Astm mnl 49 2014

D Gene Daniel and Colin L Lobo User’s Guide to ASTM Specification C94/C94M on Ready-Mixed Concrete: 2nd Edition ASTM Manual Series ASTM Stock Number: MNL49-2ND ASTM International 100 Barr Harbor Drive PO Box C700 West Conshohocken, PA 19428-2959 USA NRMCA National Ready Mixed Concrete Association 900 Spring Street Silver Spring, MD 20910, USA Printed in the U.S.A Library of Congress Cataloging-in-Publication Data Daniel, D Gene, 1934 [User’s guide to ASTM specification C94 on ready-mixed concrete]  User’s guide to ASTM specification C94/C94M on ready-mixed concrete / D Gene Daniel, Colin L Lobo 2nd edition   pages cm  Revised edition of: User’s guide to ASTM specification C94 on ready-mixed concrete / D Gene Daniel and Colin L Lobo 2005  Includes bibliographical references and index  ISBN 978-0-8031-7054-4 (alk paper) Ready-mixed concrete–Specifications–United States I Lobo, Colin L., 1961- II Title  TA439.D25 2013  666’.893–dc23 2013041858 Copyright © 2014 ASTM International, West Conshohocken, PA All rights reserved This material may not be reproduced or copied, in whole or in part, in any printed, mechanical, elec­tronic, film, or other distribution and storage media, without the written consent of the publisher Photocopy Rights Authorization to photocopy items for internal, personal, or educational classroom use of specific clients, is granted by ASTM International provided that the appropriate fee is paid to ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, Tel: 610-834-9634; online: http://www.astm.org/copyright/ ASTM International is not responsible, as a body, for the statements and opinions advanced in the publication ASTM International does not endorse any products represented in this publication ASTM International 100 Barr Harbor Drive PO Box C700 West Conshohocken, PA 19428-2959, USA Phone: (610) 832-9585 Fax: (610) 832-9555 E-mail: service@astm.org Website: www.astm.org ISBN 0-8031-3363-4 ASTM Stock Number: MNL 49-2ND NRMCA National Ready Mixed Concrete Association 900 Spring Street Silver Spring, MD 20910, USA Phone: (301) 587-1400 Fax: (310) 585-4219 E-mail: publications@nrmca.org Website: www.nrmca.org NRMCA Order Number: 2PMNL 49 Printed in Mayfield, PA May, 2014 iii Foreword This publication, User’s Guide to ASTM Specification C94/C94M on Ready-Mixed Concrete, was co-published by ASTM International and the National Ready Mixed Concrete Association (NRMCA) It was both authored and edited by D Gene Daniel, concrete consultant, Claremore, Oklahoma; and Colin L Lobo, National Ready Mixed Concrete Association, Silver Spring, Maryland This publication was sponsored by Committee C09 on Concrete and Concrete Aggregates and it is the second edition of Manual 49 of ASTM’s manual series v Contents Preface vii Introduction xi Scope 1 Referenced Documents 5 Terminology 7 Basis of Purchase 11 Materials 17 Ordering Information 41 Tolerances in Slump or Slump Flow 55 Air-Entrained Concrete 61 Measuring Materials 69 10 Batching Plant 81 11 Mixers and Agitators 91 12 Mixing and Delivery 101 13 Use of Nonagitating Equipment 121 14 Batch Ticket Information 123 15 Plant Inspection 129 16 Practices, Test Methods, and Reporting 131 17 Sampling and Testing Fresh Concrete 141 18 Strength 149 19 Failure to Meet Strength Requirements 159 20 Keywords 163 21 Annex A1 Concrete Uniformity Requirements (Mandatory Information) 165 22 Appendix (Nonmandatory Information) 171 Index 179 vii Preface What is ASTM? To fully understand ASTM C94/C94M, Specification on Ready- Mixed Concrete, it is necessary to understand ASTM and the consensus process for developing standards such as ASTM C94/ C94M Getting a view of ASTM from its conception takes us back more than a century The time period involved is between the American Civil War, which ended in 1865, and World War I, which began in 1914 The true beginning of ASTM coincided with the Spanish-American War fought in 1898 The world, and more specifically the United States, was in the midst of the second phase of the Industrial Revolution Major advances in communication and transportation were taking place in a country that in the late 1890s consisted of 45 states The diesel engine, electrical power, and the steel industry were all coming into prominence The United States was a growing, developing, and prosperous nation with industrial corporations, some of which have gone on to grow into giants that remain today William McKinley was elected President in 1896, re-elected in 1900, and assassinated in 1901 This growth period and the industrial revolution were the backdrop that fostered ASTM The North American railroad network was expanding in all directions less than 30 years after the completion of the first transcontinental railroad Charles Dudley, holder of a Ph.D from Yale University, was a chemist for the Pennsylvania Railroad Mr Dudley’s degree preceded by two years Custer’s Last Stand at the Battle of the Little Big Horn in the hills of Montana A portion of Mr Dudley’s duties included doing research to develop more durable steel for use as rails and writing a specification conveying those findings to the rail manufacturers Mr Dudley’s ideas did not always coincide with those of the steel manufacturers or the other railroads that were buying steel rails These problems of differing viewpoints led to the first meetings of manufacturers, chemists, engineers, and others in the steel and railroad or bridge business to develop standards everyone could tolerate The idea that emerged was that good material standards require the input of manufacturers, designers, builders, and users This was the idea in June of 1898 when ASTM was first formed under another name, American Section of the International Association for Testing Materials From the first meeting, the goal was to develop consensus standards The first committee dealing with cement, C01, was formed in 1902, and the concrete and concrete aggregates committee, C09, formed in 1914 The scope of ASTM has continued to expand, and its name has continued to change The name today is ASTM International, reflecting both its wide use and a broad international membership From the original 70 members, ASTM International (ASTM) has grown to more than 30,000 members For the 100 plus years of its existence, the committee work has remained in the hands of volunteers What is Subcommittee C09.40? At the bottom of the first page of the document ASTM Standard Specification for Ready-Mixed Concrete (C94/C94M) is a notation: “This specification is under the jurisdiction of ASTM Committee C09 on Concrete and Concrete Aggregates and is the direct responsibility of Subcommittee C09.40 on ReadyMixed Concrete.” Very simply, Subcommittee C09.40 is the group of people who the actual writing of ASTM C94/C94M This subcommittee is typically composed of approximately 100 people, including manufacturers of ready-mixed concrete, private engineers from design firms and material testing firms, state highway department engineers, representatives of federal agencies, representatives of trade organizations, professors from foreign and domestic universities, contractors, and representatives from concrete material producers, such as cement and chemical admixtures, as well as others who have a relationship to the industry Most of these people are engineers or scientists whose daily activities involve them with the concrete industry Most, but not all, live in the United States Subcommittee C09.40 is only one of many subcommittees that function as a part of the Committee C09 on Concrete and Concrete Aggregates The main body of Committee C09 divides into approximately 29 subcommittees to develop consensus standards for the concrete and concrete aggregates industry viii User’s Guide to ASTM Specification C94 on Ready-Mixed Concrete ASTM Standards Development Process ASTM standards development follows a consensus process consistent with requirements of the American National Standards Institute (ANSI) ANSI facilitates the development of American National Standards (ANS) by accrediting the procedures of standards developing organizations (SDOs) like ASTM International SDOs work cooperatively to develop voluntary national consensus standards An important requirement is to ensure the voting producer representation on the committee is balanced between voting representation by users and by general interest members Each company or entity is assigned one vote, and additional representatives from that entity are provided a nonvoting status This ensures that the interests of one particular group not bias the development of the standard and that all viewpoints are addressed The development of standards through consensus requires time and compromise but ensures, for the most part, that the standards developed satisfy all affected groups American National Standards development process is usually referred to as “open” standards development In this sense, “open” refers to a process used by a recognized body for developing and approving a standard This ensures a collaborative, balanced, and consensus-based approval process The content of these standards may relate to products, processes, services, systems, or personnel New standards or revisions to existing standards within ASTM usually begin within a task group of a subcommittee The task group develops a written ballot that is submitted for letter ballot to the subcommittee Reviewing subcommittee ballots and voting is both a privilege and a responsibility of committee membership When a subcommittee member casts a negative vote on a ballot item, an explanation of what the voter objects to and what changes could be made to satisfy the concerns of the negative voter is required For a ballot to become valid, at least 60 % of the voting subcommittee members must have voted For a ballot item to be successful, two thirds of the eligible voting members must vote affirmatively on a ballot item To advance to the next level, the subcommittee vote must be positive for two thirds or more of those voting In reality, each negative vote of a member, voting or nonvoting, is vetted, or the ballot item withdrawn and revised, if possible, into a new subcommittee ballot The item is then either re-balloted at the subcommittee level, or with the approval of the committee chairman the revised item may be balloted concurrently at both the subcommittee and committee levels The committee level involves all the members of the various subcommittees In the case of the Committee C09 this involves approximately 29 subcommittees and 700 members Committee C09 meets in June and December each year with a usual attendance of 150 to 200 members It is at these semiannual meetings that each negative ballot is vetted and voted on At the committee level a ballot item must receive affirmative votes on at least 90 % of the votes cast for approval If approved at the committee level, the balloted item is approaching ASTM membership approval Simultaneously with the committee level vote, the proposed change is also subject to a vote by the entire ASTM Society, which includes all the ASTM members in various committees No voting percentages are required at this level, but negative votes must again be considered The consensus system also provides for an appeal by a negative voter The appeals system varies depending upon the grounds stated for the appeal A Committee on Standards assures that due process is followed The primary point of the entire process is that each negative voter’s voice and arguments are heard, and the subcommittee or committee is then afforded the opportunity to vote on an issue based on the thoughts and reasoning of one member of the group A single objection often influences others and alters the content of a proposal or kills the proposal completely ASTM firmly believes in the old adage that two heads are better than one and has set up a system to ensure that each member’s voice is heard Original ASTM Specification for Ready-Mixed Concrete The original C-9 (now C09) committee required six years (1914–1920) to issue its first standard The first standard addressed the proper means of molding and storing concrete cylinders in the field and described methods still in use today The first product specification was issued in 1933 as a tentative specification for ready-mixed concrete The topics covered did not vary much from today’s standard, over 75 years later The specification has been revised many times since approved in 1935 and continues to undergo revisions to remain in step with technological advances, such as load-cell weighing, and environmental issues, such as limiting plant runoff water by the use of non-potable water in the batching process The roots of a successful specification go back to the abilities of the committee who prior to 1933 published a comprehensive document prescribing the materials, proportioning, mixing, delivery, quality, inspection, testing, and acceptance of ready-mixed concrete for delivery to the job site ready for use An equivalent specification to ASTM C94/C94M is published by the American Association of State Highway and Transportation Officials (AASHTO) M 157 Standard Specification for Ready-Mixed Concrete As the association name implies, this organization includes representatives from each state and some other entities involved in construction of transportation infrastructure Development of AASHTO standards does not follow the typical consensus process because AASHTO limits voting interests to designers and users (state departments of transportation) and excludes industry representation AASHTO Subcommittee on Materials reviews changes to ASTM standards and chooses to ballot these changes to the AASHTO standards Some AASHTO standards are Preface essentially very similar to ASTM standards AASHTO M 157 is structured slightly differently than ASTM C94/C94M, but the technical differences are relatively minor There are several sections of ASTM C94/C94M that are not covered in AASHTO M 157 The greatest difference between the two specifications is in the category of ordering information ASTM C94/C94M has three options, providing more latitude to the purchaser AASHTO M 157 does not provide a section on ordering Instead ASSHTO M 157 has a quality of concrete section that concerns submittals to the engineer by the contractor or the proportioning prescribed by the engineer and directed to the contractor Another difference between the two sets of standards is in the reference to the use of mixing water in concrete ASTM C94/ C94M references ASTM C1602 A note at the end of AASHTO M 157 recognizes these differences and suggests, “users other than specifying agencies should consider ASTM C94.” State highway agencies vary in their reference to ASTM or AASHTO standards How to Use ASTM C94/C94M The most common usage of ASTM C94/C94M is as a reference document within a design professional’s specification for castin-place concrete A statement such as “Unless otherwise specified, use materials, measure, batch, and mix concrete materials and concrete and deliver concrete in approved equipment, all in conformance with ASTM C94/C94M” within the concrete specifications for a project specify the strength, slump, air content, aggregate size, and other variable factors named in Section 6, Ordering Information, will be provided Other methods are suitable if the questions in Ordering Information are answered A purchase order with a ready-mix concrete manufacturer may simply state “Produce and deliver concrete as per C94.” An important violation that can cause trouble is using excerpts from ASTM C94/C94M or any other specification without a careful reading of the entire document for related segments Unfortunately some design professionals follow this cut and paste style It is best to use the complete document by reference How to Use this Guide The chapters in this book reflect the sections of C94/C94M Text from C94/C94M is reproduced in italicized text followed by a discussion of the section Sentences in the specification are cross-referenced and discussed in the text with identifications S1, S2, etc Tables, figures, and numerical examples are numbered sequentially by chapter number, except for tables excerpted from C94/C94M, which retain the actual table number from C94/C94M Disclaimer This book represents the interpretation of the authors concerning ASTM C94/C94M and does not represent the views of ASTM International or Subcommittee C09.40 ix APPENDIX (Nonmandatory Information) FIG 22.A Frequency distribution of 100 strength test results Frequency Distribution 20 18 14 15 12 10 7 4400 4200 4000 3800 3600 3400 3200 3000 2800 2600 2400 2200 4800 4600 Number of Tests 16 Compressive Strength, psi • The spread of the curve is characterized by the standard deviation The greater the spread, the higher the standard deviation (or greater the variability) • Statistical theory can be used to predict the percentage of tests within (or outside) a particular range If the total area under the curve represents 100 % of the results, a portion of that area is proportional to the number of tests within that range For example, if the area under the bell curve in Fig 22.B on the right of 4000 psi is 20 %, then statistical theory indicates that 20 % of the test results will be higher than 4000 psi The normal distribution curve is defined by the mean (average) test value and the standard deviation The abscissa (x-axis) in this case is the strength The ordinate (y-axis) is the FIG 22.B Normal distribution curve for strength test results number of tests in each range The referenced horizontal distance is measured in units of standard deviation, denoted by σ (sigma) The multiplier to σ is identified as z Thus, zσ defines a horizontal distance from the mean in terms of number of standard deviations The proportion of area under the curve between the mean and a point zσ defines the percentage of tests expected to lie in that defined area For example at the point + 1.0 σ the area under the curve between the mean and that line represents 34.13 % of the total area To estimate the percentage of strength tests within a range of ± σ about the mean, this would be × 34.13 % = 68.26 % Other values for percentage of tests for different commonly used values of z are provided in Table 22.A The second column of Table 22.A estimates the total percentage of tests between zσ and +zσ The portion of tests falling below or above that value of zσ equals one-half of the portion outside the prescribed limits For z = 1.64, 90 % of the test results fall within ± 1.64 σ about the mean, and % will be greater than + 1.64 σ, while % will be less than − 1.64 σ A distinction is included here between statistical nomenclature and concrete test values through the following definitions: σ (sigma) = the standard deviation for the entire population of possible test results s (lowercase) = the sample standard deviation for the data set that is an estimate of the standard deviation of the population of strength tests Table 22.A can be used to illustrate the impossible situation set by the specification clause mentioned earlier If the specification requires 100 % of all tests to be greater than the specified compressive strength, the strength level for which the mixture has to be designed will be significantly high to avoid the 173 174 User’s Guide to ASTM Specification C94 on Ready-Mixed Concrete TABLE 22.A Percent of Tests (rounded off) at Different Levels of “zσ” z Percent of Tests Within ±zσ Percent of Tests Less Than – X - zσ 0.84 60 20 in 1.00 68 16 in 6.3 in 10 1.28 80 10 1.34 82 in 11 1.64 90 in 20 1.96 95 2.5 in 40 2.00 95.5 2.25 in 44 2.33 98 1.00 in 100 3.00 99.8 0.10 in 1000 4.00 99.98 0.01 in 5000 possibility of one failing test If ƒ´c is 4000 psi and the standard deviation is 600 psi, a concrete mixture proportioned to produce an average strength of 4000 + (2.33 × 600) = 5400 psi will have a 1.0 % probability of a failing test result To approach a % probability of failure the mixture should achieve an average strength of 4000 + (4.0 × 600) = 6400 psi The impact of this type of a specification clause should be brought to the attention of the specifier so an opportunity is provided for a correction Another point to note regarding the variability of strength test results is that the standard deviation increases as the average strength increases [3] It is therefore not useful to look at standard deviation in isolation without reference to the mean or average value of the data set The standard deviation should not be compared when the mean and average are significantly different For these purposes, the coefficient of variation, V, is sometimes used The coefficient of variation is the standard deviation expressed as a percentage of the average Variability of two sets of data with significant different averages or means can be compared using the coefficient of variation X1.1 S1 Section 18.4 of this specification contains the same strength requirements as those contained in ACI 318 and ACI 301, except it does not require the submittal of the data and calculation of the average strength, ƒ´cr necessary to meet those ACI Code and Specifications.  S2 This Appendix does not include all of the detailed requirements of the ACI Code and Specification that will govern a submittal for their respective purposes.  S3 The following material is intended to guide users of this specification when no formal submittal is required S1 and S2 are reminders that ASTM C94/C94M has established in Section 18.4 that strength requirements of this specification mirror those of ACI 318 and ACI 301 and are applicable unless the project specifications state alternative test acceptance criteria It also points out that C94/C94M does not require any submittal documenting how the required average strength is determined, the mixture proportions, or submittal of strength tests associated with the proposed mixture The purchaser can request information on the mixture proportions or any other information, as addressed in Section 6, and the manufacturer is obliged to provide that information Detailed discussion on the submittal requirements of ACI 318 and ACI 301 are not presented here It should be pointed out that ACI 301 is not required to exactly follow ACI 318, only that it be at least as conservative as ACI 318 In fact, there are some differences, and ACI 301 is more conservative than ACI 318 for its strength submittal requirements S3 declares that the information within this Appendix is intended as only a guide to users when no formal submittal is required This is consistent in that an Appendix to an ASTM standard contains only nonmandatory and advisory information Section 18.4, however, states the acceptance criteria for concrete strength is a mandatory requirement in the event over-riding concrete acceptance criteria are not a part of the specifications for a project A project specification that references ASTM C94/C94M includes the requirements of Section 18.4 by default The over-design for strength presented in this Appendix reduces the risk for a manufacturer to meet these acceptance criteria It should also be noted that ASTM C94/ C94M is adopted by reference in the ACI 318 Building Code There is no conflict because the acceptance criteria are the same X1.1.1 S1 Table X1.1 provides the statistical formulas that can be used to calculate the required average strength ƒ´cr when historical statistical data are available.  S2 The formula to achieve a satisfactory average of three consecutive strength tests as required in 18.4.1 is (Eq X1.1) of Table X1.1.  S3 The formulas for the minimum strength of an individual strength test result as required in 18.4.2 and 18.4.3 are (Eq X1.2) and (Eq X1.3) in Table X1.1.  S4 Since the average strength, ƒ´cr , must be high enough to conform to both averages of three consecutive tests and the requirements on minimum strength of a test, the one which requires highest average strength (ƒ´cr ) governs S1 refers to the Table X1.1 that contains the ACI 318 [1] formulas used to calculate the required average strength (ƒ´cr ) for a concrete mixture based on the specified compressive strength (ƒ´c ) Table X1.1 addresses the situation when there is a strength test record on a similar mixture produced from the concrete plant from which a standard deviation can be calculated The standard deviation established from the strength test record from prior projects represents the level of concrete quality produced by the plant In ACI standards, it suggests that the standard deviation should represent mixtures of the similar type and produced under similar conditions For the mixture type, it says that the specified strength for the test record and the proposed project APPENDIX (Nonmandatory Information) TABLE X1.1 Required Average Compressive Strength when Data are Available to Establish a Standard Deviation Inch-pound System SI System Specified Strength Required Average Strength Specified Strength Required Average Strength f ′ c , psi f ′cr , psi f ′ c , MPa f ′ cr , MPa f ′c equal to Use the larger from   f ′c equal to Use the larger from   or less than 5000 Eq X1.1 and X1.2   or less than 35 Eq X1.1 and X1.2m   f ′cr = f ′ c + 1.34s (X1.1)  f ′cr = f ′ c + 1.34s (X1.1)  f ′cr = f ′c + 2.33s – 500 (X1.2) f ′cr = f ′c + 2.33s – 3.45 (X1.2m) Use the larger from   Use the larger from   Eq X1.1 and X1.3   Eq X1.1 and X1.3   f ′cr = f ′ c + 1.34s (X1.1)  f ′cr = f ′ c + 1.34s (X1.1)  f ′cr = 0.90f ′c + 2.33s (X1.3) f ′cr = 0.90f ′c + 2.33s (X1.3) greater than 5000 greater than 35 where: f ′ c = the specified compressive strength, f ′cr = the required average compressive strength s = the standard deviation should be within 1000 psi This is addressed in Section X1.1.2 Similar conditions can have a subjective interpretation It may not mean concrete produced at the same plant If the concrete was furnished from two plants with the same materials and similar batch plant set up and with the same testing agency involved, this can be considered similar If a test record represents non-air-entrained concrete, it is not appropriate to use that for an air-entrained concrete mixture even at the same strength level Producing air-entrained concrete tends to be more variable It is important to recognize that the standard deviation determined and the over-design strength established serves to protect the manufacturer and the purchaser The manufacturer reduces the risk of failing the acceptance criteria with proper use of these concepts The purchaser is ensured that there is improved probability that the concrete furnished for the work will be what is needed by the design Neither Section 18 nor this Appendix actually state that mixture proportions be established to the ACI 318 requirements The formulas of Table A1.1 are the same as the ACI formulas, but without a reference the other requirements are not applicable The other details involve the age of a test record, combining two groups of tests, and other specific details are not addressed in this Appendix Good judgment is primarily implied S2 and S3 state the basis for the over-design on strength The concrete manufacturer sets the target strength of the proposed concrete mixture such that there is less than a % probability of failing the acceptance criteria in Section 18.4 The equations in Table X1.1 are directly linked to the criteria in Section 18.4 The assumption is that the same standard deviation (variability) assumed will be applicable for the upcoming project, and that the average strength level of test results during the project will be maintained at the required average strength (ƒ´cr ) This is not a requirement, just an assumption, and this is the situation in which the concepts of the normal distribution of strength test results are put to practice This applies only when a standard deviation from a strength test record of a similar concrete mixture can be established The first acceptance criterion (see Section 18.4.1) is that the average of three consecutive strength test results should be equal to or exceed the specified strength (ƒ´c ) Equation X1.1 is related to this criterion The z-value of 1.34 is derived from the % probability of failure in Table 22.A of 2.33 Since three consecutive tests are included, 1.34 is derived from (2.33/√3) So equation X1.1 indicates that the mixture should be overdesigned by a strength of 1.34 times the standard deviation greater than the specified strength [7] If the criteria was such that it was stated on the basis of five tests, the z-value would have been (2.33/√5 = 1.04) The second acceptance criterion (see Section 18.4.2) states that no individual strength test should be more than 500 psi below the specified strength, when the specified strength is 5000 psi or less Equation X1.2 is related to this criterion The z-value selected is 2.33 and sets the 1 % probability of failing this acceptance criterion The required average strength of the concrete mixture is designed for an over-design strength of 2.33 times the standard deviation greater than (ƒ´c – 500) psi When the specified strength is greater than 5000 psi, the acceptance criterion (see Section 18.4.3) states that no individual strength should be less than (0.90 ƒ´c ) Equation X1.3 is related to this acceptance criterion The required average strength of the concrete mixture is designed for an over-design strength of 2.33 times the standard deviation greater than 0.90 ƒ´c From the values obtained from the two equations, the higher value is selected for the required average strength This is stated in S4 The concrete mixture is proportioned to 175 176 User’s Guide to ASTM Specification C94 on Ready-Mixed Concrete achieve an average strength of this required average strength (ƒ´cr ) or higher For equations X1.1 and X1.2 they converge to the same value of ƒ´cr when the standard deviation is 505 psi If the standard deviation is less than 505 psi, equation X1.1 gives the value of ƒ´cr If the standard deviation is greater than 505 psi, equation X1.2 gives the value of ƒ´cr When concrete mixtures are designed to this level, and the operational and testing variability is the same as assumed, the probability of failing the acceptance criteria in Section 18.4 is % or a in 100 probability Section 18.4 establishes two acceptance criteria for concrete strength The second one for individual strength test results depends on the specified strength Both these criteria must be met X1.1.2 S1 The first step in the process of calculating the overdesign above ƒ´c or the required average strength is to determine if a record of 30 consecutive tests is available for the proposed mixture or similar mixture with a design strength within 1000 psi [6.6 MPa] of the specified compressive strength proposed for use.  S2 If it is a new mixture or strength level and no standard deviation data is available then Table X1.2 provides default levels of over-design equal to 1000, 1200, or (1.10 ƒ´c + 700) psi S1 addresses two aspects The first aspect indicates that the standard deviation should be calculated from a test record that is comprised of at least 30 consecutive tests The second aspect indicates that the test record should be from a similar mixture where the strength should be within 1000 psi of the specified strength of the project under consideration What is unclear in this is the term design strength It is presumed to mean specified strength for the project represented by the strength test record This discussion on the requirements for the strength test record was discussed under Section X1.1.1 The requirement for 30 tests is from the ACI standards [1,2] It is felt that 30 tests is a reasonable minimum number to obtain a good estimate of the standard deviation The tests should also not be collected from one or two days of production because the variability will be less and probably not representative of what happens over the duration of a project that can last through changing seasons and several changing material shipments The ACI standards permit two test records to be pooled to calculate an average standard deviation if the total number of tests is at least 30 Accumulating 30 test results from two mixes is often a burden for plants in more rural areas, considering the volume of concrete that might be tested Utilizing more than two sets of test records to achieve the pooled standard deviation is not prohibited by C94/C94M and is often the only solution available in situations when there are a smaller number of acceptance tests on typical mixtures for each project If the total number of tests is greater than 15 and fewer than 30, these standards also provide some multipliers to increase the standard deviation because there is a higher uncertainty of the estimate of the standard deviation with a smaller number of tests If there are fewer than 15 tests for a test record, the standard deviation basis for determining the required average strength cannot be used on a project subject to ACI 318, and Table X1.2 would apply S2 is a direction to use the over-design values of Table X1.2 if the strength test records are not available to calculate a standard deviation These Table X1.2 values are suggested for use to be more conservative with the strength level furnished because the variability of the production facility cannot be quantified If standard deviation of a facility is greater than around 650 psi, the values in Table X1.2 will result in a lower over-design than that determined using the standard deviation ACI 214R-11 [3] describes a 650 psi standard deviation as a fair standard of control and 700 psi or greater as a poor standard of control Appendix X1.1 does not suggest a limit on the age of the test record as does ACI 318, which states that the test record should be less than 24 months old The concrete manufacturer should use the most accurate data available considering the quality constants or changes in materials and the systems in place for quality control While this Appendix does not address submittals, the next part is to document to the purchaser (the designer) that the proposed mixture can achieve the required average strength, ƒ´cr , or greater This can be done by using a strength test record from TABLE X1.2 Required Average Compressive Strength When Data Are Not Available to Establish a Standard Deviation Inch-pound System Specified Strength, f ′c , psi SI System Required Average Strength f ′cr, psi Specified Strength, f ′c , MPa Required Average Strength f ′ cr , MPa Less than 3000 f ′c + 1000 Less than 21 f ′c + 7.0 3000 to 5000 f ′c + 1200 21 to 35 f ′c + 8.5 greater than 5000 1.10f ′c + 700 greater than 35 1.10f ′c + 5.0 where: f ′c = f ′cr = s = the specified compressive strength the required average compressive strength the standard deviation APPENDIX (Nonmandatory Information) a previous project; the same test record used to calculate the standard deviation can be used, or laboratory trial batches can be performed to document the strength and other properties of the concrete mixture Interpolation is permitted between strength levels with different mixture proportions, typically varying cement content or w/cm X1.1.3 S1 Table X1.3 provides calculated values of over-design and required average strength for selected standard deviations and specified strength levels.  S2 Because of the large ranges of strength and standard deviations, the gray shaded areas are considered unusual or not likely to be encountered Table X1.3 provides calculations of the over-design and average strengths arrived at from the previous sections The upper half of the table provides the over-design necessary based on the specified strength (ƒ´c ) and the plant’s standard deviation from a strength test record For example if the plant’s standard deviation is 700 psi and the project’s specified strength is 3000 psi the formulas of Table X1.1 calculate a needed over-design of 1131 psi The lower segment of the table adds the over-design (1131 psi) to the specified strength and displays the required average strength, which in this instance is 4131 psi Several areas are shaded in Table X1.3 because the standard deviations are considered either unusual or inappropriate It is considered unusual to obtain a very low standard deviation in the range of 300 to 500 psi when producing concrete strengths at 10,000 psi and higher On the other side, very high standard deviation for lower strength concrete is generally indicative of a very low level of quality control Using the fixed overdesign values from Table X1.2 will result in a lower value of required average strength However, if the real variability of the producer is high as indicative of the high standard deviation, the risk of failing the strength acceptance criteria increases The following chart (Example 22.B) of sample calculations demonstrates the method of the development of Table X1.3 from the formulas of Table X1.1 TABLE X1.3 Over-design Necessary to Conform to Specified Compressive Strength* Required Over Design–Inch-Pound Units ƒ ′c , psi Specified Standard Deviation from field data 300 500 700       3,000 402 670 1,131 1,100 unknown     ƒ ′c + 1000 1,597 2,063 1,200 Over design above ƒ ′c Strength less than 3000 no SD data 900 5,000 402 670 1,131 1,597 2,063 1,200 7,000 402 670 938 1,397 1,863 1,400 9,000 402 670 938 1,206 1,663 1,600 11,000 402 670 938 1,206 1,474 1,800 13,000 402 670 938 1,206 1,474 2,000 15,000 402 670 938 1,206 1,474 2,200 17,000 402 670 938 1,206 1,474 2,400 Required Average Strength–Inch-Pound Units ƒ ′c , psi Specified Standard Deviation from field data 300 500       no SD data 900 1,100 unknown     ƒ ′c + 1000 4,200 ƒ ′cr , Required Average Strength, psi Strength less than 3000 700 3,000 3,402 3,670 4,131 4,597 5,063 5,000 5,402 5,670 6,131 6,597 7,063 6,200 7,000 7,402 7,670 7,938 8,397 8,863 8,400 9,000 9,402 9,670 9,938 10,206 10,663 10,600 11,000 11,402 11,670 11,938 12,206 12,474 12,800 15,000 13,000 13,402 13,670 13,938 14,206 14,474 15,000 15,402 15,670 15,938 16,206 16,474 17,200 17,000 17,402 17,670 17,938 18,206 18,474 19,400   * Shaded Areas identify levels of specified strength where the standard deviation should be considered unusual or inappropriate Only inch-pound units part of table X1.3 from C94/C94M is reproduced here 177 178 User’s Guide to ASTM Specification C94 on Ready-Mixed Concrete Example 22.B Over-design calculations Specified Strength, ƒ´c Formula X1.1 Formula X1.2 Formula X1.3 Standard Deviation (s) 1.34 s 2.33s – 500 2.33 s – 0.1 ƒ´c 500 500 500 300 700 700 700 unknown unknown 900 670 670 670 402 938 938 938 … … 1206 665 … … 199 1131 1131 … … … … 665 465 … 931 … … … 1397 3000 5000 7000 4000 5000 7000 3000 5000 6000 7000 Table X1.2 … … … … … … … 1200 1300A … 0.10 ƒ´c + 700 Bold = control for the set of values A The formula (ƒ´cr = 0.90 ƒ´c + 2.33s) is represented differently for formula X1.3 for over-design value and indicated as (2.33s – 0.10 ƒ´c ) when ƒ´c is greater than 5000 psi [4] Chung, H W., “How Good is Good Enough—A Dilemma in Acceptance Testing of Concrete,” ACI Journal Proceedings, Vol 75, No 8, Aug 1978, pp 374–380 References [5] Mathews, D H and Metcalf, J B., “The Specification of Concrete Strength, Part III The Design of Acceptance Criteria for the Strength of Concrete,” RRL Report LR 301, Road Research Laboratory, Crowthorne, Berkshire, 1970, pp 1–11 [1] ACI Committee 318, “Building Code Requirements for Structural Concrete and Commentary,” ACI 318-11, American Concrete Institute, Farmington Hills, MI, 2011, pp 65–76 [2] ACI Committee 301, “Specification for Structural Concrete,” ACI 301-10, American Concrete Institute, Farmington Hills, MI, 2010, pp 12–24 [3] ACI Committee 214, “Guide to Evaluation of Strength Test Results of Concrete,” ACI 214R–11, American Concrete Institute, Farmington Hills, MI, 2011, pp 7–12 [6] Obla, K H., “Concrete Quality Series, Parts – 15, Concrete InFocus,” National Ready Mixed Concrete Association, May 2010–Summer 2013, www.nrmca.org [7] ACI Committee 214, “Evaluation of Strength Test Results of Concrete,” ACI 214R-02, American Concrete Institute, Farmington Hills, MI, 2002, pp 10–11 179 Index A “A plus” ordering option, 45 accelerating admixtures (Type C), 35–36 acceptance criteria, strength testing, 171–178 accuracy meter, 114 scale, 84–88, 89–90 ACI 211.1, (table), 43, 45, 48, 74 ACI 211.2, (table), 48 ACI 214R-11, 151 ACI 225R-99, 19 ACI 228.1R-03, 155 ACI 301, 2, (table), 47, 77, 156 See also ACI 301-10 ACI 301-10, 2, 28, 50, 53, 145 See also ACI 301 ACI 305R, (table) ACI 306R, (table), 115 ACI 318 Building Code, 154, 155, 157, 171 ACI 318, (table), 49, 54, 77, 132 See also ACI 318-11 ACI 318-11, 2, 44, 145, 146, 152, 154, 155, 156, 157, 171, 174 See also ACI 318 ACI 350, 53 See also ACI 350-06 ACI 350-06, 44, 145 See also ACI 350 ACI Concrete Laboratory Testing Technician—Grade I, 150 added water, 88, 125 See also water admixture dispenser on weight basis, 79 (figure) admixtures, 24, 35–37 air-entrained, 25, 34–35, 104, 167 chemical, 35–37, 43, 74, 76–78 fiber, 76 liquid, 77–78 mineral, 24, 69, 126–127 purchaser specifications, 51–52 See also specific admixtures aggregate feed system, 82–83 aggregates, 27–29 alkali-reactive, 19, 28 batch tickets and, 127–128 in cold weather, 116 mass, 72, 82–83 measurement and, 72–73 proportioning, 45 reactivity evaluation, 28 storage, 81–84 See also course aggregates; lightweight aggregates agitators, 91, 93, 94–95, 97–99 air content, 11 check test, 147–148 losses, 64–65 point of discharge and, 44 (table) test methods and, 133–135 test reports and, 50 tests, 61–62, 64–65, 67 tolerance and, 63–67 uniformity tests and, 167 values, 62–63 air content tests, 61–62, 64–65, 67, 147–148 air detrainer, 37 air entrainment, 23 See also air-entrained admixtures (AEA); air-entrained concrete air-dry mass, 47 air-entrained admixtures (AEA), 34–35 fly ash and, 25 mixing time, 104 uniformity tests and, 167 air-entrained concrete, 43–45, 61–67, 175 air-entrained portland cement, 21 air-free mortar, 168–169 air proportions, 18 (figure) alkali oxide, 19 alkali-reactive aggregate, 19 alkali-silica reactivity (ASR) requirements, alumina (Al2O3), 18 American Association of State Highway and Transportation Officials (AASHTO), 19 Annex A1, 122, 165–170 anti-washout admixtures, 37 180 User’s Guide to ASTM Specification C94 on Ready-Mixed Concrete arbitration, low strength test and, 159–161 architect/engineer (A/E) firms, 53, 63 See also purchaser architectural concrete, 43 asphalt production, 81 ASTM C29/C29M, 12, 13 ASTM C31/C31M, (table), 48, 131, 149, 152 ASTM C33/C33M, 2, (table), 19, 27, 29, 50 ASTM C39/C39M, (table), 132, 151, 154 ASTM C42/C42M, 155 ASTM C70, 127 ASTM C78/C78M, 153 ASTM C88, 28 ASTM C125, (table) ASTM C138/C138M, (table), 11, 12, 13, 15, 46, 47, 66, 132–134, 149, 167, 611 ASTM C143/C143M, (table), 55, 56, 135, 149 ASTM C150/C150M, (table), 17, 19–21, 50, 51, 69, 71–72 ASTM C172/C172M, (table), 12–13, 64, 108, 136–137, 143–144, 146, 149, 167 ASTM C173/C173M, (table), 61, 149 ASTM C219, 18 ASTM C231/C231M, (table), 12, 13, 61, 65, 133–134, 135 (figure), 149 ASTM C260/C260M, (table), 34–35, 50, 52 ASTM C293/C293M, 153 ASTM C330/C330M, (table), 50 ASTM C457/457M, 65 ASTM C494/C494M, (table), 50, 52 ASTM C566, 127 ASTM C567/C567M, (table), 45–47 ASTM C595/C595M, (table), 20, 21–23, 24, 26, 50, 69 ASTM C617/C617M, 132 ASTM C618, (table), 24–26, 50, 69, 126 ASTM C637, 29 ASTM C637, (table) ASTM C666/C666M, 28, 64–65 ASTM C685/685M, 15, 69, 81 ASTM C917, 50 ASTM C989/C989M, (table), 26, 50, 69, 126 ASTM C1017/C1017M, (table), 50, 52 ASTM C1064/C1064M, (table), 137, 149 ASTM C1074, 132 ASTM C1077, (table), 137–138, 142 ASTM C1157/C1157M, 2, (table), 20, 21, 23, 24, 26, 50, 69 ASTM C1231/C1231M, 132 ASTM C1240, (table), 27, 50, 69, 126 ASTM C1260, 28 ASTM C1293, 28 ASTM C1602/C1602M, (table), 29–34, 47, 74 ASTM C1603, 32 ASTM C1610/C1610M, 42, 43 ASTM C1611/C1611M, (table), 42, 43, 56, 135–136 ASTM C1621/C1621M, 43 ASTM C1697, 27 ASTM D75/D75M, 28 ASTM Subcommittee C09.40, 112, 160–161 Automated Slump Adjustment System (ASAS), 111–115 automated slump flow monitoring, 113–115 automated water measurement, 125 B bacteriocidal admixtures, 37 bags, chemical admixture, 76 bags, as measurement, 71–72 basis of purchase, 11–15 batch characteristics, 167 batch persons, 84 batch plant, 82 certification, 165 processes of, 82–83, 83 (figure) refinements, (table) scale accuracy and, 84–88, 89–90 water and, 88–89 batch tickets, 123–128, 124 (figure) strength tests and, 152–153 See also delivery ticket batching, 73 accuracy limit, 72 process, 81 82 (figure) instruments, 82–83 sequence, 98 silica fume and, 27 tolerance, 11, 70, 76 water and, 30–31 See also scale; specific considerations; specific hoppers beam and poise weighing system, 87 (figure) beams, 150, 151 bench scales, 77 (figure) bicalcium aluminate (C2A), 18 bin, 81 bituminous coal, 25 blade wear, 97–98, 99 blades, 92–93, 95, 97, 98 (figure) blended hydraulic cements, 21–23 brand names, 126 build-up, drum, 97–98, 99 burden on the purchaser, 115–116 burns, 3–4 C calcinated clay, 26 calcinating, 23 INDEX calcium-aluminate cements, 37 calcium carbonate, 37 calcium chloride (CaCl2), 37, 118 See also flaked calcium chloride (CaCl2) calcium oxide (CaO), 18 calcium silicate hydrate, 24 calcium sulfate (CaSO4), 18 calculation of yield, 12, 13 calibrated volumetric tanks, 89 cellulose fibers, 37 cement, 19–24, 51, 52 See also specific types cement balls, 98 central-mix plant, 92, 94, 95, 104 See also stationary mixer central-mixed concrete, certification requirement, strength, 149 certification tests, 49–50 charging hopper, 98 chemical admixtures, 35–37 measurement, 76–78 mixing water in, 74 in self-consolidating concrete (SCC), 43 chert limitations, 28 chlorine limits, 32 clinker grinding process, 18–19 coal, 25 See also fly ash code requirements, See also specific requirements coefficient of variation, strength testing, 156 cold weather conditions, (figure), 115–116, 118, 138 coloring admixtures, 37 combined water, 30 communication with dispatch, 53–54 compartment, 81 completion of discharge, 111 composition, typical, 18 (figure) comprehensive strength tests, 149, 151, 169, 171–174, 175 (table), 176 (table) See also strength tests compression tests, 131–132 compressive strength tests, 50 computerized batch tickets, 110 computerized batching control system, 83, 156–157 concrete manufacturing facility See batch plant Concrete Plant Manufacturers Bureau (CPMB), 70, 72, 89–90, 92 Concrete Strength Testing Technician Certification, 150 concrete See aggregates; admixtures; specific components; specific practices tests; specific types; water concrete, central-mixed, concrete, ready-mixed, concrete, shrink-mixed, 7–8, 106 concrete strength See strength concrete, truck-mixed, 8, 106–109 constructability, 48, 56 construction cement, general, 19 continuous mixing, 81 contractor, contractor requirements, 141–142 core strength, 154–155 corrosion-inhibiting admixtures, 37 corrosion, reinforced steel, 32 cost See price course aggregate, 27–28 content, 166–67, 168, 168 (figure) size, 41 in transit water addition, 57 cumulative aggregate batches, 73 curing, 48, 131–132, 138, 152 cylinders, 132, 149–150, 151 test reports and, 50 weather conditions and, 138 D decumulative batcher, 83 delivery ticket, 52–54 See also batch ticket density (unit weight), 12 (figure), 12–13, 14, 15, 45–47 air content and, 66 relative, 52 test methods and, 132–133 uniformity tests and, 167, 168 See also density tests density tests, 47 (table) dial-head scale indicator, 83 discharge air content and, 44 (table), 63 completion of, 111 testing, 141 uniformity, 96–97 water addition and, 57, 58–59 discrepancies in yield, 11 division of responsibility, 45 documentation mixture proportions, 49, 53–54 nonmandatory, 174 See also batch ticket; delivery ticket dosages, admixture, 52 drum, 92–94, 94 (figure), 98 (figure), 98–99 See also blades; drum revolutions drum revolutions, 106, 111 dry mass, 49 durability, 48 air content and, 64 requirements, 41, 44, 53 181 182 User’s Guide to ASTM Specification C94 on Ready-Mixed Concrete E engineers, arbitration panel of, 159–160 entrapped air, 62 See also air-entrained concrete equilibrium density, 46 equipment, 91 automatic monitoring, 112–115 nonagitating, 102, 121–122 uniformity tests and, 96–97 See also agitators; blades; cylinders; drum; hopper; mixers; scale F fiber admixtures, 76 fiber reinforcement, 127 field curing, 48, 152 fine aggregate, 27 flaked calcium chloride (CaCl2), 76–77 flexural strength tests, 149, 151, 153 flowable fill, 37 flowing concrete, 36 fluidity, 55 See also slump test fly ash, 25, 126 foaming agents, 37 freeze-thaw resistance, 43, 44 See also air-entrained concrete; freeze-thaw tests freeze thaw tests, 64 frequency, strength testing and, 152, 172 –173, 173 (figure) frequency, testing, 145–146 freshly mixed, 11 front discharge drum, 91, 92 (figure) G general construction, 19–20, 22–23 general construction cement, 19 general purpose cement, 19, 24 glass fibers, 37 grade of slag, 126 grading, aggregate, 52 gray water, 33, 34 (figure) ground granulated blast furnace slag (GGBFS), 26 gypsum, 18, 32 H head pack, 98 head water, 98 high early strength cement, 20, 24 high sulfate resistant portland cement, 20–21, 24 hopper, batch, 69 hopper, charging, 98 hopper, weigh, 70, 81, 83 hot weather conditions, 10 (figure), 116–118, 138 hydration, 18, 24 See also mixing water; water hydration-control (stabilizer) admixtures, 37 hydraulic cement, 17–24, 69–71, 78 I ice, 74, 75 ID designation, 125 individual batcher, 73 initial water, 98 inspection of mixers and agitators, 97–99 plant, 129–130 water addition, 110 inspector, 144 See also inspection International System of Units (SI), in-transit water addition, 57–58 J job waste, 11 job-site water addition, 57, 58–59, 109–112, 125 K kaolinite, 18, 26 knowledgeable professional, 48–49 See also engineers; operator; technician L labcrete submittals, 50 lawyers, 160 length-diameter ratio (L/D), 155 lightweight aggregates, 28–29, 49 lightweight concrete density and, 143 mass per unit volume, 45–47, 47 (table) lignite, 25 limestone, 18, 23 See also cement limits of liability, 123 liquid admixture, 77–78 lithium-based additives, 37 load-cell scale system, 70 (figure) load-to-load variations, 57 low heat of hydration cement, 20, 24 low reactivity with alkali reactive aggregates, 24 low strength tests, 156, 159 M magnetic meters, 75 maintenance, mixer, 107 manufacturer, manufacturer responsibility limitations of, mixture proportions and, 47–48 plant inspection and, 129–130 INDEX proportions and, 52–53 purchaser specifications and, 52–53 quality and, 141 slump and, 59–60 mass, 11–12 aggregates and, 72, 82–83, 127–128 batching materials and, 69–70 per cubic foot, 132–134 per unit volume, 45–47, 132–134 material batching, tolerance and, 70–71, 72–73, 76 material tests, 49–50 materials aggregates, 27–29 See also aggregates air-entraining admixtures, 34–35 See also air-entraining admixtures cementious, 17, 18 (figure) chemical admixtures, 35–37 hydraulic cement, 17–24, 69–71, 78 manufacturer liberties and, 47–48 measuring, 69–79 supplementary, 24–27 water, 29–34, 31 (table), 34 (figure), 34 (table) See also water maximum aggregate size, 29 maximum allowable water content, 51 mean, strength testing, 156 measuring materials, 69–79 metakoalin, 26 metered water, 75, 127 meters, 134–135 See also specific meters mild exposure, 43 mineral admixtures, 24, 69, 126–127 See also admixtures; supplementary cementitious material (SCM) minimum cement content, 51, 52–53 minimum field standards weights and test loads, 85 (table), 87 mixer performance tests, 95–96, 104–106 mixers mass determination and, 97–99 slurry, stationary, 91–92, 95–96, 167 See also stationary mixer truck, 91, 92–94, 95–96, 108–109, 112–115, 167 See also truck mixer uniformity tests and, 165–166 water and, 57–58, 75–76 mixing revolutions, 106 mixing time, 102–104, 106 mixing trucks: water and, 75–76 mixing uniformity, 95–97 Mixing uniformity tests, 165–166 mixing water, 29–31, 33, 73–76 batch tickets and, 127, 128 in-transit, 57 measurement, 88–89 See also water mixture proportions, 45 documentation, 49 manufacturer responsibility, 52–53 purchaser responsibility, 50– 51 moderate exposure, 43 moderate heat of hydration and moderate sulfate resistance cement, 20, 24 moderate sulfate resistance, 19, 24 mortar unit weight, 168 N name, admixture specification, 52 National Institute of Standards and Technology (NIST), National Ready Mixed Concrete Association (NRMCA), 89, 92, 96, 98 National Ready Mixed Concrete Association (NRMCA) CIP-9, 161 National Ready Mixed Concrete Association (NRMCA) CIP-10, 161 NIST Handbook 105-1, (table), 86 NIST Handbook 44, 85 nominal maximum aggregate size, 29, 41–42 nominal slump, 58 nonagitating delivery, 121–122 non-potable water, 30, 31, 33, 47 normal distribution curve, strength test, 173 (figure) notes, NRMCA Plant Certification, 84–85, 121, 165 NRMCA Plant Certification Checklist, 130 NRMCA Publication 133, 154 NRMCA Publication 159, 13 O one-time water addition, 110–111, 112 open-top containers, 121 operations, 156–157 operator, 84 Option A See ordering Option A Option B See ordering Option B Option C See ordering Option C optional requirements, 20–21 ordering information, 41–54, 46 (table) ordering Option A, 41, 45 ordering Option “A plus,” 45 ordering Option B, 41, 45, 50 ordering Option C, 41, 45, 52–54 ordering option differences, 52, 53 See also specific ordering options oven-dry density, 46 oven-dry mass, 47 183 184 User’s Guide to ASTM Specification C94 on Ready-Mixed Concrete over-design, 175, 176–178 (table) over-under indicator, 87 (figure), 88 Ozyildirim, 65 P parts per million (ppm), 34 performance requirements, 19 plant certification, 165 plant inspection, 129–130 Plant Inspector Guide, 130 plasticizing admixture, 36 platform scales, 77 (figure) point of discharge See discharge polymer modifiers, 37 polypropylene fibers, 37 portland blast-furnace slag cement, 22 Portland cement, 17–18 See also hydraulic cement Portland-cement clinker, 18 portland limestone cement, 23 portland-pozzolan cement, 22–23 potable water, 30, 47 powdered admixtures, 76 pozzolan, 22, 23, 24, 25–27, 126 practice, compression tests and, 131–132 performance accepting tests and, 137–138 See also specific practices precision, air content testing, 61–62 precision statement, 151 preconstruction conference, preliminary sample, air content, 67 prescriptive requirements, 19 pressure air-meter measuring bowl (base), 167 price low strength test arbitration and, 160 purchaser approved changes, 117 producer, pumping aids, 37 pumping process specifications, 66 purchase order requirements, 1–2 purchaser, See also purchaser liberties; purchaser responsibility; purchaser specifications purchaser liberties, 2, 49 purchaser responsibility, 2, 48–49 cold weather and, 115–116 proportioning and, 50–51 slump and, 59–60 slump flow and, 58–59 test reports and, 54 water content and, 51 See also purchaser specifications purchaser specifications, 41–47, 47–48 admixtures and, 51–52 air content and, 62–63 compressive strength and, 48 See also purchaser responsibility Q quality assurance testing, 54 quality control (QC), 28, 130 quality portion, quantity, specific vs minimum, 51 R ready-mixed concrete, rear discharge drums, 91, 92 (figure) reasonable access, 129, 141–142 reclaimer units, 33, 34 (figure) reference documents, 5–6 (table) relative density, aggregate, 52 relative yield, 13 required average strength, 174 responsibility chain, responsibility groups, 45 See also manufacturer responsibility; purchaser responsibility retarding admixtures (Type B), 35, 36 ribbon-loading batching sequence, 98 rice-husk ash, 26 runoff water, 33–34 S safety issues, 3–4 sampling, 133–134 air content and, 64 of fresh concrete, 136–137 stationary mixers and, 129 strength tests and, 149 techniques, 2, 142 test methods and, 136 truck mixers and, 108–109 uniformity tests and, 104–105, 108–109, 165–166 sand, 18 (figure) saturated-surface-dry mass, 49 scale, 70 (figure), 77 (figure), 83 accuracy, 83, 84–88, 89–90 test procedures, 83–87 See also scale accuracy scale lever system, 70 (figure) seasonal variations, 11 See also weather conditions segregation, 42, 121 selection, cement, 20 self-consolidating concrete (SCC) admixtures and, 36 INDEX slump and, 55, 59 slump flow and, 42–43, 135–136 settling basin, 33, 33 (figure) 7-day comprehensive strength, 169 severe exposure, 43–44 shale, 26 shrinkage-compensating expansive cements, 37 shrink-mixed concrete, 7–8, 106 silica (SiO2), 18, 19 silica fume, 27, 126 size of course aggregate, 41–42 skin protection, 3–4 slag, 22, 23, 26, 126 slag cement, 26–27 slump cone, 135 (figure) slump flow, 42–43, 58–59, 113–115 requirements, 58–59 test methods and, 142–143 See also slump flow test; slump, tolerance slump flow test, 55–56, 144–147 See also automated slump flow monitoring slump meters, 113 slump responsibility, 60 slump tests, 55, 144–147, 167 batch uniformity and, 96–97 nonagitating delivery and, 122 test methods and, 135–136 slump tolerance See slump: tolerance slump, 42 changes, 36 (table) losses, 57, 59, 110 measurement, 56 (figure) responsibility, 59–60 test methods and, 135–136 test reports and, 50 target, 58 tolerance, 56–57, 58–59 uniformity tests and, 167 water addition and, 109–110 See also job-site water addition See also slump flow; slump flow test; slump test slurry mixer, slurry water (high solids content), 34 sodium oxide (Na2Oe), 19, 32 solid limits, water, 32–33 source, aggregate, 52 special admixtures (Type S), 36 specification, 1, 2, 27 See also specific types specification alteration, 2, 27 specified comprehensive strength, 48 specified minimum air content, 67 spillage, 14 standard deviation, strength testing, 156, 172, 173–174, 174–175 standard weights, 84 stationary mixer, 91–92, 95–96, 102, 103 (table) performance tests and, 104–105, 108–109 sampling and, 129 steel fibers, 37 storm runoff water, 33 strain-load test, 86–87 strength, 55 See also strength requirements; strength tests strength requirements, 153–157 failure to meet, 159–161 required average, 174–178, 175 (table), 176 (table) strength tests, 2, 50, 149–150 acceptance criteria, 153–157, 171–178 calculations, 171, 149, 151, 169, 171–174, 175 (table), 176 (table) See also over-design comprehensive, 149, 151, 169, 171–174, 175 (table), 176 (table) evaluation of, 151–152 field-curing and, 152 frequency, 152 low, 156, 159 See also strength requirements strike-off procedure, 133 sub-bituminous coal, 25 substitution load, 86 supplementary cementitious materials (SCM), 24, 69 See also mineral admixtures surface texture requirements, 48 T target slump, 58 technicians, 142–143, 149, 150 temperature hydration reactions and, 59 test methods and, 137 tests, 50, 144–145 terminology, 1, 7–8 test cylinders See cylinders test load, 86 test method, 5, 28 air content and, 133–135 density and, 132–133 reporting requirements and, 138 sampling and, 136 slump and, 135–136 temperature and, 137 See also specific test methods test reports, 54 test values, 95 testing procedures, 141–161 See also air content tests; certification tests; comprehensive strength test; density tests; materials 185 186 User’s Guide to ASTM Specification C94 on Ready-Mixed Concrete tests; mixer performance tests; scale; quality assurance tests; slump flow tests; slump tests; strength tests; test reports; uniformity tests time of set, 118 tolerance for aggregates and air content, 63–67 batching and, 11, 70 for chemical admixtures, 76 for mixing materials, 70–71, 72 slump, 56–57, 58–59 water meter and, 75 total mass (weight), 12 total mixing water, 88 transportation, 109 See also mixers transportation unit, 63 See also mixing trucks tricalcium aluminate (C3A), 18 Truck Mixer Manufacturers Bureau (TMMB), 92, 93, 94 (figure), 95, 107 truck mixer wash out and settling basin, 33 (figure) truck mixer, 75–76, 91, 92–94, 95–96 automated water measurement, 112–115 batch characteristics and, 167 sampling and, 108–109 water and, 57–58, 75–76 truck time, 112 truck-mixed concrete, 8, 106–109 Type A meter, 134 Type B meter, 134–135, 135 (figure) type, admixture, 52 U Uniform Arbitration Act, 160 uniformity requirements, 165–170, 166 (table) uniformity tests, 95–97 mixers and, 165–166 stationary mixers and, 104–105, 108–109 See also uniformity requirements uniformity See mixing uniformity; uniformity requirements; uniformity tests V variability, testing component, 172 variance, strength testing, 156 variation, with-in test coefficient, 152 vibration, effect on air content, 65 (table) Virginia Department of Transportation (VDOT), 65 viscosity, 42, 136 viscosity-modifying admixtures, 37 visual monitoring, batch, 84 Visual Stability Index (VSI), 136 volcanic tuff (ash), 25 volume loss, 14 volume purchase, 11 volumetric admixture dispenser, 79 (figure) volumetric batching, 81 W wash water, 30, 31, 32–33, 34, 34 (table) wash water slurries, 34 washout pits, 31, 32, 33 (figure) waste, 14 water, 18 (figure), 29–34, 31 (table), 34 (figure), 34 (table), 47 added, 88, 124 additives and slump, 57–59 batching uniformity and, 96 chemical admixture and, 74 hot, 116 job-site additions, 109–112 maximum allowable content of, 51 See also ice; mixing water; specific types water-cementitious materials (w/cm) ratio, 49, 51 water content, proportional to slump, 55 water from concrete production operations, 30 water losses, 14 water measuring system, 75 water meter, 75, 114 water per cubic measurement, 49 water reducer admixtures (Type A), 36, 78 water repellant admixtures, 37 weather conditions, 8, (table), (figure) aggregates and, 28 air content and, 43–44 cold, (figure), 115–116, 118, 138 hot, 10 (figure), 116–118, 138 weigh hopper, 70, 81, 83 weigh-on-the-belt configuration, 83 weighted water, 75, 127 wet mass, 47 Y yield, 13, 13 (figure) calculation, 12, 13 discrepancy of, 13–14 per cubic foot, 132–134