ACI 315R-2018 Guide To Presenting Reinforcing Steel Design .

-GUIDE TO PRESENTING REINFORCING STEEL DESIGN DETAILS (ACI 315.1 R 18)25.7-Slabs, p. 43CHAPTER 6-REVIEW OF PLACING DRAWINGS,p. 4 66. 1-Scope, p. 466.2-Definition, p. 466.3-0verview, p. 466.4-Procedure, p. 466.5-Review of placing drawings, p. 486.6-Levels of approval, p. 49!c'hCHAPTER 7-R EFERENCES, p. 49Authored documents, p. 50CHAPTER 1 -INTRODUCTION AND SCOPE1.1-lntroductionThe purpose of this document is to guide the licenseddesign professional (LDP) in determining the informationa reinforcing steel detailer requires to properly prepare rein forcing steel fabrication details and placing drawings. Guid ance to the LDP is provided on how to present that informa tion qn their structural drawings so that the design intent iseffectively and accurately conveyed.The intent of this guide is to encourage clarity and consis tency in reinforcing steel design details to help improvethe q11ality and uniformity of steel reinforcement detailing,fabrication, and installation. It is intended to facilitate clearcommunication between LDPs, reinforcing steel detailers,fabricators, and placers by encouraging clear presentationof design details and information. Information presented isconsistent with the requirements and recommendations ofseveral ACI documents, including ACI 3 1 8, ACI 3 0 1 , ACI1 1 7, ACI 1 3 1 . 1 R, and ACI 1 32R. nominal maximum size of coarse aggregate, in. (mm)nominal diameter of bar or wire, in. (mm)specified compressive strength of concrete, psi(MPa)specified yield strength for nonprestressed rein forcement, psi (MPa)overall thickness, height, or depth of member, in.(mm)development length in tension of deformed bar,deformed wire, or plain and deformed welded wirereinforcement, in. (mm)development length in tension of deformed bar ordeformed wire with a standard hook, measuredfrom outside end of hook, point oftangency, towardcritical section, in. (mm)straight extension at the end of a standard hook, in.(mm)factored shear force1.2-ScopeThis guide provides general and specific information, aswell as illustrative design details that are required for steel reinforced concrete members such as slabs, beams, andcolumns. The importance of this information is emphasizedto ensure that the reinforcing steel detailer effectively andaccurately captures the intent of the LDP, and presents it in amanner that is clear and unambiguous to the reinforcing steelfabricator and placer. Recommendations are also providedconcerning the review of placing drawings by the LDP.2.2-Defi n itionsACI provides a comprehensive list of definitions throughan online resource, ACI Concrete Terminology. The defini tions provided herein complement that resource.design details-drawings or other information presentedby the licensed design professional (LDP) defining steelreinforcement sizes, locations, clearances, splices, geom etry, points of termination, relationships, and tolerances.detailer-person, firm, or corporation producing the rein forcing steel fabrication details and placing drawings basedon the design drawings and design details for the structure.detailing-the process of determining fabrication detailsbased on design details.fabrication details-dimensions and geometry of steelreinforcement determined for fabrication.fabricator-person, firm, or corporation producing thereinforcing steel cut and bent to needed dimensions andgeometry.federated model-a building information model (BIM)that electronically links, but does not merge, single-disci pline models together for analysis or presentation; the modeldatabases remain distinct and are not combined into a singledatabase.placing drawings-detailed drawings that give the quan tity, size, dimensions, spacing, locations, and other informa tion required for reinforcement fabrication and installation.CHAPTER 2-NOTATION AND DEFINITIONSCHAPTER 3-GENERAL CONSIDERATIONS2.1-Notationgross area of concrete section, in.2 (mm2) where fora hollow section, Ag is the area of the concrete onlyand does not include the area of the void(s)A 51total area of nonprestressed longitudinal reinforce ment, including bars or steel shapes and excludingprestressing reinforcement, in.2 (mm2)bwidth of member, in. (mm)ddistance from extreme compression fiber to centroidof tension reinforcement, in. (mm)3. 1-Bui lding information modeling (BIM)3.1.1Introduction to ElM-Building informationmodeling is a three-dimensional process used to generateand manage digital models of buildings and other structures.This process is used by those who plan, design, and buildstructures, as well as those who manage these facilities. Theprocess involves creating and maintaining intelligent modelswith attributes that represent characteristics of a facility andcontain parametric data about the elements within the model.Many software packages exist that fall within the definitionAg American Co ete InsLicensee Chongqing Institute of quality and StandardizationbProvided by I ftQJn license with ACIAmerican Concrete Institute - Copyright @ fMate'l'laf5LHW oncrete.orgNo reproduction or mg permitted without license from IHSr5990390

GUIDE TO PRESENTING REINFORCING STEEL DESIGN DETAILS (ACI 315.1 R-18)of BIM; each of these have distinct advantages to varyingelements of the life cycle of a facility, from its design toconstruction through operation.Although the focus of most BIM discussions center on thethree-dimensional virtual model, the parametric data is ofequal importance. The following is from the National BIMStandard-United States"' (NBIMS-USTM 20 1 5):Building Information Model: Is the DIGITALREPRESENTATION of physical and functionalcharacteristics of a facility. As such it serves as ashared knowledge resource for information abouta facility, forming a reliable basis for decisionsduring its life cycle from inception onwards.In general, what makes BIM different than simple three dimensional modeling is more information; not only is it avirtual mockup of a structure, but also a relational databaseof information.A building information model is applied to the details ofconcrete reinforcement in the design and construction phasesof a structure. In the design phase, BIM is often used bythe design team to define the physical characteristics of theconcrete to be reinforced by defining concrete edges in phys ical space, and reinforcement information using either datawithin the concrete elements or physical representations ofthe reinforcement. During the construction phase, concretegeometry is often further developed to the level required forconstruction, and reinforcement is defined to a level fromwhich it can be fabricated and installed. The definition of thelevel of modeling, which is known as the Level of Develop ment (LOD), is a key concept described as follows.3.1.2 Level ofDevelopment-The content and reliability ofa BIM is defined by an industry standard referred to as theLevel of Development (LOD). The American Institute ofArchitects (AlA) and BIMForum have developed an LODspecification (20 1 6) to standardize these definitions. Thespecification enables BIM stakeholders to specify and discusswith precision the content and reliability of models at differentstages of the design and construction process. The LOD speci fication incorporates the AlA definition from the AlA G202"'20 13 form and is organized in The Construction Specifica tions Institute (CSI) UniFormafM (20 1 0), which defines theimportant properties of model elements at various levels ofdevelopment. This establishes a framework that allows modelcreators and users to establish reliable uses for the model. Theintent of the specification is strictly to facilitate communi cation; it does not establish or prescribe what LOD is to beattained at any specific point in the project.For example, in the construction phase, the concrete geom etry is defined to a construction level of at least LOD 3 00 or3 50, and the reinforcement is defined to LOD 350 to 400 toassure proper fabrication and placement (CSI UniFormat"'20 1 0). Many structural design models produced are not ableto provide this level of detail for reinforcing steel.3.1.3 Benefits and challenges ofBIM-The technology ofbuilding construction and the preparation of documents forconstruction is rapidly evolving. AU stakeholders s·hould beAmerican Concrete InstituteProvided by IHS Markit under license with ACINo reproduction or networking permitted without license from IHS3aware of the potential benefits and wary of potential chal lenges in using new or evolving technology.Licensed design professionals who are using BIM will,in most cases, be focused on developing models for theprimary purpose of design rather than construction. Conse quently, downstream users of design models should be warythat the information found in them might not be developedto the level required for their purposes.The benefits of BIM accrue at all stages of a project to allstakeholders, including the owner, owner's representative,construction manager, contractors, subcontractors, materialand equipment suppliers, and designers. The manner ofBIMimplementation can be tailored to the nature of the project,nature of the owner, delivery method, and delivery timeavailable. Potential benefits include:3.1.3.1 Design and detailinga) B etter visualization, especially when dealing withcomplex structuresb) Improved coordination between trades through infor mation sharing, which is one goal of a BIM processc) Ability to rapidly compare alternativesd) Improved communications and efficiency and reducederrors through:1 ) Detecting and addressing issues earlier in the designprocess, thereby reducing the number of requests for infor mation (RFis) and issues in the field2) Clearer communication of structural geometry anddesign intent from the LDP to the reinforcement detailerthan what would be possible using traditional two-dimen sional documents3) Reinforcing details presented in three dimensions at aconstruction LOD4) Better communication of reinforcement fabrication andplacement information with downstream entities3.1.3.2 Construction-Enhanced project visualizationmade possible by having full building models and relatedinformation readily availablea) More accurate material takeoffs, leading to less wasteand reduced overall project costsb) Improved project coordination, clash detection, andresolution achieved by combining three-dimensional modelsfrom various subcontractors into a single federated modelc) Validate the work sequence or progress with four dimensional models created by the intelligent linking ofindividual three-dimensional components or assemblieswith time- or schedule-related informationd) Increased change management so stakeholders betterunderstand the impacts associated with them3.1.3.3 Operationa) Better 'as-built' documentation than conventional two dimensional drawings, leading to easier remodels, rebuilds,and additionsb) Improved management of a building's life cycleachieved by using the three-dimensional model as a centraldatabase of all the building's systems and componentsc) Enhanced tracking of building performance and main tenance needsLicensee Chongqing Institute of quality and Standardizationb5990390American Concrete Institute - Copytri!!l flt .@1Ma af os www.concrete.org

4-GUIDE TO PRESENTING REINFORCING STEEL DESIGN DETAILS (ACI 315.1 R 18)3.1.4 IFC files and BIM file transfers-Numerous BIMsoftware packages exist that can define concrete geometryand data, detailing reinforcement, or both. Most BIM soft ware is compatible with an open file format specificationknown as the Industry Foundation Classes (IFC) data models(ISO 1 6739:20 1 3). This is an object-based file format thatallows ease of interoperability between software platforms.Industry Foundation Classes files can be exported from,and imported into, most BIM software platforms, allowingmodel content and data created in different software to beviewed and used in other software.In addition to IFC data file transfers, which can be broughtdirectly into a building information model, there are manyother electronic deliverable formats available for conveyingmodel content to other stakeholders. Many programsshare information-rich models securely, accurately, and ina relevant context that can be viewed on a variety of plat forms-from desktop computers to hand-held tablets andsmartphones. There are also various types of two- and three dimensional PDF documents that can be used.3.1.5 State of the technology-Building informationmodeling began in the late 1 990s. One characteristic thatmakes BIM superior to past technologies is the ability tochange and evolve with newly developing technologies thatare providing an ever-i

the q11ality and uniformity of steel reinforcement detailing, fab rication, and installation. It is intended to fac ilitate clear communication between LDPs, reinforcing steel detailers, fab ricators, and placers by encouraging clear presentation of design details and information. .