211.9r-18: guide to selecting proportions for pumpable concrete · 2020. 5. 12. · aci 211.9r-18...

Guide to Selecting Proportions for Pumpable ConcreteReported by ACI Committee 211

AC

I 211

.9R

-18

Copyright American Concrete Institute Provided by IHS Markit under license with ACI Licensee=http://www.GigaPaper.ir

Not for Resale, 04/01/2019 08:53:40 MDTNo reproduction or networking permitted without license from IHS

--`,,`,`,,,,,````,``,,,,,,`,,,,-`-`,,`,,`,`,,`---

First PrintingAugust 2018

ISBN: 978-1-64195-028-2

Guide to Selecting Proportions for Pumpable Concrete

Copyright by the American Concrete Institute, Farmington Hills, MI. All rights reserved. This material may not be reproduced or copied, in whole or part, in any printed, mechanical, electronic, film, or other distribution and storage media, without the written consent of ACI.

The technical committees responsible for ACI committee reports and standards strive to avoid ambiguities, omissions, and errors in these documents. In spite of these efforts, the users of ACI documents occasionally find information or requirements that may be subject to more than one interpretation or may be incomplete or incorrect. Users who have suggestions for the improvement of ACI documents are requested to contact ACI via the errata website at http://concrete.org/Publications/DocumentErrata.aspx. Proper use of this document includes periodically checking for errata for the most up-to-date revisions.

ACI committee documents are intended for the use of individuals who are competent to evaluate the significance and limitations of its content and recommendations and who will accept responsibility for the application of the material it contains. Individuals who use this publication in any way assume all risk and accept total responsibility for the application and use of this information.

All information in this publication is provided “as is” without warranty of any kind, either express or implied, including but not limited to, the implied warranties of merchantability, fitness for a particular purpose or non-infringement.

ACI and its members disclaim liability for damages of any kind, including any special, indirect, incidental, or consequential damages, including without limitation, lost revenues or lost profits, which may result from the use of this publication.

It is the responsibility of the user of this document to establish health and safety practices appropriate to the specific circumstances involved with its use. ACI does not make any representations with regard to health and safety issues and the use of this document. The user must determine the applicability of all regulatory limitations before applying the document and must comply with all applicable laws and regulations, including but not limited to, United States Occupational Safety and Health Administration (OSHA) health and safety standards.

Participation by governmental representatives in the work of the American Concrete Institute and in the development of Institute standards does not constitute governmental endorsement of ACI or the standards that it develops.

Order information: ACI documents are available in print, by download, through electronic subscription, or reprint and may be obtained by contacting ACI.

Most ACI standards and committee reports are gathered together in the annually revised the ACI Collection of Concrete Codes, Specifications, and Practices.

American Concrete Institute38800 Country Club DriveFarmington Hills, MI 48331Phone: +1.248.848.3700Fax: +1.248.848.3701

www.concrete.org



--`,,`,`,,,,,````,``,,,,,,`,,,,-`-`,,`,,`,`,,`---

http://concrete.org

ACI Committee Reports, Guides, and Commentaries are intended for guidance in planning, designing, executing, and inspecting construction. This document is intended for the use of individuals who are competent to evaluate the significance and limitations of its content and recommendations and who will accept responsibility for the application of the material it contains. The American Concrete Institute disclaims any and all responsibility for the stated principles. The Institute shall not be liable for any loss or damage arising therefrom.

Reference to this document shall not be made in contract documents. If items found in this document are desired by the Architect/Engineer to be a part of the contract documents, they shall be restated in mandatory language for incorporation by the Architect/Engineer.

ACI 211.9R-18 was adopted and published August 2018.Copyright © 2018, 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 electronic or mechanical device, printed, 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.

1

ACI 211.9R-18

Guide to Selecting Proportions for Pumpable Concrete

Reported by ACI Committee 211

Gary F. Knight, Chair Timothy S. Folks, Vice Chair Ed T. McGuire, Secretary

William L. BarringerKatie J. Bartojay

Muhammed P. A. BasheerJames C. BlankenshipCasimir J. Bognacki

Ramon L. CarrasquilloBryan R. Castles

Teck L. ChuaJohn F. Cook

David A. CrockerD. Gene Daniel

Kirk K. DeadrickDonald E. Dixon

Bernard J. Eckholdt IIIDarrell F. Elliot

David W. FowlerG. Terry HarrisRichard D. Hill

David L. HollingsworthSaid Iravani

Tarif M. JaberRobert S. Jenkins

Joe KelleyEric P. Koehler

Frank A. KozeliskiTyler Ley

Darmawan LudirdjaAllyn C. Luke

Kevin A. MacDonaldWarren E. McPherson Jr.

Karthik H. OblaH. Celik Ozyildirum

James S. Pierce

Steven A. RaganRoyce J. Rhoads

John P. RiesG. Michael RobinsonJames M. Shilstone Jr.

Ava ShypulaWoodward L. Vogt

Michael A. Whisonant

Subcommittee MembersYasar Yahia Abualrous

David AnstineDale P. BentzZane Bussler

Laurence M. ClodicKenneth W. Day

Dimitri FeysPatrick J. Harrison

Plinio Estuardo HerreraGene HightowerBerndt Kanduth

Kenneth G. Kazanis

Guy LortieBlaine B. NyeBryan L. Petty

Nicholas J. PopoffDomenick Thomas Ruttura

Lawrence L. Sutter

Paul D. TennisPaul J. Thomas

James R. Van AckerHermann W. Wentz

Consulting MemberJames N. Lingscheit

The committee would like to thank J. Bury for his contribution to this guide.

This guide addresses methods for selecting proportions for hydraulic-cement concrete placed by pumping. Specific numerical guidelines are given as applicable to mixture component propor-tions that lead to the most efficient concrete pumping results. Comments are also included in this guide on how pumping affects the supplied concrete and how the proportions affect the concrete’s pumpability. This guide complements ACI 304.2R and is also intended as a supplement to ACI 211.1 and ACI 211.2.

The mass of an object is defined as the amount of matter that is present. Mass is independent of any other property; weight is the force arising from specific gravitational field or other acceleration acting on a mass. The weight is thus dependent on both the mass and the acceleration due to gravity rotation. In the common engineering system, a pound of mass is accelerated by gravity to be 1 lb of force. There is no need for distinction, and mass and weight are often used interchangeably in that the numerical values are the same. A mass of 1 lb exerts a weight of 1 lb. There is a hidden gravitational constant. In the SI system, mass is expressed in grams and weight in Newtons. A mass of 1 kg exerts a weight of 9.81 N. It is correct, therefore, to use the term “mass” when determining how much material is being loaded into the plant, and when the mixtures are designed and proportioned. The industry, however, conventionally uses weight for these items. In the common measurement system, this creates no confusion. Thus, the vernacular term for the massing



--`,,`,`,,,,,````,``,,,,,,`,,,,-`-`,,`,,`,`,,`---

American Concrete Institute – Copyrighted © Material – www.concrete.org

2 GUIDE TO SELECTING PROPORTIONS FOR PUMPABLE CONCRETE (ACI 211.9R-18)

elements of the concrete plant is the weigh hopper. The batch record showing masses of materials in the concrete mixture are collectively referred to as batch weights. In an acknowledgement of this widespread industry practice, and to make the document as widely useable as possible, the term “weight” is used throughout to represent mass in the text. This is technically incorrect but is in line with common practice. In all conversions, both mass and weight are given (kilograms and Newtons).

Keywords: admixtures; aggregate; cementitious material; concrete mixture design; fiber; grading; fineness modulus; lightweight aggregate; mass concrete; normalweight aggregate; pumpability; unit weight.

CONTENTS

CHAPTER 1—INTRODUCTION AND SCOPE, p. 21.1—Introduction, p. 21.2—Scope, p. 2

CHAPTER 2—DEFINITIONS, p. 2

CHAPTER 3—AGGREGATE GRADING, p. 23.1—Considerations, p. 23.2—Normalweight aggregate, p. 23.3—Lightweight aggregate, p. 4

CHAPTER 4—CEMENTITIOUS MATERIALS, p. 74.1—General, p. 7

CHAPTER 5—WATER, p. 75.1—General, p. 7

CHAPTER 6—ADMIXTURES, p. 76.1—General, p. 76.2—Admixture types, p. 7

CHAPTER 7—FIBER REINFORCEMENT, p. 8

CHAPTER 8—TRIAL MIXTURES AND PUMPABILITY TESTING, p. 8

CHAPTER 9—REFERENCES, p. 8Authored documents, p. 8

CHAPTER 1—INTRODUCTION AND SCOPE

1.1—IntroductionAs construction projects grow more sophisticated,

concrete placement by pumps has become one of the most widely used practices in construction. To meet the demand of the industry, concrete mixture proportions need to be designed considering pumpability requirements. However, when proportioning a mixture, pumpability is only one of several factors. Because hardened properties determine the durability and serviceability of concrete, the professional responsible for design of concrete mixtures should also consider exposure conditions, strength, curing characteristics, flowability, sustainability, delivery, and placement. In some cases, where these are in direct conflict, a compromise or

alternative solution is required. Given the prevalence and benefits of placement by pumping, it is sometimes critical to certain applications that the components and their mixture proportions be designed with consideration to pumpability. The extent to which attention should be given to the components and proportions in a mixture depends on the application and equipment being used.

1.2—ScopeThis guide addresses methods for selecting proportions

specific to hydraulic-cement concrete to be placed by pumping. The primary focus of this document is to discuss the principles of mixture proportioning for normalweight and lightweight concrete. Any specific information regarding pumping equipment and field practices are covered elsewhere (ACI 304.2R). The methods provided for selecting proportions for hydraulic cement begin with an approximation of the proportions intended to be checked by trial batches in the laboratory or field, which will then be adjusted as necessary to produce the desired pumpability characteristics while confirming it meets the other performance requirements such as durability and strength. Selection of the mixture proportions should be done by considering both fresh and hardened properties required for a given application. The size of the pump and pump line should be evaluated to accommodate the volume of coarse aggregates and nominal maximum aggregate size used in the mixture. This guide does not address slump because concrete of all slumps and slump flows can be successfully pumped, provided the proper equipment and mixture proportions are used. Slump or slump flow should meet other project and application requirements, as discussed in ACI 211.1.

CHAPTER 2—DEFINITIONSPlease refer to the latest version of “ACI Concrete

Terminology” for a comprehensive list of definitions.

CHAPTER 3—AGGREGATE GRADING

3.1—ConsiderationsQuality concrete proportioning begins with the appropriate

combined aggregate grading. This is also true for pumpable concrete. Consistency in grading promotes consistency in the pumpability of any mixture. Thus, aggregate grading should be monitored and blends adjusted when required to assure consistency in the combined aggregate grading.

3.2—Normalweight aggregate3.2.1 Coarse normalweight aggregate—The nominal

maximum size (NMS) of coarse aggregate is limited to one-third of the smallest inside diameter of the pipeline. The NMS required should be specified and provisions made for the elimination of oversized particles in the concrete by use of finish screening (ACI 304R; ASTM C33/C33M) or by careful selection of coarse aggregate.

The NMS has a significant effect on the volume of coarse aggregate that may be efficiently used. The quantity of coarse aggregate should be reduced as the NMS is reduced



--`,,`,`,,,,,````,``,,,,,,`,,,,-`-`,,`,,`,`,,`---


GUIDE TO SELECTING PROPORTIONS FOR PUMPABLE CONCRETE (ACI 211.9R-18) 3

because the greater total surface area of the smaller-diameter aggregate for a given weight of coarse aggregate requires more mortar to coat all surfaces. Reducing coarse aggregate content makes more mortar available to lubricate the pipeline wall and promotes mixture mobility. However, increasing mortar will increase the demand for paste because concrete with a smaller NMS requires more sand, which has an even higher surface area due to its smaller particle size compared to larger coarse aggregate.

3.2.2 Fine normalweight aggregate—The properties of fine aggregate or sand take on a more prominent role than coarse aggregate in the proportioning of pumpable mixtures. Together, with cementitious materials and water, the fine aggregate in a pumpable mixture provides the mortar that both conveys the coarse aggregates in suspension and allows adjustment to changes in the delivery line configuration.

The grading of fine aggregate for pumpability may not need to conform to the requirements of ASTM C33/C33M. Experience has shown that for optimum pumpability, 15 to 30 percent of fine aggregate should pass the No. 50 (300 µm) screen and 5 to 10 percent should pass the No. 100 (150

µm) screen. Fine aggregates that are deficient in either of these two sizes should be blended with selected fine sands, mineral fillers, or other materials to produce these desired percentages. Increasing the amount of No. 50 (300 µm) and No. 100 (150 µm) fractions could require additional water or admixture. To increase the cohesion of a concrete mixture, use of rheology or viscosity-modifying admixtures can be considered if the passing percentages are lower than desired.

The fineness modulus (FM) of fine aggregate meeting ASTM C33/C33M grading specifications will fall between 2.30 and 3.10. Pumpability of mixtures is generally improved with a decrease in the FM (finer fine aggregate). The FM alone, without stipulations for particle distribution, might not produce satisfactory results. Larger quantities of coarse aggregate may be used with a lower FM, as shown in Table 3.2.2. This resource is recommended as a guide to the amount of coarse aggregate to combine with fine aggregate of different FM values.

Fine aggregate for concrete can be obtained from natural deposits or manufactured by crushing coarser materials to the desired sizes. The pumping characteristics of concrete produced with different sources of fine aggregate can vary. The FM is a good indicator for determining the acceptability of natural or crushed fine aggregate for the mixture. Small quantities of mineral fillers (for example, crusher dust and limestone filler), supplementary cementitious materials, or both, are often useful in correcting deficiencies in the finer sizes. Successful pumping experience indicates that combining materials from separate sources often brings satisfactory results. Blending as little as 5 percent natural sand could render concrete mixtures with certain manufactured sands pumpable. Similarly, small additions (typically 5 to 10 percent) of manufactured fines may improve the pumpability of concrete mixtures containing natural sands.

As a guide for selecting suitable fine aggregate, the solid-line curves in Fig. 3.2.2a and 3.2.2b are suggested. In Fig. 3.2.2a, the percentage passing each screen size is shown together with ASTM limits whereas in Fig. 3.2.2b, the individual percent retained on each screen is shown. Both solid curves represent identical data. Although in practice it may be impossible to

Table 3.2.2—Volume of coarse aggregate per unit of volume of concrete

Nominal maximum size of aggregate, in.

(mm)

Volume of oven-dry-rodded coarse aggregate* per unit volume of concrete for different

fineness moduli of fine aggregate

2.40 2.60 2.80 3.00

3/8 (9.5) 0.50 0.48 0.46 0.44

1/2 (12.5) 0.59 0.57 0.55 0.53

3/4 (19.0) 0.66 0.64 0.62 0.60

1 (25.0) 0.71 0.69 0.67 0.65

1-1/2 (37.5) 0.75 0.73 0.71 0.69

*Volumes based on aggregates in oven-dry-rodded conditions as described in ASTM C29/C29M.Notes: These volumes are selected from empirical relationships to produce concrete with a degree of workability suitable for usual reinforced concrete construction. Table taken from ACI 211.1-91 Table 6.3.6 Refer to ASTM C136/C136M for calculation of FM.

Fig. 3.2.2a—Recommended normalweight fine aggregate grading (cumulative percent passing).



--`,,`,`,,,,,````,``,,,,,,`,,,,-`-`,,`,,`,`,,`---



duplicate this recommended fine aggregate grading exactly, fine aggregates having a grading closer to the upper limit (fine) are more desirable for pumping than those near the lower limit (coarse). The FM of this composite material is 2.68, the grading meets ASTM C33/C33M specifications and produces a smooth curve, and the percentages passing the No. 50 (300 µm) and No. 100 (150 µm) screens are well within the limits mentioned previously.

3.2.3 Combined normalweight aggregates—The combined coarse and fine aggregate occupies approximately 60 to 80 percent of the mixture volume. For combined grading purposes, fine and coarse aggregate should be considered as one, although fine and coarse aggregate are usually proportioned separately. Figure 3.2.3a is a recommended combined grading for evaluating the pumpability of a concrete mixture proportioned by combining the fine and coarse aggregate with NMS from 3/4 in. to 1-1/2 in. (19.5 to 37.5 mm).

The combined aggregate grading should be above the boundary limit to be ideal for pumping. Adjustments to combined aggregate grading to improve pumpability may include modification of the coarse-to-fine aggregate ratio or inclusion of another aggregate with an intermediate grading

between the coarse and fine aggregates. Figures 3.2.3b and 3.2.3c are examples that illustrate how Fig. 3.2.3a is used, with a NMS of 1 in. (25.0 mm). In Fig. 3.2.3b, the combined aggregate grading partially falls to the left of the boundary limit, suggesting that the mixture is not ideal for pumping. Figure 3.2.3c shows results of adjustments made that move the combined aggregate grading to the right of the boundary limit, indicating that the mixture is now ideal for pumping. The adjustments made could have included a modification of the coarse-to-fine aggregate ratio or the inclusion of another aggregate with the grading between that of the NMS and sand.

Tables 3.2.3a and 3.2.3b suggest volume ranges for determining the weights of coarse aggregate for pumpable mixtures depending on the FM of the fine aggregate. This information is based on the values shown in Table 3.2.2 and reflects differences in characteristics of rounded river gravel (Table 3.2.3a) and crushed stone (Table 3.2.3b).

3.3—Lightweight aggregateWhen pumping lightweight aggregate concrete is

required, some adjustments may be necessary to achieve the

Fig. 3.2.2b—Recommended normalweight fine aggregate grading (individual percent retained).

Fig. 3.2.3a—Recommended combined grading for evaluating the pumpability of concrete.

Fig. 3.2.3b—Example of a combined grading that may yield undesirable pumping characteristics (refer to Fig. 3.2.3a).

Fig. 3.2.3c—Example of a combined grading that may yield desirable pumping characteristics (refer to Fig. 3.2.3a).



--`,,`,`,,,,,````,``,,,,,,`,,,,-`-`,,`,,`,`,,`---



desired characteristics. The licensed design professional and contractor should be familiar with any mixture adjustments required before selecting a placement method. Consider consulting with the ready mixed concrete producer, admixture supplier, concrete pump supplier, and aggregate supplier to determine the optimal pump mixture.

3.3.1 Lightweight coarse aggregate—The grading of lightweight coarse aggregate should conform within the limits stated in ASTM C330/C330M, including permitted fluctuations in their unit weight. For batching lightweight coarse aggregate by volume rather than by weight, ACI 304.2R should be referenced to maintain consistency and volumetric yield.

Structural lightweight aggregates can have a coated or uncoated exterior surface, depending on the production method. They also can be rounded, cubical, or angular in shape. Proper allowances can be made for shape and surface texture to handle any type of lightweight aggregate in a pump mixture by slight changes in the ratio of mortar to coarse aggregate.

In some localities, lightweight coarse aggregates larger than the 3/16 in. (No. 4 [4.75 mm]) screen are produced in two separate fractions. These two sizes should be combined, preferably at the batch plant, to produce a blended total coarse aggregate combination that satisfies ASTM C330/C330M grading specifications. Uniformity of grading should be maintained from one batch to the next, as fluctuations will affect the degree of pumpability.

3.3.2 Lightweight fine aggregate—The grading of lightweight fine aggregate should also conform within the limits shown in ASTM C330/C330M. In addition, it is imperative to pay specific attention to the very fine fractions. Twenty to 35 percent of fines should pass the No. 50 (300 µm) screen and 10 to 20 percent should pass the No. 100 (150 µm) screen. If the lightweight fine aggregate is

deficient in these sizes, materials such as mineral fillers (for example, crusher dust or limestone filler), or supplementary cementitious materials in approximately the amount of the deficiency, will improve pumpability.

In some circumstances, it is possible to blend lightweight fine aggregate with natural sands. This practice, however, could involve dual considerations. Although replacing lightweight fines with natural sands can improve the overall grading of these combined fine aggregates, it could also adversely increase the weight of the finished concrete. These effects, however, can sometimes be minimized by using relatively small amounts of very fine natural sands if this combination results in improved grading. Although pumpability of a mixture can be enhanced by the addition of –50 to –200 mesh fractions in the fine aggregate, large increases in very fine sizes will require greater amounts of mixing water, which may result in strength reduction and increased drying shrinkage. Refer to ACI 211.2 for further information on the FM of lightweight fine aggregate. ACI 211.2 discusses issues that can arise when FM is based on weight or on volume.

3.3.3 Combined lightweight aggregates—Tables 3.3.3a and 3.3.3b are recommended as guides for the selection of the quantity of the coarse lightweight aggregate selected for trial mixtures in lightweight concrete when prewetted or saturated aggregates are used. Differences in particle shape, grading, surface characteristics, void content, and degree of presoaking could each have an influence on the optimum volume of coarse aggregate for a specific mortar. The tabulated values are only suggestions based on experience; optimum values may vary ±10 percent due to the local conditions, applications, or equipment used (refer to 3.3.4 for further details).

3.3.4 General considerations—The use of lightweight aggregate can significantly affect the performance of hardened concrete based on the amount of saturation. The porous nature

Table 3.2.3a—Suggested volumes, ft3/yd3 (m3/m3), of rounded river gravel for concrete to be pumped*

Type of sand

Coarse normalweight aggregate size

3/8 in. to No. 4 (9.5 to 4.75 mm)

1/2 in. to No. 4 (12.5 to 4.75 mm)

3/4 in. to No. 4 (19.0 to 4.75 mm)

1 in. to No. 4 (25.0 to 4.75 mm)

1-1/2 in. to No. 4 (37.5 to 4.75 mm)

CoarseFM = 2.80 to 3.00

10.50 to 11.60 (0.39 to 0.43)

13.00 to 14.10 (0.48 to 0.52)

15.70 to 16.80(0.58 to 062)

17.10 to 18.10 (0.63 to 0.67)

18.30 to 19.40 (0.68 to 0.72)

MediumFM = 2.60 to 2.80

11.00 to 12.10 (0.41 to 0.45)

13.50 to 14.60 (0.50 to 0.54)

16.30 to 17.30 (0.60 to 0.64)

17.60 to 18.60 (0.65 to 0.69)

18.90 to 19.90 (0.70 to 0.74)

FineFM = 2.40 to 2.60

11.60 to 12.60 (0.43 to 0.47)

14.10 to 15.10 (0.52 to 0.56)

16.80 to 17.80 (0.62 to 0.66)

18.10 to 19.20(0.67 to 0.71)

19.40 to 20.40 (0.72 to 0.76)

*This table is adopted from ACI 304.2R and derived from ACI Committee 304 experience for rounded river gravel having a dry unit weight of 96 lb/ft3 (1540 kg/m3).

Table 3.2.3b—Suggested volumes, ft3/yd3 (m3/m3), of crushed stone for concrete to be pumped*

Type of sand

Coarse normalweight aggregate size

3/8 in. to No. 4 (9.5 to 4.75 mm)

1/2 in. to No. 4 (12.5 to 4.75 mm)

3/4 in. to No. 4 (19.0 to 4.75 mm)

1 in. to No. 4 (25.0 to 4.75 mm)

1-1/2 in. to No. 4 (37.5 to 4.75 mm)


10.60 to 11.50(0.39 to 0.43)

12.90 to 13.90 (0.48 to 0.51)

15.60 to 16.60 (0.58 to 0.61)

17.10 to 18.00 (0.63 to 0.67)

18.50 to 19.40 (0.69 to 0.72)


11.10 to 12.00 (0.41 to 0.44)

13.40 to 14.40 (0.50 to 0.53)

16.10 to 17.10 (0.60 to 0.63)

17.50 to 18.50 (0.65 to 0.69)

18.90 to 19.90 (0.70 to 0.74)

FineFM = 2.40 to 2.60

11.50 to 12.50(0.43 to 0.46)

13.90 to 14.80 (0.51 to 0.55)

16.60 to 17.50 (0.61 to 0.65)

18.00 to 18.90 (0.67 to 0.70)

19.40 to 20.40 (0.72 to 0.76)

*This table was adopted from ACI 304.2R and derived from ACI Committee 304 experience for crushed stone aggregate having a dry loose unit weight of 85 lb/ft3 (1360 kg/m3).



--`,,`,`,,,,,````,``,,,,,,`,,,,-`-`,,`,,`,`,,`---



of lightweight aggregate may cause the material to absorb water when subjected to pumping pressures. Therefore, to achieve consistent pumpability for lightweight concrete, conditioning or prewetting the aggregate is required. The prewetting process aids in preventing the aggregate from absorbing water during the pumping process and allows the concrete to be delivered in a ready-to-pump condition. This minimizes slump loss, increases pumpability, and maintains consistency. Prewetting may not be as critical for lightweight aggregate with low absorption value, provided certain adjustments are made. The adjustments consist of: a) obtaining the acceptance samples at the point of placement; and b) recognizing that pump pressure will increase the absorption value of the lightweight aggregate. ACI 304.2R can be referenced for a more detailed discussion of free and absorbed water when pumping lightweight concrete. The pump-pressure-induced absorption value may be available from the lightweight aggregate supplier.

The length of time required to adequately prewet a lightweight aggregate is dependent on the absorption characteristics of the aggregate. Consult with the lightweight aggregate supplier, who may be able to provide more information.

Conditioning lightweight aggregate is attainable through any of the following (refer to 4.6 in ACI 213R-14):

a) Atmospheric—Using a soaker hose or sprinkler system to apply water to aggregate piles at the aggregate plant, batch plant, or both.

b) Thermal—Under controlled conditions at the lightweight aggregate plant, partially cooled aggregate is immersed in water after it leaves the rotary kiln.

c) Vacuum—Introducing a dry aggregate into a vessel from which air can be evacuated. The vessel is then filled with water and returned to atmospheric pressure. This should be performed at the aggregate plant.

Prewetting minimizes the mixing water being absorbed by the aggregate, therefore minimizing the slump loss during pumping. This additional moisture also increases the density of the lightweight aggregate, which in turn increases the density of the fresh concrete. This prewetting that will eventually be lost to the atmosphere in drying provides for extended internal curing.

3.3.4.1 Increasing water content—Absorption under atmospheric pressure can vary for different lightweight aggregate from 5 to 25 percent by weight. However, under the pressures exerted by pumping, absorption could increase substantially, which could reduce pumpability of the concrete. Therefore, to pump lightweight concrete, it may be necessary to account for such an increase in absorption by increasing the batch water content. Considering that absorbed water does not affect the water-to-cementitious material ratio (w/cm), when additional absorption due to pump pressure is ascertained, additional batch water can be added to the mixer truck at the project site, at the concrete batch plant, or at both locations.

3.3.4.2 High-percentage saturation—Vacuum saturation and thermal saturation are processes described in ACI 213R. Using

Table 3.3.3a—Suggested volumes, ft3/yd3 (m3/m3), of prewetted lightweight aggregate per yd3 of concrete to be pumped*

Type of fine aggregate

Coarse lightweight aggregate size, range

3/8 in. to No. 4(9.5 to 4.75 mm)

1/2 in. to No. 4(12.5 to 4.75 mm)

3/4 in. to No. 4(19.0 to 4.75 mm)


7.9 to 8.7 (0.29 to 0.32)

9.3 to 10.5 (0.34 to 0.39)

11.8 to 12.6 (0.44 to 0.47)


8.3 to 9.1 (0.31 to 0.34)

10.2 to 11.0 (0.38 to 0.41)

12.2 to 13.0 (0.45 to 0.48)

FineFM = 2.40 to 2.60

8.7 to 9.5 (0.32 to 0.35)

10.6 to 11.4 (0.39 to 0.42)

12.5 to 13.4 (0.46 to 0.50)

*Values shown in this table are in uncompacted ft3 of prewetted lightweight aggregate per yd3 (m3 per m3) of concrete. They may be applied to both crushed and coated particles. Total weight is acquired by multiplying these figures times the unit weight in lb/ft3 (kg/m3) for the particular aggregate being used. These data are derived from ACI Committee 304 experience and adopted from ACI 304.2R. Suggestions apply only to relatively low pump pressures in 4 in. (100 mm) pipelines. The sum of the vertical lift, in units of feet (meter), plus one-third the total length of the distribution line should preferably be less than 150 ft (3.81 m).

Table 3.3.3b—Suggested volumes, ft3/yd3 (m3/m3), of saturated lightweight aggregate per yd3 of concrete to be pumped*

Type of fine aggregate

Coarse lightweight aggregate size, range

3/8 in. to No. 4 (9.5 to 4.75 mm)

1/2 in. to No. 4 (12.5 to 4.75 mm)

3/4 in. to No. 4 (19.0 to 4.75 mm)


10.6 to 11.5 (0.39 to 0.43)

13.0 to 14.0 (0.48 to 0.52)

15.7 to 16.7 (0.58 to 0.62)


11.1 to 12.1 (0.41 to 0.45)

13.5 to 14.5 (0.50 to 0.54)

16.2 to 17.2 (0.60 to 0.64)

FineFM = 2.40 to 2.60

11.6 to 12.6 (0.43 to 0.47)

14.0 to 15.0 (0.52 to 0.56)

16. 7 to 17.7 (0.62 to 0.66)

*Values shown in this table are in uncompacted ft3 of saturated lightweight aggregate per yd3 (m3 per m3) of concrete. They may be applied to both crushed and coated particles. Total weight is acquired by multiplying these figures times the unit weight in lb per ft3 (kg/m3) for the particular lightweight aggregate being used These data are derived from ACI Committee 304 experience and adopted from ACI 304.2R.



--`,,`,`,,,,,````,``,,,,,,`,,,,-`-`,,`,,`,`,,`---



these processes will also limit the slump loss in pumping. The suggested volumes of coarse lightweight aggregates used with this degree of saturation are shown in Table 3.3.3b.

CHAPTER 4—CEMENTITIOUS MATERIALS

4.1—GeneralThe information provided in this guideline applies to

portland cement (ASTM C150/C150M; ASTM C595/C595M; ASTM C1157/C1157M). The determination of the cementitious materials content for a pumpable mixture follows many of the same basic principles used for any concrete. The use of extra quantities of cementitious materials as the only solution to the correction of pumping difficulties is shortsighted and uneconomical. It is far more desirable to first correct any deficiencies in the aggregate grading, especially in the fine aggregate fraction. With well-graded coarse and fine aggregates properly combined, the cement factors for pump mixtures will closely parallel those used in other concrete, as explained in ACI 211.1 and ACI 211.2.

Much has been written about the use of alternative materials as a substitution for cement, the scope of which is beyond this guide. For further discussions on the use of these materials in concrete, refer to ASTM C618, ASTM C989/C989M, and ASTM C1240. In terms of the effect they have on concrete pumping:

a) Fly ash (ASTM C618)—Pumpability is improved and water requirements are decreased due to the spherical-shaped particles acting as ball bearings, thereby providing a lubricant effect and reducing frictional losses during the pumping process

b) Slag cement (ASTM C989/C989M)—Pumpability is generally improved due to having lower specific gravity than cement, resulting in higher paste volume for a given cementitious content

c) Silica fume (ASTM C1240)—Pumpability is improved; however, water requirements are increased due to its finer particle size than cement yielding higher surface area required to be coated

There are three criteria that affect pumpability: 1) w/cm; 2) mortar volume; and 3) cementitious materials content. For effective and efficient pumping, the target ranges given in Table 4.1a may be used as a guideline to evaluate mixture pumpability. However, it should be noted that although these target values are applicable for most applications, there may be some cases that would fall outside of these recommended ranges and still achieve the desired pumpability. Therefore, these values may be taken as a starting point to evaluate pumpability and, if necessary, may be adjusted to accommodate a specific condition.

Values shown in Table 4.1b are taken from a practical example of a pumpable mixture specification.

CHAPTER 5—WATER

5.1—GeneralHistorically, normalweight concrete mixtures depend on

the water content of the mixture to determine the mixture’s pumpability. Typically, the w/cm is in the range of 0.40

to 0.60 for pumpable mixtures (Table 4.1b). However, excessive water in the mixture causes reduction in durability and strength. In such cases, the viscosity of the mortar will be lower than required to adequately suspend the coarse aggregate in the pump line with resulting segregation. If there is too little water in the mixture, the mortar volume will be insufficient enough to coat the coarse aggregate, provide relative aggregate movement, and create an adequate boundary layer to reduce friction near the interface between the concrete and wall of the pumping pipe.

Concrete mixture proportions have become more engineered and complicated with the increased use of admixtures and cementitious materials. As mixture variations are common, adjustments are sometimes made for specific properties in the aggregate, its grading, or both. An example of aggregate properties that require mixture adjustments is aggregate size or shape and amount of fine aggregates used.

CHAPTER 6—ADMIXTURES

6.1—GeneralACI 212.3R contains a general discussion of concrete

admixtures. Typically, any admixture that increases workability will usually improve pumpability. The type of admixture and advantages from its use in the concrete to be pumped depends on characteristics of the pump mixture and its components. When an admixture is selected to improve pumpability, it usually provides additional lubrication or reduces segregation.

6.2—Admixture types6.2.1 Normal, mid-range, and high-range water-reducing

admixtures—Most water-reducing admixtures increase

Table 4.1a—Check of sample mixture pumpabilityCriteria Actual Target Status

w/cm (by weight) 0.42 0.40 to 0.60 OK

Mortar volume, ft3 (m3) 15.63 (0.44) ≥12.1 (0.34) OK

Cementitious content, lb/yd3 (kg/m3) 555 (329) ≤400 (237) OK

Table 4.1b—Sample mixture used as an example to analyze pumpability

Material

Weight of material per cubic yard of concrete,

lb/yd3 (kg/m3)

Density of material, lb/ft3

(kg/m3)

Volume, ft3/yd3

(m3/m3)

Cement 500 (297) 196.56 (3150) 2.54 (0.094)

Fly ash 55 (33) 150.00 (2400) 0.37 (0.014)

Slag 0 181.00 (2900) 0.00

Silica fume 0 144.00 (2310) 0.00

Sand 1284 (762) 166.00 (2660) 7.73 (0.286)

Aggregate 1900 (1127) 168.00 (2690) 11.31 (0.419)

Water 235 (140) 62.4 (1000) 3.77 (0.140)

Water-reducing

admixture

4 fl. oz/cwt (260 mL/100 kg) 65 (1040) 0.06 (0.002)

Air, % 4 0 1.22 (0.045)

Total 3974 (2357) 27.00 (1.00)



--`,,`,`,,,,,````,``,,,,,,`,,,,-`-`,,`,,`,`,,`---



pumpability of the concrete mixture. Flowing concrete is useful for pumping because it allows greater movement of ingredients relative to each other, which is important when flowing through elbows and reducers. Reduction in pumping pressure increases both rate and distance that the concrete can be pumped. The addition of a high-range water-reducing admixtures (HRWRAs) may reduce pump pressures up to 35 percent for normalweight concrete, and by 10 to 20 percent for lightweight concrete (Kasami et al. 1979).

6.2.2 Air-entraining admixtures—As part of the pumping process, approximately 1 to 3 percent air loss may be expected; however, this air loss does not impact the freezing-and-thawing resistance as long as the air-void system is kept stable (Elkey et al. 1994). Mixtures with high initial air contents may be desired, as they are reported to provide a more stable air-void system when subjected to pump pressure (Dyer 1991). Therefore, air-entraining admixtures may improve pumpability due to increased air content, which in turn increases the paste volume. Air content should be selected by considering the durability, strength, and workability requirements.

6.2.3 Rheology and viscosity-modifying admixtures—These admixtures are used to increase cohesiveness of the mixture, which can provide for better finishing characteristic and improved pumpability. For pumpability, they reduce pumping pressure through improved lubricating properties and reduced segregation tendencies. For this reason, they are often used as pumping aids as well.

6.2.4 Extended set-control admixtures—These admixtures are used to stabilize freshly batched concrete to provide medium- to long-term set retardation. This allows concrete to remain plastic during long distance pumping, which requires a long slump life.

CHAPTER 7—FIBER REINFORCEMENTBoth steel and synthetic fiber-reinforced concrete can

be pumped. The fiber manufacturer’s literature and ACI 544.1R should be consulted to ensure proper application of fiber-concrete systems. Depending on fiber characteristics and volume, concrete mixture proportions, especially coarse aggregate volume, may need to be adjusted through consultation with the fiber supplier or concrete technology expert. To maintain the specified slump without increasing the w/cm, the addition of a mid-range water-reducing admixtures (MRWRAs) or HRWRAs is recommended. These slump adjustments can be made at the batch plant or job site, and will change as elevations or pump distances increase.

CHAPTER 8—TRIAL MIXTURES AND PUMPABILITY TESTING

It may be possible that the recommendations in this guide do not provide satisfactory assurance that the designed mixture proportions will meet the required pumpability characteristics. In such cases, trial mixtures should be prepared and tested with a pump and pump line configuration that is representative of the project requirements.

For lightweight concrete or fiber-reinforced concrete, it is recommended that the lightweight aggregate supplier or fiber supplier be consulted for the materials properties as well as

for recommendations on mixture proportions for pumping. It is also advisable to confer with the ready mixed concrete supplier to determine if storage and batching facilities are adequate to properly blend and saturate the materials.

CHAPTER 9—REFERENCESACI committee documents and documents published by

other organizations are listed first by document number, full title, and year of publication followed by authored documents listed alphabetically.

American Concrete InstituteACI 211.1-91(09)—Standard Practice for Selecting

Proportions for Normal, Heavyweight, and Mass ConcreteACI 211.2-98(04)—Standard Practice for Selecting

Proportions for Structural Lightweight ConcreteACI 212.3R-10—Report on Chemical Admixtures for

ConcreteACI 213R-14—Guide for Structural Lightweight-

Aggregate ConcreteACI 304R-00(09)—Guide for Measuring, Mixing,

Transporting, and Placing ConcreteACI 304.2R-17—Placing Concrete by Pumping MethodsACI 544.1R-96(09)—Report on Fiber Reinforced Concrete

ASTM InternationalASTM C29/C29M-17—Standard Test Method for Bulk

Density (Unit Weight) and Voids in AggregateASTM C33/C33M-18—Standard Specification for

Concrete AggregatesASTM C136/C136M-14—Standard Test Method for

Sieve Analysis of Fine and Coarse AggregatesASTM C150/C150M-18—Standard Specification for

Portland CementASTM C330/C330M-17—Standard Specification for

Lightweight Aggregates for Structural ConcreteASTM C595/C595M-18—Standard Specification for

Blended Hydraulic CementsASTM C618-17—Standard Specification for Coal Fly Ash

and Raw or Calcined Natural Pozzolan for Use in ConcreteASTM C989/C989M-18—Standard Specification for

Slag Cement for Use in Concrete and MortarsASTM C1157/C1157M-17—Standard Performance

Specification for Hydraulic CementASTM C1240-15—Standard Specification for Silica

Fume Used in Cementitious Mixtures

Authored documentsDyer, R. M., 1991, “An Investigation of Concrete Pumping

Pressure and the Effects on the Air Void System of Concrete,” master’s thesis, University of Washington, Seattle, WA.

Elkey, W.; Janssen, D. J.; and Hover, K. C., 1994, “Concrete Pumping Effects on Entrained Air-Voids,” Final Report, Research Project T9233, Task 21, Washington State Transportation Commission.

Kasami, H.; Ikeda, T.; and Yamane, S., 1979, “On Workability and Pumpability of Superplasticized Concrete-Experience in Japan,” Superplasticizers in Concrete, SP-62, American Concrete Institute, Farmington Hills, MI, pp. 21-36.



--`,,`,`,,,,,````,``,,,,,,`,,,,-`-`,,`,,`,`,,`---

https://www.concrete.org/

https://www.astm.org/

As ACI begins its second century of advancing concrete knowledge, its original chartered purpose remains “to provide a comradeship in finding the best ways to do concrete work of all kinds and in spreading knowledge.” In keeping with this purpose, ACI supports the following activities:

· Technical committees that produce consensus reports, guides, specifications, and codes.

· Spring and fall conventions to facilitate the work of its committees.

· Educational seminars that disseminate reliable information on concrete.

· Certification programs for personnel employed within the concrete industry.

· Student programs such as scholarships, internships, and competitions.

· Sponsoring and co-sponsoring international conferences and symposia.

· Formal coordination with several international concrete related societies.

· Periodicals: the ACI Structural Journal, Materials Journal, and Concrete International.

Benefits of membership include a subscription to Concrete International and to an ACI Journal. ACI members receive discounts of up to 40% on all ACI products and services, including documents, seminars and convention registration fees.

As a member of ACI, you join thousands of practitioners and professionals worldwide who share a commitment to maintain the highest industry standards for concrete technology, construction, and practices. In addition, ACI chapters provide opportunities for interaction of professionals and practitioners at a local level to discuss and share concrete knowledge and fellowship.

American Concrete Institute38800 Country Club DriveFarmington Hills, MI 48331Phone: +1.248.848.3700Fax: +1.248.848.3701

www.concrete.org



--`,,`,`,,,,,````,``,,,,,,`,,,,-`-`,,`,,`,`,,`---

http://www.concrete.org

38800 Country Club Drive

Farmington Hills, MI 48331 USA

+1.248.848.3700

www.concrete.org

The American Concrete Institute (ACI) is a leading authority and resource

worldwide for the development and distribution of consensus-based

standards and technical resources, educational programs, and certifications

for individuals and organizations involved in concrete design, construction,

and materials, who share a commitment to pursuing the best use of concrete.

Individuals interested in the activities of ACI are encouraged to explore the

ACI website for membership opportunities, committee activities, and a wide

variety of concrete resources. As a volunteer member-driven organization,

ACI invites partnerships and welcomes all concrete professionals who wish to

be part of a respected, connected, social group that provides an opportunity

for professional growth, networking and enjoyment.

9 781641 950282Copyright American Concrete Institute Provided by IHS Markit under license with ACI Licensee=http://www.GigaPaper.ir


--`,,`,`,,,,,````,``,,,,,,`,,,,-`-`,,`,,`,`,,`---

211.9r-18: guide to selecting proportions for pumpable concrete · 2020. 5. 12. · aci 211.9r-18...

Documents