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1、ACI 523.3R-93 Guide for Cellular Concretes Above 50 pcf, and for Aggregate Concretes Above 50 pcf with Compressive Strengths Less Than 2500 psi Reported by Committee 523 George C. Hoff Leo E. Rivkind Chairman Secretary Frank M. Coda Robert A. Crist Richard J. Frazier* Richard E. Galer Ernst Gruenwal
2、d W.C. Hansen Leo M. Legatski Albert Litvin Robert G. Mathey Fred C. McCormick Richard J. OHeir Thomas W. Reichard Owen Richards Robert E. Tobin Rudolph C. Valore, Jr. William F. Wescott * Deceased. Members of the Committee voting on the 1993 revisions: Fouad H. Fouad Chairman Theodore W. Bremner Ph
3、ilip M. Carkner Hubert T. Dudley Werner H. Gumpertz Michael Healy George C. Hoff Gordon D. Lerch Albert Litvin William R. MacDonald This guide presents information on materials, fabrication, properties, Chapter l-General, design, and handling of cellular concretes with oven-dry densities greater tha
4、n 50 pcf (800 kg/m3) and aggregate concretes with oven-dry densities 1.1-Scope above 50 pcf (800 kg/m3) but whose compressive strengths are less than 1.2-Objective 2500 psi (17.24 MPa). The usual density range of the concrete considered 1.3-Definitions Keywords: cellular concretes; compressive stren
5、gth; concrete construction; fire resistance; formwork (construction); insulating concretes; lightweight aggregate concretes; lightweight concretes; mix proportioning; modulus of elasticity; precast concrete; shear properties; splitting tensile strength; structural design; thermal conductivity. Leo A
6、. Legatski Secretary Henry N. Marsh, Jr. Jan R. Prusinski Leo E. Rivkind Rudolph C. Valore, Jr. pg. 5233R-2 is 50 pcf to 120 pcf. Those concretes in the lower portion of this range are 1.4-Standards and ACI documents cited in this report generally used for thermal and sound insulation fills for roof
7、s, walls, and floors. At the higher densities they are used in cast-in-place walls, floors, and roofs, and also for precast elements such as wall and floor panels. Chapter 2-Materials, pg. 523.3R-3 2.1-Aggregates 2.2-Portland cement 2.3-Mixing water 2.4-Foam concrete 2.5-Fibers CONTENTS Introduction
8、, pg. 523.3R-2 ACI Committee Reports, Guides, Standard Practices, and Commentaries are intended for guidance in designing, plan- ning, executing, or inspecting construction and in preparing specifications. References to these documents shall not be made in the Project Documents. If items found in th
9、ese documents are desired to be a part of the Project Docu- ments, they should be phrased in mandatory language and incorporated into the Project Documents. 2.6-Admixtures 2.7-Pozzolans Chapter 3-Mixing and handling, pg. 523.3R-5 3.1-Storage of materials ACI 523.3R-93 supersedes ACI 523.3R-75 (Revis
10、ed 1982) (Reapproved 1987) and became effective November 1, 1993. Copyright 8 1975, American Concrete Institute. All rights reserved including rights of reproduction and use in any form or by any means, including the making of copies by any photo process, or by any elec- tronic or mechanical device,
11、 printed or written or oral, or recording for sound or visual reproduction, or for use in any knowledge or retrieval system or device, unless permission in writing is obtained from the copyright proprietors. 523.3R-93 523.3R-2 ACI COMMlTTEE REPORT 3.2-Mixing procedures 3.3-Conveying Chapter 4-Formin
12、g and placing, pg. 523.3R-5 4.1-Form systems 4.2-Placing 4.3-Finishing Chapter 5-Properties, pg. 523.3R-6 5.1-General 5.2-Notation 5.3-Cellular concrete properties 5.4-Group I ASTM C 332 aggregate concrete pro- perties 5.5-Group II ASTM C 332 aggregate concrete pro- perties Chapter 6-Design consider
13、ations, pg. 523.3R-10 6.l-General 6.2-Structural design Chapter 7-Proportioning of mixes, pg. 523.3R-11 7.l-General 7.2-Material properties 7.3-Selection of quantities Chapter 8-Fire resistance, pg. 523.3R-13 References, pg. 523.3R-14 INTRODUCTION The concretes which are the subject of this guide ha
14、ve applications ranging from insulating fills to structural ele- ments. This is made possible mainly by the control of density which in turn affects other properties such as strength, modulus of elasticity, thermal conductivity, etc. Some of the present commercial uses of these concretes are: 1. Fil
15、ls for thermal and sound insulation of floors, walls, and roofs 2. Cast-in-place walls, floors, and roofs 3. Precast elements such as wall and floor panels. The steadily increasing use of these concretes and the fact that they are specifically not covered in other ACI guides and standards have led t
16、o the preparation of this guide. CHAPTER 1-GENERAL l.l-Scope This guide applies to all cellular concretes which weigh more than 50 pcf (800 kg/m3) oven-dry and also to aggregate concretes which weigh more than 50 pcf (800 kg/m3) oven-dry but have a compressive strength less than 2500 psi (175 kgf/cm
17、2). Lightweight aggregate con- cretes of higher strength are, by definition, within the scope of ACI Committee 213, Lightweight Aggregates and Lightweight Aggregate Concrete. Both precast and cast-in-place concretes are within the scope of this guide. 1.2-Objective The objective is to assemble, in t
18、his guide, the pre- sently available information relating to the properties and use of the subject concretes. It is intended that such in- formation will be an aid in the selection, proportioning, production, and use of these concretes. 1.3-Definitions The terms “cellular concrete” and “aggregate co
19、ncrete” are used throughout this guide. These terms have many meanings throughout the various areas of concrete tech- nology but are defined as follows for use in this guide: 1.3.1 Cellular concretes-The cellular concretes re- ferred to in this guide are lightweight concretes which contain stable ai
20、r or gas cells uniformly distributed in the mix. In the density range covered by this guide, cellular concretes commonly include natural or manufactured sand aggregate. Other types of aggregates may be added; for example, manufactured lightweight aggregates such as expanded clay, shale, slate, sinte
21、red fly ash, perlite, and vermiculite as well as natural lightweight aggregates such as pumice, scoria, or tuff. The air cells are usually added at the mixer as a stable preformed foam metered from a calibrated nozzle and thoroughly blended into the mix. The air cells may also be formed mechanically
22、 by en- trapping air during high speed mixing of the concrete materials containing a foaming agent. It is likewise pos- sible to form gas cells in the mix as the product of a chemical reaction. This guide does not cover products or processes which use gas evolving chemical reactions. The air cells i
23、n cellular concrete are predominantly macro- scopic bubbles as contrasted with the predominantly microscopic bubbles in air-entrained concrete. 1.3.2 Aggregate concretes-The aggregate concretes re- ferred to in this guide are made with lightweight aggre- gates such as expanded clay, shale, slate, sl
24、ag, sintered fly ash, perlite and vermiculite or natural aggregates such as pumice, scoria, or tuff. These aggregates are used with or without the addition of sand. By definition these con- cretes contain no air cells in the paste other than that entrapped by normal mixing and from conventional air-
25、 entraining agents. 1.4-Standards and ACI documents cited in this report The standards of the various standards-producing or- ganizations and ACI documents referred to in this docu- ment are listed below with their serial designation. 1.4.1 ACI documents 211.2 Standard Practice for Selecting Proport
26、ions for Structural Lightweight Concrete 212.3R Chemical Admixtures for Concrete -,-,- CELLULAR CONCRETES 523.3R-3 213R Guide for Structural Lightweight Aggregate Concrete 318 Building Code Requirements for Reinforced Concrete 347R Guide to Formwork for Concrete 408.1R Suggested Development Splice a
27、nd Standard Hook Provisions for Deformed Bars in Tension 426R Shear Strength of Reinforced Concrete Mem- bers 517.2R Accelerated Curing of Concrete at Atmospheric Pressure 544.1R State-of-the-Art Report on Fiber Reinforced Concrete 1.4.2 ASTM standards C 33 C 39 C 70 C 109 C 128 C 138 C 144 C 150 C
28、157 C 173 C 177 C 219 C 260 C 330 C 332 C469 C 494 C496 C567 C 595 C 618 Standard Specification for Concrete Aggregates Standard Test Method for Compressive Strength of Cylindrical Concrete Specimens Standard Test Method for Surface Moisture in Fine Aggregate Standard Test Method for Compressive Str
29、ength of Hydraulic Cement Mortars (using 2 in. or 50 mm cube specimens) Standard Test Method for Specific Gravity and Absorption of Fine Aggregates Standard Test Method for Unit Weight, Yield, and Air Content (Gravimetric) of Concrete Standard Specification for Aggregate for Mason- ry Mortar Standar
30、d Specification for Portland Cement Standard Test Method for Length Change of Hardened Cement Mortar and Concrete Standard Test Method for Air Content of Freshly Mixed Concrete by the Volumetric Method Standard Test Method for Steady-State Thermal Transmission Properties by Means of the Guarded Hot
31、Plate Terminology Relating to Hydraulic Cement Standard Specification for Air-Entraining Ad- mixtures for Concrete Standard Specification for Lightweight Aggre- gates for Structural Concrete Standard Specification for Lightweight Aggre- gates for Insulating Concrete Standard Test Method for Static M
32、odulus of Elasticity and Poissons Ratio of Concrete in Compression Standard Specification for Chemical Admixtures for Concrete Standard Test Method for Splitting Tensile Strength of Cylindrical Concrete Specimens Standard Test Method for Unit Weight of Struc- tural Lightweight Concrete Standard Spec
33、ification for Blended Hydraulic Cements Standard Specification for Fly Ash and Raw or Calcined Natural Pozzolans for Use as a Mineral Admixture in Portland Cement Concrete C 796 Standard Method of Testing Foaming Agents for Use in Producing Cellular Concrete Using Pre- formed Foam C 869 Standard Spe
34、cification for Foaming Agents Used in Making Preformed Foam for Cellular Con- crete E 72 Standard Method for conducting Strength of Panels for Building Construction 1.4.3 Structural Welding Code-Reinforcing Steel AWS D12.1 Recommended practice for Welding Rein- forcing Steel, Metal Inserts, and Conn
35、ec- tions in Reinforced Concrete Construction ACI publications are available from: American Concrete Institute P.O. Box 19150 Detroit, Michigan 48219 ASTM standards may be obtained from: American Society for Testing Materials 1916 Race St. Philadelphia, Pa. 19103 American Welding Society publication
36、s are available from: American Welding Society 550 N.W. LeJeune Road Miami, Fl. 33135 CHAPTER 2-MATERIALS 2.1-Aggregates 2.1.1 Concrete aggregates should conform to ASTM Specifications C 33, C 144, C 332, or C 330 with the provision that aggregates failing to meet these speci- fications but which ha
37、ve been shown by test or actual service to produce concrete of the required unit weight, strength, durability, fire resistance, and wearing qualities may be used under ACI 318 when permitted by the authority having jurisdiction. 2.1.2 There are two groups of lightweight aggregates that are described
38、 in ASTM C 332 which are applicable to the type of concrete covered in this guide. Group I aggregates are prepared by heat processing to produce products such as expanded perlite and exfoliated vermi- culite. Group II aggregates are prepared by expanding, calcining, or sintering products such as bla
39、st furnace slag, clay, diatomite, fly ash, shale, or slate; and aggregates prepared by processing natural materials, such as pumice, scoria, or tuff. 2.1.3 The maximum size of aggregate should in no case exceed one-fifth of the narrowest dimension be- tween sides of forms, three-fourths of the minim
40、um clear spacing between individual reinforcing bars or bundles of -,-,- 523.3R-4 ACI COMMITTEE REPORT bars, nor one-third of the depth of slabs. These limi- tations may be waived if workability and methods of con- solidation are such that the concrete can be placed with- out honeycomb or excessive
41、voids. 2.2-Portland cement Portland cement, portland blast furnace slag cement, or portland pozzolan cement may be used. They should conform to ASTM specifications C 150 or C 595. High- early-strength cements, Type III and IIIA, are often used to advantage in these concretes. 2.3-Mixing water Mixing
42、 water for concrete should be fresh, clean, and drinkable, except that undrinkable water may be used if it produces mortar cubes having 7- and 28-day strengths equal to at least 90 percent of the strength of similar specimens made with water from a municipal supply. The strength comparison should be
43、 made on mortars, identi- cal except for the mixing water, prepared and tested in accordance with ASTM C 109. 2.4-Foam concrete Foam cells in cellular concrete may be formed either by: (1) preforming an aqueous foam or (2) forming foam in the mixer (mix-foaming). The foam concentrate must be of such
44、 chemical composition that it is capable of producing stable foam cells in concrete which can resist the physical and chemical forces imposed during mixing, pumping, placing, and setting of the concrete. Change in concrete density during the time until initial set is a measure of the stability of th
45、e foam. 2.4.1 Preformed foam -Preformed foam is made by blending the foam concentrate, water, and compressed air in predetermined proportions in a foam generator calibrated for discharge rate. The foam is added, in measured amounts, to the slurry of cement, aggregate, and water in either batch or co
46、ntinuous mixing equip- ment to produce concrete of the desired density. 2.4.2 Mix-foaming-Mix-foaming results from high speed, high shear mixing, in an open mixer, of a slurry of water, cement, foam concentrate, and aggregate. The mix density is a function of the quantity and characteristics of the
47、foam concentrate, the aggregates, if any, the time and speed of mixing, and the mixer characteristics. 2.5-Fibers Nonload cracking of cellular concretes at early ages (due to thermal and moisture loss volume changes) can be reduced by the addition of suitable fibers to the mix. Fibers for this purpo
48、se must bond to the concrete, have a high modulus of elasticity and be of sufficient length, size, and number to develop the required tensile force at any section. Steel, resin-coated glass or alkali-resistant glass fibers are among the fibers that could satisfy the above requirements.1 Glass fibers
49、 are often used in cellular concrete. Con- siderable research has been done on the use of glass fibers in portland cement products. A state-of-the-art report on the use of all types of fibers in both normal weight and lightweight concretes has been prepared by ACI Committee 544.2 This report includes information on fiber types and sizes, and methods of handling, mix- ing, and placing concrete containing fibers which is directly applicable to the concretes of this guide. 2.6-Admixtures Admixtures may be used w
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