1、ACI 313-97 was adopted as a standard of the American Concrete Institute on January7, 1997, to supersede ACI 313-91, in accordance with the Institutes standardizationprocedures.Copyright 1998, American Concrete Institute.All rights reserved including rights of reproduction and use in any form or by a
2、nymeans, including the making of copies by any photo process, or by electronic ormechanical device, printed, written, or oral, or recording for sound or visual reproductionor for use in any knowledge or retrieval system or device, unless permission in writing isobtained from the copyright proprietor
3、s.This standard was submitted to letter ballot of the committeeand was approved in accordance with Institute standardizationprocedures.313-1This ACI standard practice gives material, design, and constructionrequirements for concrete silos, stave silos, and stacking tubes for storinggranular material
4、s. It includes design and construction recommendations forcast-in-place or precast and conventionally reinforced or post-tensioned silos.Silos and stacking tubes are special structures, posing special problemsnot encountered in normal building design. While this standard refers to“Building Code Requ
5、irements for Structural Concrete (ACI 318)” for manyrequirements, it puts forth special requirements for the unique cases of staticand dynamic loading from funnel flow, mass flow, concentric flow, and asym-metric flow in silos, and the special loadings on stacking tubes. The standardincludes require
6、ments for seismic design and hopper bottom design.Keywords: asymmetric flow; bins; circumferential bending; concrete;concrete construction; dead loads; dynamic loads: earthquake resistantstructures; formwork (construction); funnel flow; granular materials; hop-pers; jumpforms; lateral loads: loads (
7、forces); lowering tubes; mass flow;overpressure; quality control; reinforced concrete; reinforcing steels; silos;slipform construction; stacking tubes; stave silos; stresses; structural analysis;structural design; thermal stresses; walls.CONTENTSChapter 1General, p. 313-21.1Introduction1.2Definition
8、s1.3Scope1.4Drawings, specifications, and calculationsChapter 2Materials, p. 313-32.1General2.2Cements2.3Aggregates2.4Water2.5Admixtures2.6Metal2.7Precast concrete staves2.8Tests of materialsChapter 3Construction requirements, p. 313-33.1General3.2Concrete quality3.3Sampling and testing concrete3.4D
9、etails and placement of reinforcement3.5Forms3.6Concrete placing and finishing3.7Concrete protection and curing3.8Lining and coating3.9Tolerances for slipformed and jumpformed structuresChapter 4Design, p. 313-44.1NotationStandard Practice for Design and Construction of Concrete Silos and Stacking T
10、ubes for Storing Granular Materials (ACI 313-97)An ACI StandardACI 313-97Mostafa H. MahmoudChairmanVahe A. Aprahamian Donald MidgleyWilliam D. Arockiasamy German R. Gurfinkel Jack MollLeon Bialkowski Ernest C. Harris Lee A. NashAlfred G. Bishara Donald S. Jack Rodney M. NohrWilliam H. Bokhoven Richa
11、rd T. Jenkyn J. Michael RotterWilliam L. Clark Michael E. Johnson John E. SadlerJames M. Ebmeier Robert D. Johnson Sargis S. SafarianStephen G. Frankosky F. Thomas Johnston Joseph R. TuckerReported by ACI Committee 313313-2 ACI STANDARD4.2General4.3Details and placement of reinforcement4.4Loads4.5Wa
12、ll design4.6Hopper design4.7Column design4.8Foundation designChapter 5Concrete stave industrial silos, p. 313-95.1Notation5.2Scope5.3Coatings5.4Erection tolerances5.5Wall design5.6Hoops for stave silos5.7Concrete stave testingChapter 6Post-tensioned concrete silos, p. 313-126.1Notation6.2Scope6.3Pos
13、t-tensioning systems6.4Tendon systems6.5Bonded tendons6.6Unbonded tendons6.7Post-tensioning ducts6.8Wrapped systems6.9Details and placement of non-prestressedreinforcement6.10Wall openings6.11Stressing records6.12Design6.13Vertical bending moment and shear due topost-tensioning6.14TolerancesChapter
14、7Stacking tubes, p. 313-157.1Scope7.2General layout7.3Loads7.4Load combinations7.5Tube wall design7.6Foundation or reclaim tunnelChapter 8Specified and recommended references, p. 313-17Appendix ANotation, p. 313-17CHAPTER 1GENERAL1.1IntroductionThis document, which covers design and construction ofc
15、oncrete silos and stacking tubes for storing granular mate-rials, replaced the 1968 ACI Committee 313 Report 65-37and was adopted as an ACI Standard in March 1977 as ACI313-77. It was subsequently revised in 1983 and 1991. Thecurrent revision reflects the most recent state-of-the-art instructural de
16、sign, detail, and construction of concrete silosand stacking tubes.Static pressures are exerted by the stored material at restand shall be computed by methods presented. Flow pressuresthat differ from static pressures are exerted by the storedmaterial during flow and also shall be computed by themet
17、hods presented.Design of the structures shall consider both static and flowloading.Applicable sections of ACI 318 shall apply.1.2DefinitionsThe term “silo,” as used herein, applies to any uprightcontainer for storing bulk granular material.Alternate names such as “bins” and “bunkers” are used indiff
18、erent localities, but for purposes of this Standard, all suchstructures are considered to be silos.“Stacking tubes” or “lowering tubes” are relatively slender,free-standing, tubular concrete structures used to stack conicalpiles of granular materials. See Commentary Section 7.2.“Slipformed” silos ar
19、e constructed using a typically 4 ft.(1.2 m) high continuously moving form.“Jumpformed” silos are constructed using three typically4 ft. (1.2 m) high fixed forms. The bottom lift is jumped tothe top position after the concrete hardens sufficiently.A “hopper” is the sloping, walled portion at the bot
20、tom ofa silo.“Stave silos” are silos assembled from small precastconcrete units called “staves,” usually tongued and grooved,and held together by exterior adjustable steel hoops.Other special terms are defined in the Commentary.1.3ScopeThis Standard covers the design and construction ofconcrete silo
21、s and stacking tubes for storing granular materials.Silos for storing of ensilage have different requirements andare not included. However, industrial stave silos for storageof granular materials are included.Coverage of precast concrete is limited to that for industrialstave silos.The Standard is b
22、ased on the strength design method.Provisions for the effect of hot stored material are included.Explanations of requirements of the Standard, additionaldesign information, and typical details are found in theCommentary.1.4Drawings, specifications, and calculations1.4.1 Project drawings and project
23、specifications for silosshall be prepared under the direct supervision of and bear theseal of the engineer.1.4.2 Project drawings and project specifications shallshow all features of the work, naming the stored materialsassumed in the design and stating their properties, andincluding the size and po
24、sition of all structural components,connections and reinforcing steel, the required concretestrength, and the required strength or grade of reinforcingand structural steel.DESIGN AND CONSTRUCTION OF CONCRETE SILOS AND STACKING TUBES 313-3CHAPTER 2MATERIALS2.1GeneralAll materials and tests of materia
25、ls shall conform to ACI301, except as otherwise specified.2.2CementsCement shall conform to ASTM C 150 (Types I, IA, II,IIAA, III and IIIA), ASTM C 595 (excluding Types S, SA,IS and IS-A), or ASTM C 845.2.3AggregatesThe nominal maximum size of aggregate for slipformedconcrete shall not be larger tha
26、n one-eighth of the narrowestdimension between sides of wall forms, nor larger thanthree-eighths of the minimum clear spacing between indi-vidual reinforcing bars or vertical bundles of bars.2.4WaterWater for concrete shall be potable, free from injuriousamounts of substances that may be harmful to
27、concrete orsteel. Non-potable water may be used only if it producesmortar cubes, prepared according to ASTM C 109, having 7-and 28-day strengths equal to at least the strength of similarspecimens made with potable water.2.5Admixtures2.5.1 Air-entraining, water reducing, retarding or acceler-ating ad
28、mixtures that may be required for specific construc-tion conditions shall be submitted to the engineer forapproval prior to their use.2.6Metal2.6.1 Hoop post-tensioning rods shall be hot-dip galva-nized or otherwise protected from corrosion. Connectors,nuts and lugs shall either be hot-dip galvanize
29、d or made fromcorrosion-resistant castings or corrosion-resistant steel.Galvanizing shall conform to ASTM A 123.2.6.2 Malleable iron castings shall conform to ASTM A 47.2.7Precast concrete staves2.7.1 Materials for staves manufactured by the dry-packvibratory method shall conform to ASTM C 55.2.7.2
30、Before a stave is used in a silo, drying shrinkage shallhave caused the stave to come within 90 percent of itsequilibrium weight and length as defined by ASTM C 426.2.8Tests of materials2.8.1 Tests of materials used in concrete construction shallbe made as required by the applicable building codes a
31、nd theengineer. All material tests shall be by an agency acceptableto the engineer.2.8.2 Tests of materials shall be made in accordance withthe applicable ASTM standards. The complete record ofsuch tests shall be available for inspection during theprogress of the work, and a complete set of these do
32、cumentsshall be preserved by the engineer or owner for at least 2 yearsafter completion of the construction.2.8.3 Silo stave testsThe results of mechanical tests ofsilo staves and stave assemblies shall be used as criteria forstructural design of stave silos. The application of the testresults is gi
33、ven in Chapter 5. Example methods ofperforming the necessary tests are given in the Commentary.CHAPTER 3CONSTRUCTION REQUIREMENTS3.1GeneralConcrete quality control, methods of determining concretestrength, field tests, concrete proportions and consistency,mixing and placing, formwork, details of rei
34、nforcement andstructural members shall conform to ACI 301, except asspecified otherwise herein.3.2Concrete quality3.2.1 The compressive strength specified for cast-in-placeconcrete shall be not less than 4000 psi (28 MPa) at 28 days.The compressive strength specified for concrete used inprecast unit
35、s shall be not less than 4000 psi (28 MPa) at28 days. The acceptance strength shall conform to ACI 301.3.2.2 Exterior concrete in silo or stacking tube walls thatwill be exposed to cycles of freezing and thawing shall be airentrained.3.3Sampling and testing concrete3.3.1 For strength tests, at least
36、 one set of three specimensshall be made and tested of the concrete placed during each8 hrs or fraction thereof.3.3.2 Accelerated curing and testing of concrete cylindersshall conform to ASTM C 684.3.4Details and placement of reinforcement3.4.1 Horizontal tensile reinforcement in silo and hopperwall
37、s shall not be bundled.3.4.2 Horizontal reinforcement shall be accurately placed andadequately supported. It shall be physically secured to verticalreinforcement or other adequate supports to prevent displace-ment during movement of forms or placement of concrete.3.4.3 Silo walls that are 9 in. (230
38、 mm) or more in thick-ness shall have two layers of horizontal and vertical steel.3.4.4 The minimum concrete cover provided for reinforce-ment shall conform to ACI 318 for cast-in-place concrete(non-prestressed), except as noted in Section 4.3.10.3.5Forms3.5.1 The design, fabrication, erection and o
39、peration of aslipform or jumpform system for a silo or stacking tube wallshall meet the appropriate requirements of ACI 347.3.5.2 Forms shall be tight and rigid to maintain thefinished concrete wall thickness within the specified dimen-sional tolerances given in Section 3.9.3.5.3 Slipform systems sh
40、all include an approved means ofdetermining and controlling level at each jack unit.3.6Concrete placing and finishing3.6.1 Construction joints in silos shall not be permittedunless shown on the project drawings or specificallyapproved by the engineer.3.6.2 Concrete shall be deposited within 5 ft. (1
41、.5 m) of itsfinal position in a way that will prevent segregation and shall313-4 ACI STANDARDnot be worked or vibrated a distance of more than 5 ft. (1.5 m)from the point of initial deposit.3.6.3 As soon as forms have been raised (or removed),vertical wall surfaces shall be finished by filling voids
42、 withmortar made from the same materials (cement, sand andwater) as used in the wall and by applying a “smooth rubbedfinish” in accordance with Section 10.3.1 of ACI 301.3.7Concrete protection and curing3.7.1 Cold weather concreting may begin when tempera-ture is 24 F (4 C) and rising, provided that
43、 the protectionmethod will allow 500 psi (4 MPa) compressive strengthgain before the concrete temperature drops below 32 F (0 C).For cold weather concreting, ACI 306R recommendationsshall be used where applicable.3.7.2 In hot weather, measures shall be taken to preventdrying of the concrete before a
44、pplication of a curingcompound. For hot weather concreting, ACI 305R recom-mendations shall be used where applicable.3.7.3 Where the wall surfaces will remain moist naturallyfor 5 days, no curing measures are required. Otherwise,curing measures conforming to ACI 308 shall be used.3.7.4 Where curing
45、measures are required, they shall beprovided before the exposed exterior surfaces begin to dry,but after the patching and finishing have been completed.Wall surfaces shall be protected against damage from rain,running water or freezing.3.7.5 Curing compounds shall not be used on the insidesurfaces o
46、f silos unless required by the project drawings orproject specifications, or unless specifically approved by theengineer. When curing of interior surfaces is required, non-toxic compounds and ventilation or other methods ofassuring worker safety shall be used.3.7.6 Curing compound shall be a non-sta
47、ining, resin basetype complying with ASTM C 309, Type 2, and shall beapplied in strict accordance with the manufacturers instruc-tions. Waxbase curing compounds shall not be permitted. Ifa curing compound is used on the interior surfaces of silos tobe used for storing materials for food, the compoun
48、d shall benon-toxic, non-flaking and otherwise non-deleterious.3.8Lining and coating3.8.1 Linings or coatings used to protect the structure fromwear and abrasion, or used to enhance flowability, shall becomposed of materials that are non-contaminating to thestored material.3.8.2 Lining materials ins
49、talled in sheet form shall befastened to the structure with top edges and side seams sealedto prevent entrance of stored material behind the lining.3.8.3 Coatings used as barriers against moisture or asbarriers against chemical attack shall conform to ACI 515.1R.3.9Tolerances for slipformed and jumpformed structures3.9.1 Translation of silo centerline or rotational (spiral) ofwall:For heights 100 ft. (30 m) or less 3 in. (75 mm)For heights greater than 100 ft. (30 m), 1/400times the height, but n
