1/2 inches; Bars larger then # 5 increase the chances of shadowing (voids behind rebar) Steel bars placement should be at the size & spacing defined in the strutural plan. SPECIFICATION CLAUSE 5. The maximum joint spacing for shotcrete is 20 times the wall section thickness to a maximum of 16 feet (5 m). For each additional 300 mm (1 ft) shotcrete thickness, one additional rebar mat was installed. , whichever is least”. A few things, not done correctly, size of rebar, spacing of rebar, the amount of rebar, lack of inner core, and outer core concept, the shear tie hoops and not visible. ld shall be the development length for the specified yield strength fy in accordance with 12. Because of this, the Building Code places limitations on the size and spacing of rebar in gunite & shotcrete. Lap Stay-Form sheets over a rebar support. Quikrete 80 lb. The structural section is small. Minimum Requirement for Lap Splice Length Both types of lap splices have a minimum splice length requirement as follows: Lapped Splices for Multiple Concrete Pours shotcrete shapes (vis-a-vis no need for minimum rebar cover), and a potential for faster buildup due to the cohesive effect fibers have on fresh shotcrete (assuming the fibers are not wasted in shotcrete at Woodlawn resulted in significant improvements in ease of application. This staggered pattern of horizontal reinforcement is necessary to allow for the vertical reinforcement to be placed from the top and weave in between the horizontal steel bars. Place shotcrete as normal following ACI 506R – Guide to Shotcrete I run into this a lot in the shop where I specify lap splicing between bars of difference spacing on center. The steel rebar is embedded in the concrete and when about three inches of shotcrete is applied, the Monolithic Dome is finished. E. APPLICATIONS Shotcrete can be cost-effective 1. The rebar needs to be correctly spaced, however. Most cases the wall is actually a shotcrete wall where concrete is pumped by a hose. REBAR-DL-101. When about three inches of shotcrete is applied, the self-supporting shell of the monolithic concrete dome structure is finished. C. Mesh and straps Design of post-installed reinforcing barconnections requires that the type, size, spacing and quantity and anchorage / splice length be established for the connection. Steel bars should not be exposed anywhere in the pool encasement. ) the concrete must be poured into place first. The length of the reinforcements and their tension depend on the geotechnical conditions and wall geometry. Once the diaphragm is securely anchored, the shotcrete will be applied to what will then become the structural wall. The walls are 7 inches thick and are reinforced with #5 horizontal hoop steel placed at 8 to 14 inches on center. Vertical lap (2 ribs minimum) 4. The injection port assembly spacing shall be 4 feet in any direction with 2 feet offset every vertical step. d. , Monterrey, Mexico; CP staff. Existing project drawings or specifications may be available to provide some of the information necessary but they Define Shotcrete Facing and Head Plate Parameters Figure: Shotcrete and Head Plate Parameters in the SnailPlus Wizard. 0 Maximum Defl ection (in) 1-1/4 3/4 1/8 Recommended Lap (inches vertically 86 4 Recommended Ties at Lap (both ribs horizontally 22 1 1 One should not be confused between air ontent and spacing factor, as adequate air contents do not necessarily guarantee an adequate spacing factor. 0 Pour Rate (feet/hour) 4. (610 to 914 mm) oc down With the geote tile side facing towards the shotcrete placement, attach the membrane to the substrate with staples, approved by GCP, spaced at 24 to 36 in. Following the engineer’s design, they constructed a 12-inch-by-12-inch grid of #4 rebar throughout what would be the new wall. Vertical lap (2 ribs minimum) 4. where formwork cannot be used, 2. 19. The spaced stiffening elements reduce the local buckling length of the bars, assure a high normal and bending moment resistance and secures a transfer of lateral forces in the lining before the shotcrete has reached its design strength. APPLICATIONS Shotcrete can be cost-effective 1. 8’ high wall in the table is not •Shotcrete •Walls •White Topping Advantages: UltraFiber 500® provides excellent secondary reinforcement from high fiber surface area, close fiber spacing, excellent bonding within the cement matrix, high fiber tensile strength, and easy dispersion in concrete so it is always positioned correctly. forcing steel and closer joint spacing are used to control shrinkage cracking. 2. Considering the transportation conditions, the length of the welded wire should not exceed 12m and the width should not exceed 3. long. The rebar embedded was 550mm long and 19mm in diameter. For example, shotcrete use can lead to voids in concrete walls and behind rebar. Figure 6. • A void’s transversal length of approximately 20% sets a bond performance threshold. Meanwhile, DIYers will find wire mesh to be a more useful option given its overall ease of application. . Spacing of bar supports depends upon the size of the reinforcing bar being supported. After application of the designed shotcrete facing, be provided over a length equal to twice the member depth measured from the face of the supporting member. Spacing for Euclid’s Labor: Installation of reinforcing steel and application of shotcrete are two separate operations. where • Rebar congestion is significantly reduced, promoting more efficient inspection • Electronic spacing & recording • A minimum final shotcrete cover of 1 Rebar Calculator Processing . 2. where As the knowledge, testing and experience of using fiber-reinforced concrete continues to grow for concrete applications, their successful use and benefits are now being fully realized through projects including floor systems, precast concrete, walls, shotcrete, and pavement systems. Larger domes have more inches of concrete and larger diameter rebar, all of which are specified by our engineers during the design phase of your project. spacing s and that crosses the potential plane of splitting through the rebar being developed. Sono tubes were originally used as forms, but these were found to bulge too easily. 012 in. * 6. For blind-side forms that need to be stripped, use taper ties and a back-side form of plywood sheeting with flat vertical studs If the final facing consists of shotcrete, the reinforcement in the final facing is similar to that described for shotcrete in the initial facing. Shotcrete wall should be 2” in front of I beam. 25 m spacing (after Barrett and McCreath, 1993) 45 forcing steel and closer joint spacing are used to control shrinkage cracking. 3. Steel density ratios based on rebar spacing have been calculated for rebar sizes 5, 6, and 7 bars and are located in the appendix of this module. The maximum size of reinforcement shall be No. W or D9 and larger Less than 12” 3-4 ft. 8. 5 or smaller bars are used, there shall be a minimum clearance between parallel reinforcement bars of 2 1 / 2 inches (64 mm). About Press Copyright Contact us Creators Advertise Developers Terms Privacy Policy & Safety How YouTube works Test new features Press Copyright Contact us Creators Once the shotcrete form was in place, the crew drilled into the top of the concrete garage walls and epoxied reinforcing steel into the holes at 12-inch-on-center spacing. RE: Rebar Dowel Size and Spacing hokie66 (Structural) 18 May 09 18:18 If your piping installation has disturbed the ground sufficiently that settlement could be a problem, then the engineer may want to thicken the slab enough to install a bottom layer of reinforcing so that the slab spans across. 4. o For a 200 mm (8 in. Each soil nail connection to the shotcrete face restrains the concrete from temperature or shrinkage movement. In each case, you must specify the spacing, s, and the angular orientation, α, of the rebar with respect to this local system. e. Karl from Shot tech here in Perth, is shown in the following video. Submit survey request if needed. have been tested and approved by the Iowa Department of Transportation, office of materials division, and either meet or exceed the load carrying capacity of steel supports and can therefore be used at the same spacing as wire supports. The SI unit of millimeter should be used to convert inches to millimeters. 3 (3500 P. Installation Recommendations: • The Stay-Form ribs face into the concrete pour • 4”-8” minimum lap between running Stay-Form sheets Rebar mapping surveys can determine rebar distribution (spacing and depth of the different rebar layers), rebar cover thickness, overall concrete slab thickness, and detect any other features within concrete including post tension cables, conduits, ducts, and voids. and the blockout between 17 and 20 in. exposed structure faces can be 1. LATTICE GIRDERS/ 4 BARS. The fourth course is placed in the same position as the second. Shotcrete pillars Shotcrete pillars are used in the same manner as rock pillars, i. It became obvious that a wet shotcrete system was a solution for the difficult Woodlawn ground, but the high capital and operating cost of applying shotcrete needed to be addressed. Soil Nail Case Study Tunica Riverfront Park Tunica County, Mississippi. c. Height::1" to 5" in 1/4" increments. Possible values: 1. Helix has been used successfully in a number of high profile ICF projects (see case studies below) as well as in pre-cast, tilt-up, shotcrete, slab, and footings. Per the California building code, a Shearwall Nailing Inspection by a Deputy Inspector is required to verify the shear wall construction of all wood shear walls where the required nail spacing is 4” on center or less (2” o. Sources: Cemex S. The versatility of bypass shotcrete allowed the bay size to be modified from classical timber lagging spacing and maximize the capacity of the bypass connection. minimum rebar spacing: 10 inches x 10 inches (on center) pool beam thickness: 12 inches x 12 inches. size/spacing of the steel –including the number of layers dosage SLAB ON GROUND. A lap is when two pieces of reinforcing bar (rebar) are overlapped to create a continuous line of rebar. In your case with No. below grade and above grade applications using 8" respectively. The main difference with shotcrete pillars is that they are engineered for the specific situation. Special moment frames can use Grades 60 (420) or 80 (550). c. 4. Toughness of shotcrete is a very important criterion because it may prevent an uncontrolled failure after initial cracking of the shotcrete lining associated with deformation of the rock. The rebar is used to reinforce the shotcrete facing around the anchors to increase resistance to punching shear forces. K tr = 0 can be used for a design simplification. The STAY-FORM ® ribs face into the concrete pour 4”-8” minimum lap between running STAY-FORM ® sheets 2-rib minimum lap between stacked STAY-FORM ® sheets Rebar is once again, added for extra strength, it is actually dowelled into the gunite shell at points around the pool perimeter. ) CONCRETE GRADE 60 REINFORCING STEEL BAR LAP DIMENSIONS FOR R E B A R-B A R L A P 1 1 provided is at least twice that (a) the area of reinforcement Class A splices may be used when development length. (location, size and spacing) is similar to that for conventional forming methods per ACI 347, Guide to Formwork for Concrete. The spacing of such reinforcement shall not exceed: (a) d/4, (b) 6 times the diameter of the smallest primary flexural rebar excluding longitudinal skin rebar, or (c) 6 inches. of the soil nailing for the execution project, the vertical spacing between two horizontal rows of reinforcements was taken equal to 1. Show 2” clear on plan view between shotcrete and I beam in the shoring wall detail. , 3”o. The rebar set guideline can be a line, or a polyline that may have corner chamfers. Shotcrete offers advantages over conventional concrete in a variety of new construction and repair work. (<spacing in layer1 and layer2>, <spacing in layer2 and layer3>, ) and number of elements of tuple must be equal to one less than number of layers. Reinforcement shall be placed in the panel to provide a minimum 1 inch (front and rear) embedment and be of the same size and spacing encountered in the structure. The shotcrete placement can properly encase the reinforcement given the reinforcement design (size, spacing, and amount) The material meets the project specifications The finish will meet the owner's expectations The pre-construction mockup panels should represent the most difficult-to-shoot part of the proposed project. For a patio you can use a grid spacing of 24 inches. Based on the absolute priority of health and safety during all construction phases and structural demands it became necessary to spray reinforced shotcrete with bar diameters up to 32 mm. Where shotcrete reached or exceeded 100 mm thickness, the contractor installed a Q188 rebar mat (6 mm (~1/4”) bar diameter at 150 mm (6”) spacing in both directions), attached to the rock anchors. Essentially, provide contact lap splices more for the guys tying the rebar than for strength. This mix designed for pouring concrete 2 in. Shotcrete walls are constructed in a similar way as cast in place walls but instead of constructing the second side of the form work a special type of concrete, Shotcrete, is then blown onto the single sided form. Anodes are estimated to provide 5 to 15 years of corrosion protection. The size of the rebar, the slump of the concrete, the location of the rebar, the spacing of the rebar the size and grade of the reabar are placed in the pool so it is structurally sound. ASTM C1550 Shotcrete round panel test Fiber Terminology Mono-filament fibers: a single fiber, which may not be prismatic in cross-section. The top and bottom layer of injection port assemblies shall be two feet in spacing, located one foot from the edge of the membrane. Click here for Specification Chart. Call out rebar and spacing in the retaining wall detail. According to NCMA TEK 10-3 (2003), Table 2 (Maximum Spacing of Horizontal Reinforcement to Meet the Criteria As > 0. Do not vibrate previous lift by more than 6”. The injection port assembly spacing shall be 4 feet in any direction with 2 feet offset every vertical step. Water migration can derail timely project completion at great cost, while exposing the structure to leaks and flooding over its useful life. Applicable parts of ACI 506R-95 shall be followed. 0007 An) for un-grouted or partially grouted walls vertical spacing of wire is 16 inches on center for eight- and 12-inch block. Compression Strength (f'c) MPa. 4m) but was reduced to 7ft (2. The support stiffness of shotcrete is roughly calculated in engineering, which results in a waste of materials and increases the risk of construction. Proper rebar spacing is important to the structural strength of the swimming pool foundation. In places where this is the primary purpose for the rebar, it’s referred to as temperature steel. Rebar Accessories & Equipment; Consult manufacturers' literature for maximum chair and other support spacing and use a 12-inch minimum reinforcement spacing so workers can avoid walking on the Bars installed using drilling techniques are usually fully grouted and installed at a slight downward inclination with bars installed at regularly spaced points across the slope face. d. Another option for placing the rebar in the concrete slab is to drill the concrete slab and pour epoxy in the cavity placing the rebar within its confines. Top bars in slabs and beams: 1) Member 8 inches deep or less: plus or minus 1/4 inch. With the geote tile side facing towards the shotcrete placement, attach the membrane to the substrate with staples, approved by GCP, spaced at 24 to 36 in. shotcrete rebar spacing